Every number on this site can be re-computed
This page explains where our formulas come from and how each figure is checked. Nothing here is hand-entered or proprietary: the energy equations follow published NRC and WSAVA sources, every calculation is re-verified by an automated consistency suite, and the full reference dataset is published openly under CC BY 4.0 so that anyone can reproduce the numbers independently.
Where the formulas come from
Our calculations are built on published veterinary nutrition methods. We use them; we do not claim to be certified by them, and no organisation listed here endorses this site.
| Component | Source basis | How it is used here |
|---|---|---|
| Resting energy requirement | NRC energy equations | RER = 70 × kg ^ 0.75 for dogs and cats |
| Cat clinical figure | NRC single-formula method | MER = 100 × kg ^ 0.67 — note the exponent is 0.67, not 0.75 |
| Maintenance multipliers | NRC 2006 / WSAVA Global Nutrition Guidelines | Applied as a two-step resting-energy calculation by species and life stage |
| Older-dog multipliers | NRC 2006 directly | 105 for older active dogs, 95 for inactive older dogs |
We use 0.67 for cats and 0.75 for dogs, and state both exponents on the pages where they appear.
How we check them
Every figure published on this site is produced by the same calculation engine that runs the calculators. None of it is typed in by hand. Before anything is published, it passes an automated consistency suite:
| Check | What it does | Count |
|---|---|---|
| Content audit | Every published number is recomputed from the engine and compared against the page | 1,243 checks |
| Engine unit tests | Formula behaviour, edge cases and species differences | 213 tests |
| Render checks | The calculators are run in a real DOM and the displayed results are asserted | 178 checks |
| Dataset reconciliation | Every row of the open dataset is reconciled against the engine, row by row | 164 checks |
These are our own automated checks, built for this site — they are a maintenance discipline, not a third-party certification. The audit is the same one that fails the build if a number on a page stops matching the engine.
One example of what the checks protect against: converting a daily calorie figure into grams depends on the energy density of the food — change the density and the grams move, while the calories do not. The site publishes density as a labelled assumption on every row, never as a hidden constant.
Why open data matters
Most feeding advice on the web arrives as a conclusion with no way to check it. A number you cannot reproduce is, in practice, a number you have to take on trust.
We publish the dataset behind these pages so the arithmetic can be followed rather than believed. That matters more now than it used to: when a search engine or an AI system summarises feeding advice, a source whose figures can be traced and recomputed is more useful than one whose method is hidden. We would rather be checkable than authoritative-sounding.
What we publish, and how you can reuse it
The full reference is available as a single JSON file and as one CSV per table, under a CC BY 4.0 licence:
- Pet Calorie Reference Dataset (JSON) — all tables plus metadata in one file
- energy_multipliers.csv — the full maintenance factor table
- daily_energy_typical.csv — daily calories by body weight
- portion_by_density.csv — grams per day at stated densities
- README — what each file contains and how to cite it
- Full reference tables, formatted for reading
You may copy, redistribute and adapt the data for any purpose, including commercially, provided you credit PetPortionCalc.com — Pet Calorie Reference Dataset and link back to the dataset page. Every row carries a source field pointing back to the page it was derived from.
What this site does not do
Stating the limits is part of being checkable. We do not:
- Give individual veterinary advice. This is a feeding calculator, not a clinic. A pet with a medical condition, a prescription diet, or a sudden change in appetite needs a veterinarian, not a website.
- Claim certification or compliance. We reference NRC methods, WSAVA guidelines and AAFCO nutrient standards as sources. We are not certified, approved or endorsed by any of them, and we are not a pet food manufacturer — AAFCO nutrient profiles are referenced only as background for nutrient-level questions.
- Endorse brands. Some pages contain affiliate links to products such as scales and storage containers. Which product you buy does not change any number on this site, and no manufacturer has any input into what we publish.
- Publish numbers without a source. If we cannot point to where a figure comes from, it does not go on the page.
How we fix mistakes
Corrections are welcome and are acted on. If a figure on this site does not match its stated source, or is inconsistent with current veterinary evidence, write to contact@petportioncalc.com with the page and the figure. Corrections are applied to the page and to the open dataset together, so the two never disagree.
Last updated: October 2026.