How it works
Enter two measurements in the same unit. The calculator subtracts the previous weight from the current weight, then expresses that difference as a percentage of the previous weight.
Absolute change = current weight − previous weight
Percentage change = (current weight − previous weight) ÷ previous weight × 100
Example
A change from 4.5 kg to 4.2 kg is −0.3 kg. The percentage change is (4.2 − 4.5) ÷ 4.5 × 100 = −6.7%.
Limits of this calculator
This tool only calculates a difference between two measurements. It does not assess the cause or importance of a weight change. Discuss concerns about your cat with a veterinarian.
FAQ
How is cat weight change calculated?
Subtract the previous weight from the current weight. Divide that result by the previous weight and multiply by 100 for the percentage change.
Should I use kilograms or pounds?
Use either unit, but use the same one for both measurements. The percentage result is the same in kilograms and pounds.
Does this calculator assess my cat's health?
No. It reports the arithmetic difference only and does not interpret the result.
Is my cat's weight saved?
No. Values stay in your browser and are not uploaded, saved or shared.