Getting the calculator right
5 guides · You've used the calculator and want a more accurate answer.
The calculator asks five things, and four of them are guessed more often than measured. These pages explain what each input actually means, show the evidence behind our multipliers, and are honest about which boundaries are our design choice rather than a published value.
Body condition scoring
4 months and olderThe hands-on check behind every number this site produces: what you should feel over the ribs, what the waist should look like, and why cats can't be judged on the dog standard.
Activity level
4 months and olderWhere our activity multipliers come from, why kennel-dog research overstates them, and exactly where the published evidence stops and our own design begins.
Safe weight loss
4 months and older1–2% a week for dogs, 0.5–1% for cats, and what goes wrong when you go faster — including why rapid loss is specifically dangerous in cats.
Food energy density
All agesThe most-skipped field in the calculator, and the one that changes the answer most. Where the number hides on the packaging and why measuring cups fail.
Treats & the 10% rule
All agesTreats come out of the daily total, not on top of it — and the reason for the 10% ceiling is nutrient balance, not weight gain.