Pet Care by the Numbers: Food Portions and Aquarium Volume
Get your pet's portions and habitat right — how to work out how much to feed a dog or cat, judge body condition, and measure an aquarium's true volume for safe, healthy stocking.
Dog Food Calculator
Verified formula Updated Jun 2026 Private — runs on your device
Verified formula
Private
Daily calories needed
1,059
- Resting energy requirement
- 662
For general information only — not financial, tax, legal or medical advice. Verify before you rely on it.
How to use the Dog Food Calculator
The Dog Food Calculator works out your daily calories needed, along with 1 related figure in an instant. Enter dog's weight and activity / life stage and the result updates as you type — it is free, needs no sign-up, and runs entirely in your browser so your figures stay private.
- Enter the dog's weight.
- Choose the activity / life stage.
- Read off your daily calories needed, together with resting energy requirement — the calculator updates automatically, with no button to press.
Formula
The Dog Food Calculator uses the formula:
Daily calories needed = 70 × (Dog's weight)^(0.75) × Activity ÷ life stage
Worked example
For example, with dog's weight of 20 kg and activity / life stage of Neutered adult (1.6), the daily calories needed is 1,059.
| Dog's weight | 20 kg |
|---|---|
| Activity / life stage | Neutered adult (1.6) |
| Daily calories needed | 1,059 |
|---|---|
| Resting energy requirement | 662 |
Results are estimates for educational use, not professional advice.
Frequently asked questions
First find resting energy: 70 × weight^0.75. Then multiply by an activity factor. A 20 kg neutered adult needs about 1,059 calories a day.
RER is the calories a dog burns at rest. The activity factor scales it up for life stage and exercise.
Divide daily calories by the calories per gram or cup on your dog food's label to find how much to feed.
No. It is a general guide. Your vet can tailor amounts for health conditions, breed and body condition.
The Dog Food Calculator uses the formula: Daily calories needed = 70 × (Dog's weight)^(0.75) × Activity ÷ life stage. For example, with dog's weight of 20 kg and activity / life stage of Neutered adult (1.6), the daily calories needed is 1,059.
Enter the dog's weight. Choose the activity / life stage. Read off your daily calories needed, together with resting energy requirement — the calculator updates automatically, with no button to press.
Related guides
Dog Food Table: Daily calories needed by Dog's weight
Reference table of daily calories needed for Dog Food across a range of dog's weight values — exact, engine-computed figures you can read off at a glance.
How to Calculate Dog Food: Formula, Steps & Examples
Learn how to calculate Dog Food — the formula explained step by step, with worked examples and a free calculator to check your answer.
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