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Pet Food Calculator — How Much to Feed Your Dog or Cat (NRC RER Formula)

Pet food calculator — RER + activity factor for dogs and cats, exact daily grams based on weight, age, neuter status, and kibble kcal/100g.

  • Runs locally
  • Category Calculator
  • Best for Getting a realistic range before a purchase, plan, workout, or schedule decision.
Vet advice always comes first — this tool uses the NRC general formula (RER = 70 × kg^0.75) as a baseline. Individual needs can drift ±20% by breed, body condition, and season.
Check the food bag. Typical dry kibble: 340–400 kcal/100g.
Daily kibble
237.1 g
DER (daily target): 854 kcal · RER (resting): 534 kcal · DER multiplier: ×1.60
Per-meal portion (2 meals)
Morning
119 g
Evening
118 g
Treat budget (≤ 10% of daily)
85 kcal
Source: NRC 2006 — Nutrient Requirements of Dogs and Cats; AAFCO feeding guidelines; WSAVA Global Nutrition Toolkit.

What this tool does

Free pet food calculator for dogs and cats. Stop eyeballing "one cup twice a day" — this tool runs the actual veterinary energy formulas: RER = 70 × kg^0.75 (the NRC resting-energy formula every vet school teaches), times a maintenance-energy multiplier that adjusts for life stage, neuter status, and four activity tiers from couch-potato to working sled dog. Then it divides by the kcal/100g printed on your kibble bag and gives you a precise daily gram amount, split into a morning and evening portion, plus a 10%-of-calories treat budget so training snacks don't quietly turn your dog into a small barrel. Works for puppies through seniors, neutered and intact, dogs and cats. Sources: NRC 2006 Nutrient Requirements of Dogs and Cats, AAFCO feeding guidelines, WSAVA Global Nutrition Toolkit. Vet advice always comes first — this is the baseline number to walk into the clinic with. 100% in your browser — no signup, no upload.

Tool details

Input
Numbers
The page exposes text boxes, numeric controls, file pickers, or structured inputs depending on the tool.
Output
Live result
The result area focuses on usable output, with copy, download, or preview actions when supported.
Privacy
Browser-side processing
The main tool logic does not call an external API, so inputs normally stay in the current tab.
Save / share
No account required
Open the page and use it; whether results survive refresh depends on the tool.
Performance budget
Initial JS <= 18 KB
No WASM budget is declared, keeping the tool quick to open on mobile.
Best fit
Calculator · Student
Category and role tags drive related tools, internal links, and quick fit checks.

How to use

  1. 1. Input

    Paste or drop your content into the tool panel.

  2. 2. Process

    Click the button. All processing is local in your browser.

  3. 3. Copy / Download

    Copy the result or download to disk in one click.

How Pet Food Calculator fits into your work

Use it for fast estimates, comparisons, and planning numbers before you make the final call.

Calculation jobs

  • Getting a realistic range before a purchase, plan, workout, or schedule decision.
  • Comparing scenarios by changing one input at a time.
  • Turning rough assumptions into a number you can discuss.

Calculation checks

  • Double-check units, dates, rates, and rounding assumptions.
  • Treat health, finance, tax, and legal outputs as planning aids, not professional advice.
  • Save the inputs that produced an important result so you can reproduce it later.

Good next steps

These links move the current task into a more complete workflow.

  1. 1 Water Intake Calculator Water intake calculator — daily water target by body weight, activity, climate. With drink-log to track today's progress. Open
  2. 2 Pet Age Calculator Pet age calculator — accurate dog/cat human-age equivalent, with breed size adjustment, lifespan stages. Open
  3. 3 Calorie Calculator Calorie calculator — daily calorie needs (BMR + TDEE), weight loss/gain targets, macro breakdown. Open

Real-world use cases

  • Resetting the bowl after your dog gets neutered

    Your 18 kg Border Collie just got neutered and you keep filling the same 2-cup scoop. Enter 18 kg, adult, neutered, normal activity, and a 380 kcal/100g kibble: the tool flips the multiplier from 1.8 to 1.6 and lands around 235 g/day, not the 265 g you fed before. That 30 g daily gap is exactly the weight creep most vets see six months post-surgery.

  • Switching an indoor cat from dry to wet food

    Your 4.5 kg neutered indoor cat moves to wet pouches at 85 kcal/100g instead of 360 kcal/100g kibble. Plug in 4.5 kg, neutered, low activity, and 85 kcal/100g: the gram output jumps to roughly 230 g/day across two meals. That number looks huge until you remember wet food is 78% water, and it stops you from underfeeding by eyeballing it against the old kibble portion.

  • Feeding a fast-growing puppy without overshooting

    A 5 kg, 3-month-old Lab puppy needs far more than its adult ratio. Enter 5 kg, puppy life stage, and a 420 kcal/100g puppy formula: you get about 180 g split into 3 to 4 small meals, since a puppy stomach can't hold one big bowl. Recheck weekly as the puppy gains, because at this stage the right amount changes every two weeks.

  • Budgeting treats on a training-heavy day

    You're clicker-training a 12 kg neutered terrier and burning through treats. The tool sets a 10% ceiling: with a ~560 kcal daily target, that's 56 kcal of treats, roughly 18 g of plain chicken. On a heavy session day, you subtract those 56 kcal from dinner so the day still totals 560, instead of stacking treats on top of a full bowl and quietly adding 8% calories.

Common pitfalls

  • Entering the kibble's weight per cup instead of kcal/100g. The bowl needs the calorie content (the "ME" line, e.g. 380 kcal/100g), not grams per cup. Mixing them up can double or halve your portion.

  • Scaling food linearly by weight. A 30 kg dog does not eat 3x what a 10 kg dog eats; the 0.75 exponent means it's closer to 2.3x, so big dogs get overfed if you guess.

  • Forgetting to recheck after neutering or weight loss. The right amount drifts 20-30% with neuter status and body condition, so re-run the numbers and feel the ribs at week 4, not just once.

Privacy

Every calculation runs entirely in your browser. Your pet's weight, age, neuter status, activity tier, and kibble kcal all stay on your device and are never uploaded. If you share the result link, those input values are encoded in the URL so the recipient sees the same numbers, so only share that link with people you trust. No signup, no tracking of your pet's data.

FAQ

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Made by Toolora · 100% client-side · Updated 2026-06-13