How do you calculate weight loss percentage?
Subtract your current weight from your starting weight, divide by the starting weight, and multiply by 100. Losing 15 lb from 200 lb is 15 divided by 200, which is 7.5 percent.
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Weight loss percentage calculator
See what share of your starting weight you have lost, how far along you are to a goal, and where the 5 and 10 percent marks fall for you.
The percent, and what it means
See what share of your starting weight you have lost, how far along you are to a goal, and where the 5 and 10 percent marks fall for you.
Methodology
How the percentage is calculated
One division, then two markers that make the number mean something.
- 01
Change from the start
Starting weight minus current weight is the amount lost. Divided by the starting weight and multiplied by 100, it is the percent of body weight lost.
- 02
Progress to a goal
With a goal weight, the amount lost is compared with the total you set out to lose, shown as a share of the way there, capped at 100.
- 03
The 5 and 10 percent marks
The weights at 5 and 10 percent below your start are shown and ticked off as you pass them, because that range is where health guidance sees measurable change.
Keep exploring
Keep the trend going
A percentage is a snapshot. The next few weeks are where it moves.
Frequently asked questions
Why does 5 to 10 percent matter?
Health guidance from the CDC and others points to 5 to 10 percent of starting weight as the range where blood pressure, blood sugar, and cholesterol tend to improve. It is a marker, and the calculator shows the weight it corresponds to for you.
Is percentage better than pounds for tracking?
It is fairer across body sizes. Ten pounds is 5 percent for someone starting at 200 lb and 3 percent for someone starting at 330 lb. Percentage is also how most challenges and studies report results.
What if I have gained weight since my start?
The calculator shows the gain as a negative change rather than an error. Weight moves with water, sleep, salt, and time of day, so compare weeks rather than single days.
Sources and further reading