The Baseline Numbers, Sourced Per Authority
Two named veterinary and animal-welfare bodies publish overlapping but not identical duration guidance. Neither is wrong; they’re just different planning targets.
| Supply |
ASPCA |
AVMA |
| Water |
At least 7 days per pet, replaced every 2 months |
At least 7 days per pet |
| Food |
7-10 days per pet (canned pop-top or dry), rotated every 2 months |
3-7 days per pet, rotated regularly |
| Medication |
2-week supply, waterproof container |
2-week supply, rotated and replaced so it doesn’t expire |
Where the two disagree (food duration), 7 days sits inside both ranges, which is why the worked example below uses 7 days as the default planning target. If your storage space allows it, ASPCA’s 10-day ceiling is a reasonable stretch goal; AVMA’s 3-day floor is the absolute minimum, not a target.
Ready.gov’s baseline framing is looser: a “several days’ supply” of food and water, with no per-pet gallon figure attached. Treat it as a general corroborating data point, not the number to build your math on. Use the ASPCA/AVMA durations above instead.
Water Math, Per Animal
Dogs have a vet-reviewed formula. PetMD, reviewed by Jennifer Larsen, DVM, PhD, DACVN, puts daily water need at approximately 1 ounce per pound of body weight per day, explicitly framed as a general estimate that varies by individual dog: not a fixed rule, and never a reason to restrict water without your vet’s direction.
| Dog’s weight |
Daily water (1 oz/lb) |
7-day supply |
| 10 lb |
10 oz (0.08 gal) |
70 oz (0.55 gal) |
| 25 lb |
25 oz (0.2 gal) |
175 oz (1.4 gal) |
| 50 lb |
50 oz (0.4 gal) |
350 oz (2.7 gal) |
| 90 lb |
90 oz (0.7 gal) |
630 oz (4.9 gal) |
Cats don’t have an equivalent vet-sourced formula. We looked for an AVMA-, ASPCA-, or vet-school-published ounce-per-pound figure for cats and didn’t find one, only pet-industry blog aggregations, which we’re not presenting as veterinary fact. For a cat, size water by the ASPCA/AVMA 7-day duration guidance rather than a per-pound calculation: pack enough bottled water to refill a cat’s bowl daily for the full duration, and lean on your vet for anything more precise about your specific cat.
Multi-animal households: add, don’t average. A 10 lb cat and a 90 lb dog don’t “average out” to a medium water need. Calculate each animal separately, then sum. This is the single most common go-bag math mistake: eyeballing a household total instead of adding real per-animal numbers.
The table above stops at 90 lb for a reason: past that, the water alone becomes a storage and weight problem rather than a jug you toss in the trunk, and the crate turns into a vehicle-fit question. Our giant breed dog disaster kit logistics guide runs the per-day math for a 100 to 150 lb dog and the space it actually needs.
One animal these numbers do not describe. Everything above is sized for a non-pregnant, non-lactating adult. This page publishes no water figure for a pregnant or nursing mother, and the per-pound rate above should not be read as one. Our evacuating a pregnant or nursing pet guide counts the mother plus her litter as more than one animal’s worth of food and water, which is this site’s own reasoning rather than a published figure. The food side of the same carve-out, where there are published numbers, is in the next section.
Food Math, Per Animal
Food math is messier than water math because calorie density varies by product. PetMD’s own vet-authored dog feeding chart (Jennifer Coates, DVM) is tied to one specific food’s calorie density and explicitly instructs readers to use their own bag’s feeding chart instead of a universal number. A dog’s actual needs can run 50% above or below “typical” depending on the individual and the food.
The rule that actually works: read your own bag. Every commercial pet food package prints a feeding chart in cups or ounces per day, scaled to your pet’s weight. Multiply that daily amount by your target duration (7 days, per the ASPCA/AVMA overlap above), and that’s your per-animal food number, not a number from this page or any other general guide.
As a rough planning range so you know what to expect before you check your own bag:
| Animal |
Typical daily dry food |
7-day supply |
| Cat (8-12 lb) |
0.25-0.5 cup (~1 oz per lb of body weight caloric range, food-dependent) |
~1.75-3.5 cups (roughly 0.4-1 lb) |
| Small dog (10-25 lb) |
0.75-1.5 cups |
~5-10.5 cups (roughly 1.1-3 lb) |
| Medium dog (25-50 lb) |
1.5-2.5 cups |
~10.5-17.5 cups (roughly 2.3-5 lb) |
| Large dog (50-90 lb) |
2.5-4 cups |
~17.5-28 cups (roughly 4-8 lb) |
These ranges are planning anchors, not a substitute for your actual food’s printed chart. The cups-to-pounds conversion above uses roughly 3.5-4.5 cups per pound, the widely cited range across manufacturer feeding guides and pet-nutrition sources for standard dry kibble; denser, small-kibble formulas run toward the high end of that range (more cups per pound, so less weight per cup) and larger, airier kibble toward the low end. Your own food’s actual density can still land outside this range, so confirm against the bag before you buy a container sized to hold it.
A pregnant or nursing mother is not a normal-appetite animal, and the gap is large enough to break the plan. Merck’s feeding guidance puts a lactating bitch at 2 to 4 times maintenance energy depending on litter size, and a lactating queen at 2 to 3 times normal food intake, both litter-size dependent in Merck’s own words, so the top of each range is not a worst case to round away. Run that through the arithmetic on this page and seven days of a lactating bitch’s real intake is 14 to 28 days of the ration the table above would size for her, which means a bag packed off her ordinary appetite holds roughly a quarter to a half of one week. Read what Merck says next to each figure, because it changes what the multiplier is for: for the bitch, Merck recommends ad lib feeding of a complete and balanced growth diet, and for the queen it states that supplementing an already balanced diet is not necessary and should be discouraged. So the multiplier is a statement about how much she eats, which is what a go-bag has to hold, and this page is not telling you to change what is in her bowl. Weigh or measure her current daily ration and multiply it by the Merck figure for her species before you multiply by days. Our evacuating a pregnant or nursing pet guide runs the rest of that situation, including late gestation, which Merck puts on different numbers again.
A therapeutic or prescription diet is not sized on this page. The read-your-own-bag rule still tells you what an animal eats in a day, but multiplying it by a duration assumes you can buy more of that food, and a veterinary diet moves on a retailer authorization tied to your clinic rather than an ordinary shelf purchase. Our can you stockpile a prescription diet page walks that channel and declines to size the reserve on purpose, the same way our stocking pet supplies when you can be cut off page does: how much of a prescribed diet to have in the house, and what to do if it runs out, are decisions for the veterinarian who prescribed it. This page does not name a substitute for one.
Medication Math
This one is the least ambiguous number on the page: the ASPCA, the AVMA, and the CDC all independently land on a 2-week supply of any medication your pet needs, and the ASPCA specifies keeping it in a waterproof container. Three independent authorities landing on the identical figure is about as solid as sourcing gets in this space. The AVMA adds a handling rule: stored medicine must be rotated and replaced so it doesn’t expire.
Per animal on medication, that means:
- 14 days of dosing, in whatever form the prescription takes (pills, liquid, injectable)
- A waterproof container: a zip-top bag inside a hard case, or a dedicated pill organizer
- A label identifying which pet each medication belongs to, critical the moment you’re managing more than one animal’s meds under stress
None of the three publishes a fixed calendar rotation interval for the medication itself; the AVMA’s kit note says only that these supplies must be rotated and replaced so they don’t expire. Build a medication check into whatever rotation schedule you already use for food and water (see emergency food and water storage for the 6-month CDC water-rotation cadence most households anchor to). To turn “refill before it lapses” into an actual date, the pet medication refill calculator works out when to reorder so you never drop below your 2-week cushion.
One thing the medication rule does not reach: a therapeutic or prescription diet is food, not medication, and the authorization it travels on lives between your clinic and your retailer account rather than in a pharmacy. That is a different failure mode when a clinic is closed or evacuated, and our can you stockpile a prescription diet page covers it. This page sizes neither that reserve nor a substitute for it.
Litter Math for Multi-Cat Households
Litter isn’t covered by ASPCA or AVMA duration guidance, so this section draws on pet-industry sources instead of veterinary authorities, flagged clearly, because that’s a different tier of source.
Boxes: Cats.com’s widely repeated rule of thumb is one litter box per cat, plus one extra, so 2 cats need 3 boxes minimum, sized at roughly 1.5 times the length of your largest cat. This is a pet-publisher guideline, not a clinical standard, but it’s a reasonable planning default in the absence of anything more authoritative.
Volume: neither ASPCA nor AVMA publishes a litter-volume figure, and the litter-industry source we checked (Litter-Robot) doesn’t publish a clean per-cat, per-day weight either. It only says a multi-cat household’s traditional boxes typically need full servicing about once a week. Rather than manufacture a number that isn’t published, treat litter as a “pack what keeps your boxes usable for the duration” item: bring enough fresh litter to service 2-3 boxes for 7 days, plus a scoop and sealable disposal bags, and size it against your own boxes’ capacity rather than a per-pound formula that doesn’t exist yet.
Scoop at least once daily under normal conditions; Cats.com specifically recommends twice daily in multi-cat homes, which is worth planning for if your evacuation kit needs to function for several days in a shelter or vehicle.
Worked Example: 2 Cats (10 lb each) + 1 Dog (50 lb), 7 Days
Here’s the full multiplication, using the ASPCA/AVMA 7-day overlap target:
Water:
| Animal |
Daily (formula) |
7-day total |
| Cat #1 (10 lb) |
Duration-based, not per-lb (no vet formula for cats) |
~7-day bottled reserve, refilled daily from stored supply |
| Cat #2 (10 lb) |
Same as above |
Same as above |
| Dog (50 lb) |
50 oz (1 oz/lb formula) |
350 oz = 2.7 gallons |
Because cats lack a per-pound formula, size each cat’s 7-day water the same practical way you’d size a 7-day human supply for a small household member: enough bottled water to refill a bowl daily. As a working estimate consistent with the dog formula’s scale (applying the same 1 oz/lb/day rate, though this is not vet-confirmed for cats), a 10 lb cat works out to about 70 oz (0.55 gallons) over 7 days, so two 10 lb cats add up to roughly 1.1 gallons combined for 7 days. Total household water: roughly 2.7 gallons (dog) + ~1.1 gallons (2 cats) ≈ 3.8 gallons, before adding a safety margin for heat or stress. Round up to the WaterBrick’s 3.5-gallon-per-brick sizing above, meaning this household needs at least two bricks for water alone.
Food (using the planning ranges above, confirmed against actual bag labels before buying containers):
| Animal |
7-day dry food estimate |
| Cat #1 (10 lb) |
~0.4-1 lb |
| Cat #2 (10 lb) |
~0.4-1 lb |
| Dog (50 lb) |
~2.3-5 lb |
Household food total: roughly 3-7 lb for 7 days, well within a single Gamma2 Vittles Vault’s capacity, with room for the household’s rotation buffer.
Litter (2 cats): 3 litter boxes minimum, plus enough fresh litter to service those boxes for 7 days. No published spec exists for exact volume, so size it against your own boxes rather than a fixed weight target.
Medication (if applicable): 14 days per medicated animal, in a waterproof, per-pet-labeled container. Two EZY DOSE weekly cases per medicated pet covers the full ASPCA/AVMA/CDC 2-week rule.
Household 7-day total, before containers and bag weight: approximately 3.8 gallons of water (~32 lb) + 3-7 lb of food + litter supplies (sized to your own boxes, no fixed weight target) + medication organizers. Water is the heaviest single item by an even wider margin than the food total alone suggests, so plan your container and carry strategy around that fact.
Worked Household Examples
The single 2-cats-plus-1-dog example above is one household shape. Here are three more, each fully multiplied out for both horizons the site uses: a 72-hour go-bag (FEMA/Ready.gov’s minimum disaster-supply window, the carry-it-out-the-door kit) and a 2-week shelter-in-place supply (the CDC’s more conservative standard, covered in full at long-term pet food and water storage). Water uses the 1 oz/lb/day rate (vet-reviewed for dogs, a working estimate only for cats, per the formula section above). Food uses the site’s 3.5-4.5 cups/lb kibble-density range applied to the per-species daily-cup ranges from the table above. Every number shows its arithmetic. Every animal in the three households below is a non-pregnant, non-lactating adult on an ordinary maintenance diet, so the two carve-outs above are the cases these totals do not describe.
Household A: 2 Cats (10 lb each) + 1 Dog (50 lb)
Water:
| Animal |
Daily (1 oz/lb) |
72-hour total |
2-week (14-day) total |
| Cat #1 (10 lb) |
10 oz |
30 oz (0.23 gal) |
140 oz (1.09 gal) |
| Cat #2 (10 lb) |
10 oz |
30 oz (0.23 gal) |
140 oz (1.09 gal) |
| Dog (50 lb) |
50 oz |
150 oz (1.17 gal) |
700 oz (5.47 gal) |
| Household total |
|
210 oz = 1.64 gal (≈13.7 lb) |
980 oz = 7.66 gal (≈63.9 lb) |
Food (cat row 0.25-0.5 cup/day; 50 lb dog sits in the medium-dog row, 1.5-2.5 cups/day; both converted at 3.5-4.5 cups/lb):
| Animal |
72-hour dry food |
2-week dry food |
| Cat #1 (10 lb) |
0.75-1.5 cups = ~0.17-0.43 lb |
3.5-7 cups = ~0.78-2 lb |
| Cat #2 (10 lb) |
Same as above |
Same as above |
| Dog (50 lb) |
4.5-7.5 cups = ~1-2.14 lb |
21-35 cups = ~4.67-10 lb |
| Household total |
≈1.3-3 lb |
≈6.2-14 lb |
Litter: 3 boxes minimum (2 cats + 1 per Cats.com’s “one per cat plus one” rule), sized 1.5x the largest cat’s length, with enough fresh litter to service them for the trip’s duration; no published per-cat weight figure exists (see litter section above).
Carriers: one per cat, e.g. the Sleepypod Atom (rated to 12 lb, Center for Pet Safety 5-star crash-tested, 17“L x 8.5”W x 10.5“H exterior) or the budget Petmate Two Door Kennel; one dog carrier or crate sized to a 50 lb dog, e.g. the Diggs Revol Collapsible Crate in its Medium (17-20in tall, 30-50 lb) size, which collapses to 40”L x 23“W x 10”H for storage.
Household footprint, 72-hour bag: roughly 13.7 lb of water + 1.3-3 lb of food + 2 cat carriers + medication organizer(s) if applicable. The consumables alone sit near the bottom of the 15-30 lb one-adult range discussed below, and that’s before carriers, the bag itself, and litter: treat this as a one-adult load only if a second person handles the carriers, and trim water toward the 72-hour floor if you have to carry everything alone.
Household footprint, 2-week shelter-in-place: roughly 63.9 lb of water + 6.2-14 lb of food, which is a stage-at-home reserve, not a carried load; two WaterBrick 3.5-gallon containers (see the product table above) hold only 7 gallons combined, which falls just short of the 7.66-gallon need above, so plan on three bricks (10.5 gallons) to actually clear it with margin, and a single Gamma2 Vittles Vault (up to 25 lb or 60 lb depending on size chosen) covers the food with rotation room to spare.
Household B: 2 Dogs (25 lb and 60 lb) + 2 Cats (9 lb and 12 lb)
Water:
| Animal |
Daily (1 oz/lb) |
72-hour total |
2-week (14-day) total |
| Dog #1 (25 lb) |
25 oz |
75 oz (0.59 gal) |
350 oz (2.73 gal) |
| Dog #2 (60 lb) |
60 oz |
180 oz (1.41 gal) |
840 oz (6.56 gal) |
| Cat #1 (9 lb) |
9 oz |
27 oz (0.21 gal) |
126 oz (0.98 gal) |
| Cat #2 (12 lb) |
12 oz |
36 oz (0.28 gal) |
168 oz (1.31 gal) |
| Household total |
|
318 oz = 2.48 gal (≈20.7 lb) |
1,484 oz = 11.59 gal (≈96.7 lb) |
Food (25 lb dog sits at the top of the small-dog row, 0.75-1.5 cups/day; 60 lb dog sits in the large-dog row, 2.5-4 cups/day; both cats use the 0.25-0.5 cup/day cat row):
| Animal |
72-hour dry food |
2-week dry food |
| Dog #1 (25 lb) |
2.25-4.5 cups = ~0.5-1.29 lb |
10.5-21 cups = ~2.33-6 lb |
| Dog #2 (60 lb) |
7.5-12 cups = ~1.67-3.43 lb |
35-56 cups = ~7.78-16 lb |
| Cat #1 (9 lb) |
0.75-1.5 cups = ~0.17-0.43 lb |
3.5-7 cups = ~0.78-2 lb |
| Cat #2 (12 lb) |
Same as above |
Same as above |
| Household total |
≈2.5-5.6 lb |
≈11.7-26 lb |
Litter: 3 boxes minimum for 2 cats (same one-per-cat-plus-one rule), sized to the larger of the two cats.
Carriers: four total, one per animal, no sharing. For the two dogs, a size-matched Diggs Revol crate per dog (Small: up to 17in/30 lb for the 25 lb dog; Intermediate: 20-26in/50-70 lb for the 60 lb dog); two cat carriers, e.g. two Petmate Two Door Kennels or Sleepypod Atoms depending on budget. Note the 12 lb cat sits exactly at the Atom’s stated weight ceiling: if your cat runs any heavier, size up or use the crash-tested cabin option instead.
Household footprint, 72-hour bag: roughly 20.7 lb of water + 2.5-5.6 lb of food. Four carriers plus consumables is realistically a two-person job; plan on splitting the load, or stage the car close before you start moving animals.
Household footprint, 2-week shelter-in-place: roughly 96.7 lb of water + 11.7-26 lb of food. This is this guide’s heaviest household by animal count, and its 11.59-gallon 2-week water need still fits inside a single WaterBrick 6-pack (21 gallons of capacity, with room to spare) rather than requiring a second, with a single Gamma2 Vittles Vault (up to 60 lb) covering food with room to spare.
Household C: 1 Dog (35 lb) + 1 Cat (10 lb) + 1 Rabbit
Rabbits don’t have a per-pound water or food formula from any authority the site has sourced. The House Rabbit Society’s own evacuation-kit guidance calls for about a week’s worth of hay, pellets, and water per rabbit, packed per animal, not a per-pound calculation (see rabbit and small pet emergency prep). That reference point is a 7-day figure, so it’s used directly for the 2-week column below at roughly double the HRS reference quantity, and treated as the full 72-hour requirement (not scaled down) for the shorter window, since the HRS doesn’t publish a shorter-duration figure to scale from.
Water:
| Animal |
Daily (1 oz/lb, dog/cat only) |
72-hour total |
2-week (14-day) total |
| Dog (35 lb) |
35 oz |
105 oz (0.82 gal) |
490 oz (3.83 gal) |
| Cat (10 lb) |
10 oz |
30 oz (0.23 gal) |
140 oz (1.09 gal) |
| Rabbit |
No per-lb formula published |
~1 week’s water per HRS (use the full HRS reference qty) |
~2x the HRS 1-week reference qty |
| Dog + cat subtotal |
|
135 oz = 1.05 gal (≈8.8 lb) |
630 oz = 4.92 gal (≈41 lb) |
Food (35 lb dog sits in the medium-dog row, 1.5-2.5 cups/day; cat uses the 0.25-0.5 cup/day row; rabbit uses HRS’s ~1-week hay-and-pellets reference, not a cups/lb conversion, since kibble density math doesn’t apply to hay):
| Animal |
72-hour dry food |
2-week dry food |
| Dog (35 lb) |
4.5-7.5 cups = ~1-2.14 lb |
21-35 cups = ~4.67-10 lb |
| Cat (10 lb) |
0.75-1.5 cups = ~0.17-0.43 lb |
3.5-7 cups = ~0.78-2 lb |
| Rabbit |
~1 week’s hay/pellets per HRS (full reference qty) |
~2x the HRS 1-week reference qty |
| Dog + cat subtotal |
≈1.17-2.57 lb |
≈5.44-12 lb |
Litter/bedding: the rabbit needs bedding serviced on the same cadence as the HRS kit guidance, not litter-box math (that’s a cat-specific system). The cat needs 2 boxes minimum, per Cats.com’s one-per-cat-plus-one rule applied consistently (1 cat + 1 extra = 2), sized to that cat’s length.
Carriers: one per animal, three total, no sharing across species. Dog: a size-matched crate or the Sherpa Deluxe carrier (Medium: up to 16 lb, so size up for a 35 lb dog; Large: up to 22 lb, still under-sized, so a hard-shell kennel is the better fit at this weight). Cat: any of the cat evacuation carrier picks. Rabbit: a top-load small-animal carrier per the rabbit emergency prep guide, chosen for top-load access specifically so you’re not reaching into a front door to grab a bolting rabbit.
Household footprint, 72-hour bag: roughly 8.8 lb of water (dog + cat) + 1.17-2.57 lb of food (dog + cat) + the rabbit’s ~1-week hay/pellet/water allotment (no published weight to add to the total) + 3 species-specific carriers.
Household footprint, 2-week shelter-in-place: roughly 41 lb of water (dog + cat) + 5.44-12 lb of food (dog + cat) + roughly double the rabbit’s HRS reference quantity of hay, pellets, and water, staged the same way as the other two households: bulk containers at home, portable amounts in the actual carried bag.
The Weight-of-Bag Reality Check
Every duration number above assumes you can actually carry what you calculate. None of the named authorities (not FEMA, not Ready.gov, not ASPCA, not AVMA) publish a standard for how much a go-bag should weigh relative to the person carrying it. That’s a genuine gap in the official guidance, and it matters: a mathematically “correct” 7-day, multi-pet supply can easily weigh more than one adult can carry alongside two cat carriers and a leashed dog.
A commonly repeated figure in general prepping and backpacking circles, not from a government or veterinary source, and labeled here as general guidance rather than an official standard, suggests a carried bag run about 10-20% of the carrier’s body weight, scaled to fitness level. For a 150 lb adult, that’s roughly 15-30 lb of carryable gear, which is far short of the roughly 32 lb of water alone in the worked example above.
What that mismatch means in practice:
- A full multi-day, multi-pet water supply is a stage-and-drive reserve, not a walk-out-the-door go-bag load. Keep the bulk (WaterBrick bricks, the Vittles Vault) staged near your vehicle or in your car, and carry only a portable, refillable amount (like the WePet 12 oz bottle) in a bag you might actually walk with.
- If you may need to evacuate on foot or with limited vehicle space, plan your carry capacity first, then work backward to how many days of supply actually fits, rather than calculating an ideal duration and assuming you’ll find a way to carry it.
- Multi-pet households should split the carry load across every adult available, and confirm ahead of time who carries which animal’s carrier versus which supply container, so it isn’t decided for the first time during an actual evacuation.
Weigh your own packed bag on a bathroom scale before you assume it’s carryable. The math above tells you what’s needed; only your own scale tells you what’s actually movable.
Vet-Wins Reminder
The numbers on this page are general planning estimates, not an individual prescription for your pet. Your veterinarian and the feeding chart on your pet’s specific food bag both take precedence over any general figure here, especially for medication dosing, which this page deliberately does not cover beyond the 2-week supply-duration rule.
If your pet shows signs of heat stress during evacuation (the AVMA lists anxiousness, excessive panting, restlessness, excessive drooling, unsteadiness, abnormal gum and tongue color, or collapse), treat it as urgent. The AVMA’s list of animal emergencies requiring immediate veterinary care separately names heat stress and heatstroke among the conditions that warrant an immediate vet visit. Move the animal to shade or a cool area, begin cooling with room-temperature wet towels, and get to the nearest vet hospital immediately; don’t wait to see if it resolves on its own.
For suspected poisoning, the ASPCA Animal Poison Control Center is available 24 hours a day, 365 days a year at (888) 426-4435 (a consultation fee may apply). Pet Poison Helpline is a second 24/7 option at 855-764-7661, which states a budget-tier per-incident consultation fee on its own site.
How We Chose
These container and organizer picks are built entirely from manufacturer-published specifications and the live Amazon product pages listed in each spec table’s source column. We did not test any of these products ourselves, and we say so plainly. Where a live ASIN couldn’t be confirmed during this research pass, we left it blank rather than guessing. Full methodology at /review-methodology.
Once your per-animal math is done, the next step is deciding who and what moves first: which pet to evacuate first covers triage logic for households that can’t move everyone and everything in one trip, and car loading with carriers for multiple pets covers fitting the carriers, containers, and supplies calculated here into an actual vehicle. For the underlying food and water storage rules referenced throughout this page, see emergency food and water storage for pets.