Dog Weight Loss Calculator

How do I use the dog weight loss calculator?

1. Enter your dog’s current weight.
2. Enter the target weight from your vet, or estimate it from the body condition score (BCS).
3. Enter the kcal per cup of the food you’ll use. A weight-loss formula usually has fewer calories per cup.
4. Read the daily calories, cups, weekly pace and time to goal.
5. Weigh your dog every 2 weeks and compare with the schedule below.

What formula does the dog weight loss calculator use?

Using the ideal weight is the key step. Calories calculated from the current weight feed the extra pounds. The 1–2% weekly pace for dogs is from the AAHA weight management guidelines. The BCS rule (about 10% over ideal per point above 5 on the 9-point scale) comes from Laflamme’s body condition system, and works best for scores 6–9. We count weeks with a compounding percentage because 1% of a lighter dog is fewer pounds.

How is the calculation done?

With the default example, a 60 lb dog with a 50 lb target, eating a 350 kcal/cup weight-management food:

1. Use the target weight, not the current one: 50 lb ÷ 2.2046 = 22.68 kg.
2. RER at target weight = 70 × 22.68^0.75 = 727 kcal.
3. Weight-loss factor 1.0: daily target = 727 kcal (floor without a vet: 0.8 × RER = 582 kcal).
4. Convert to food: 727 ÷ 350 kcal/cup = 2.08 = 2⅛ cups a day, treats included.
5. Safe pace is 1–2% of body weight a week: 0.6–1.2 lb a week at the start.
6. Weeks to lose 10 lb at that pace: about 10–19 weeks.

Worked example: using the body condition score

Your 40 lb dog scores 8 of 9 at the vet. Ideal weight ≈ 40 ÷ (1 + 0.1 × 3) = 40 ÷ 1.3 = 30.8 lb. RER at that weight is 505 kcal, so the plan starts near 510 kcal a day. At 1–2% a week, that’s a project of several months, which is normal. Slow and steady is what keeps the weight off.

Weight loss schedule: 60 lb to 50 lb

Staying between the two columns means the plan is working. Above the 1% column for a month? Cut calories by 5–10% with your vet’s OK. Below the 2% column? Add a little food.

Why does weight loss matter for dogs?

Extra weight strains joints and is linked to arthritis, diabetes and breathing problems. In a lifetime study of Labrador Retrievers, dogs kept lean lived a median of about 1.8 years longer than their littermates fed more (Kealy et al., 2002). Losing even part of the extra weight can make a visible difference to how your dog moves.

When should you see your vet?

• Before you start, to confirm the target weight and rule out hypothyroidism or other illness.
• If your dog loses more than 2% a week, seems hungry and weak, or loses muscle.
• If your dog doesn’t lose weight after a month on the plan.
• If your dog has a medical condition or takes medication.