RER is resting energy (70 × kg^0.75). MER is RER multiplied by an activity/life-stage factor to give daily calories.

How do I get cups per day?

Enter your food's calories per cup (on the bag). Cups/day = daily calories ÷ kcal per cup.

Should I trust this over my vet?

No — it's a starting estimate. Your vet accounts for body condition, health and specific diets.

Why is body weight raised to the power of 0.75?

Energy use does not scale in a straight line with weight. A dog twice as heavy does not burn twice the calories, because heat loss scales with surface area rather than mass. The 0.75 exponent is the standard metabolic-scaling figure used in veterinary nutrition, which is why a 40 kg dog needs far less than double what a 20 kg dog needs.

The cups-per-day number looks wrong - what should I check?

Check the calories-per-cup figure you entered. Foods vary from roughly 300 to over 500 kcal per cup, so using a number from a different bag can be off by half. Use the value printed on your own bag, and measure with a proper measuring cup rather than the scoop that came in the box - scoop sizes are not standardised.

Does this tool upload my data?

No. Everything runs right in your browser, so your data never leaves your device — it even works offline once the page has loaded.

🍖 Dog & Cat Calorie Calculator

How much should you feed your dog or cat? Search your breed to prefill a typical weight and see its healthy adult range, or enter the weight yourself, then pick a life stage or activity level to estimate daily calories using the veterinary RER × activity-factor method. Optionally enter your food's calories per cup to get cups per day. Free, instant, and private in your browser.

Breed (optional — fills weight + ideal range)

Weight

Life stage / activity

Food kcal per cup (optional)

Daily calories

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Resting (RER)

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Daily energy is estimated as RER × an activity factor. Resting Energy Requirement (RER) = 70 × (body weight in kg)^0.75, then Maintenance Energy (MER) multiplies it by a factor for life stage and activity. These are starting points — adjust to keep a healthy body condition and follow your vet's guidance, especially for puppies, kittens, pregnancy, or medical diets.

Private by design. This tool runs entirely in your browser — nothing you enter is uploaded or stored, and it works offline.

About

Daily energy needs are estimated in two steps. First, the Resting Energy Requirement (RER) = 70 × (body weight in kg)^0.75, the calories a pet burns at rest. Then the Maintenance Energy Requirement (MER) multiplies RER by a factor for life stage and activity — for example, a neutered adult dog is about 1.6× and an active dog higher, while a neutered adult cat is about 1.2×. Puppies, kittens, and pregnant or nursing pets need much more. These are starting estimates; monitor body condition and follow your veterinarian's guidance, especially for weight-loss or medical diets.

How to use

Choose Dog or Cat and enter the weight (kg or lb).
Pick the life stage or activity level.
See resting (RER) and daily (MER) calories; optionally add kcal per cup for cups/day.

FAQ

What is RER and MER?: RER is resting energy (70 × kg^0.75). MER is RER multiplied by an activity/life-stage factor to give daily calories.
How do I get cups per day?: Enter your food's calories per cup (on the bag). Cups/day = daily calories ÷ kcal per cup.
Should I trust this over my vet?: No — it's a starting estimate. Your vet accounts for body condition, health and specific diets.
Why is body weight raised to the power of 0.75?: Energy use does not scale in a straight line with weight. A dog twice as heavy does not burn twice the calories, because heat loss scales with surface area rather than mass. The 0.75 exponent is the standard metabolic-scaling figure used in veterinary nutrition, which is why a 40 kg dog needs far less than double what a 20 kg dog needs.
The cups-per-day number looks wrong - what should I check?: Check the calories-per-cup figure you entered. Foods vary from roughly 300 to over 500 kcal per cup, so using a number from a different bag can be off by half. Use the value printed on your own bag, and measure with a proper measuring cup rather than the scoop that came in the box - scoop sizes are not standardised.
Does this tool upload my data?: No. Everything runs right in your browser, so your data never leaves your device — it even works offline once the page has loaded.