Dog Weight Loss Calculator
How much should an overweight dog eat? Enter the current body weight and body condition score to get an ideal target weight, a safe daily calorie target and a realistic timeline, based on standard veterinary nutrition equations.
Calculate the weight loss plan
BCS 5 out of 9 is ideal. Each point above 5 is roughly 10% to 15% excess weight.
Target (ideal) weight
24.5 kg
5.5 kg to lose from 30.0 kg
Daily calorie target
771 kcal / day
Treats and chews: no more than 77 kcal of this (the 10% rule)
Realistic timeline: 10 to 19 weeks
At a safe loss rate of 1% to 2% of body weight per week. Faster loss risks losing lean muscle, so slower and steadier wins.
This is a starting point, not a guarantee.
- Individual metabolisms vary by 15% to 20%, so weigh the dog every two weeks. Losing under 1% per week: reduce the food by about 10%. Losing over 2% per week: increase by about 10%.
- Sudden or stubborn weight gain can be caused by conditions such as hypothyroidism or Cushing's disease. A veterinary check is recommended before starting a strict diet.
- Count everything: treats, chews and table food should stay under 10% of the daily allowance, with 90% from the measured diet.
Turn calories into a portion
Calories are only the middle step. What you actually feed is grams. Take the energy figures from the bag or tin label and get the daily portion.
Usually printed as “metabolisable energy” on the label.
Only some labels give this. Grams are always more accurate than cups.
Daily portion
208 g / day
Your label says 3700 kcal per kg, so feed about 208 g per day to reach 771 kcal.
In cups
Add the kcal per cup from the label to see a cup measure. Cups vary a lot between foods, so weigh the food when you can.
Feeding a prescription weight loss diet?
Satiety and metabolic diets have very different energy densities, so gram amounts matter. Ask your veterinary clinic for a Vet.Portions handout, or start a 7-day free trial to get product-specific portions, printable client handouts and the full verified catalogue.
How the dog weight loss calculation works
The plan starts with the target weight. On the 9-point body condition scale, 5 is ideal and each point above that represents roughly 10% to 15% excess body weight:
Calories are then set at the resting energy requirement of the target weight, the energy the dog would use at rest at its ideal size:
A 30 kg dog at BCS 7 has a target weight of about 24.5 kg and a starting allowance of roughly 770 kcal per day. Feeding to the target weight, rather than the current weight, is what creates the gentle calorie deficit.
The two-week weigh-in rule
No equation can predict an individual dog's metabolism exactly. The plan only works if it is adjusted against real weigh-ins:
| Weight change after 2 weeks | What to do |
|---|---|
| Losing 1% to 2% per week | On track, keep the same amount |
| Losing under 1% per week | Reduce the daily food by about 10% |
| Losing over 2% per week | Increase the daily food by about 10% |
| No loss after 4 weeks despite measuring | Veterinary check for underlying causes |
Built for veterinary clinics
The full Vet.Portions dashboard turns this plan into a printable client handout with product-specific gram amounts, treat allowances and re-check schedules, plus growth plans, food transitions and parasite dosing support.
Frequently asked questions
- How fast should a dog lose weight?
- A safe rate is 1% to 2% of body weight per week. Faster loss risks losing lean muscle. Weigh every two weeks and adjust the food amount by about 10% if the rate falls outside that range.
- How many calories should an overweight dog eat?
- A common starting point is the resting energy requirement of the target weight: RER = 70 × (target weight in kg)0.75. Metabolisms vary by 15% to 20%, so reassess every two weeks.
- How do I work out my dog's ideal weight?
- On the 9-point body condition scale, each point above 5 is roughly 10% to 15% excess weight. Target weight = current weight ÷ (1 + excess %). A body condition assessment by your veterinary team is the most reliable method.
- Can treats stay in a weight loss plan?
- Yes, but treats, chews and table food should stay under 10% of the daily calorie allowance, with the remaining 90% from the measured diet. Many plans fail because treats were never counted.