Cat Weight Goal
Free Cat Weight Goal calculator with clear step-by-step results.
About Cat Weight Goal
Feline weight loss has to be slow. Cats mobilise fat far less safely than dogs, and losing more than about 1-1.5% of body weight a week risks hepatic lipidosis, a serious liver condition. The plan therefore works backwards from a safe weekly rate: excess weight divided by the weekly loss gives the realistic timeline, and the feeding allowance is set at roughly 80% of resting energy requirement for the target weight — 70 × ideal weight^0.75 — rather than for the current weight.
Formulas
Timeline
Weeks = (current weight − ideal weight) ÷ (current weight × weekly loss %)
Feeding allowance
Target kcal/day = 70 × ideal weight^0.75 × 0.8
Worked example
With the default values below, Cat Weight Goal returns Weeks to Reach Ideal Weight of 27.4. Change any input above and every figure here is recalculated in your browser.
Inputs used
- Current weightminimum 0.1 kg
- 6.2 kg
- Ideal weightminimum 0.1 kg
- 4.5 kg
- Target weekly lossaccepts 0.1–3 %
- 1 %
- Current daily intakeminimum 1 kcal
- 280 kcal
Results
- Weeks to Reach Ideal Weight
- 27.4 weeks
- Weight to Lose
- 1.70 kg
- Weight-Loss Feeding Allowance
- 173 kcal/day
- Daily Calorie Reduction Needed
- 107 kcal/day
Step by step
- 1Values used
- 2Timeline
- 3Feeding allowance
- 4Weeks to Reach Ideal Weight= 27.4 weeks
- 5Weight to Lose= 1.70 kg
- 6Weight-Loss Feeding Allowance= 173 kcal/day
- 7Daily Calorie Reduction Needed= 107 kcal/day
Assumptions and limits
- The result is derived only from the 4 inputs listed above. Anything not among them is not part of the calculation.
- In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
- Figures are rounded for display to 2 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.
- Feline weight loss carries a real risk of hepatic lipidosis and must be supervised by a veterinarian. Do not restrict a cat's food based on a calculator, and never withhold food from a cat that has stopped eating — seek veterinary advice promptly.
How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.
Feline weight loss carries a real risk of hepatic lipidosis and must be supervised by a veterinarian. Do not restrict a cat's food based on a calculator, and never withhold food from a cat that has stopped eating — seek veterinary advice promptly.
Frequently Asked Questions
Why calculate calories for the ideal weight, not the current one?
Feeding to maintain the current weight maintains the current weight. Resting energy requirement is calculated from the target so intake falls to the level that sustains the cat you are aiming for.
Why is 1% a week the limit?
Rapid caloric restriction in cats can trigger hepatic lipidosis, where fat overwhelms the liver. It is potentially fatal and is the main reason feline weight loss is managed slowly and under veterinary supervision.
How do I know the ideal weight?
From a body condition score assessed by your vet, not from breed averages. A score of 5 out of 9 is ideal, and each point above it corresponds to roughly 10% over ideal weight.