Weight Loss Percentage Calculator
This weight loss percentage calculator finds the percent of body weight lost, the amount lost, and progress to an optional goal in pounds or kilograms. It is simple math, not medical advice.
How to use
- Choose pounds or kilograms. Switching the unit does not convert the number you typed.
- Enter the starting weight and the current weight. Starting weight must be greater than zero.
- Optionally enter a goal weight that is greater than zero and lower than the starting weight.
- Read the percent lost, the amount lost, and, with a goal, the percent of the way there.
Formula
Percent lost equals (starting weight minus current weight) divided by starting weight, times 100. Amount lost equals starting weight minus current weight. Goal progress equals amount lost divided by (starting weight minus goal weight), times 100. The percentage is the same in pounds or kilograms.
Example. Going from 200 lb to 180 lb loses 20 lb, which is 20 / 200 × 100 = 10%. A goal of 160 lb is 40 lb below the start, so 20 / 40 × 100 = 50% of the way there.
Example. The same drop from 90 kg to 81 kg is also 10%, because 9 / 90 × 100 = 10%.
Not medical advice
This page only divides two weights. It does not set a healthy target, account for body composition, or replace a clinician. Talk to a doctor about weight-loss targets.
Frequently asked questions
How do I calculate weight loss percentage?
(Starting weight - current weight) / starting weight x 100.
If I went from 200 to 180 lb, what percent is that?
20 / 200 x 100 = 10%.
Does it work in kilograms?
Yes. The percentage is the same in pounds or kilograms.
Can it show progress to a goal?
Yes. Enter a goal weight to see the percent of the way there.
Is this medical advice?
No. Talk to a doctor about weight-loss targets.
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