What is my weight loss percentage?
Type your starting weight and your current weight. The weight loss percentage calculator shows the percent of your starting weight you have lost, or, from a percent, the weight that reaches it.
- Weight loss percentage
- 7.5%
Going from 200 lb to 185 lb is a weight loss of 7.5% (15 lb).
5% to 10%: the NIH first goal
- No loss
- Under 5%
- 5% to 10%: the NIH first goal
- More than 10%
- Weight lost
- 15 lb
Weight loss percentage: 7.5%. Going from 200 lb to 185 lb is a weight loss of 7.5% (15 lb).
This calculator gives general information only. It is not medical advice and does not replace a doctor or other health care provider. Talk with a professional about your results. Terms of use
How to calculate
Works out the percent of body weight lost from a starting and a current weight, the weight lost, or the weight to reach a percent goal such as the 5% to 10% that NIH suggests.
Example with the default inputs (Starting weight 200 lb, Current weight 185 lb): Going from 200 lb to 185 lb is a weight loss of 7.5% (15 lb).
Formula: Weight loss percentage = (starting weight − current weight) ÷ starting weight × 100.
- Both weights are measured the same way (same scale, same time of day, similar clothing).
- A current weight above the starting weight gives a negative percent: a gain.
Worked examples
Each example is checked against the calculator on every build.
- Starting weight 200 lb, Weight loss percentage 10% gives Current weight 180 lb, Weight lost 20 lb.Source: NIDDK (NIH), Your Game Plan to Prevent Type 2 Diabetes: lose 5 to 10 percent of your weight; at 200 pounds a 10 percent goal is 20 pounds, https://www.niddk.nih.gov/health-information/diabetes/overview/preventing-type-2-diabetes/game-plan
- Starting weight 200 lb, Weight loss percentage 5% gives Current weight 190 lb, Weight lost 10 lb.Source: CDC, Steps for Losing Weight: a 5% weight reduction for a person who weighs 200 pounds is 10 pounds, https://www.cdc.gov/healthy-weight-growth/losing-weight/index.html
- Starting weight 180 lb, Current weight 171 lb gives Weight loss percentage 5%, Weight lost 9 lb.Source: NIDDK (NIH), Your Game Plan to Prevent Type 2 Diabetes: lose 5 to 10 percent of your weight; at 200 pounds a 10 percent goal is 20 pounds, https://www.niddk.nih.gov/health-information/diabetes/overview/preventing-type-2-diabetes/game-plan
- Starting weight 209.4 lb, Current weight 188.5 lb gives Weight loss percentage 10%, Weight lost 20.9 lb.Source: NIDDK (NIH), Your Game Plan to Prevent Type 2 Diabetes: lose 5 to 10 percent of your weight; at 200 pounds a 10 percent goal is 20 pounds, https://www.niddk.nih.gov/health-information/diabetes/overview/preventing-type-2-diabetes/game-plan
- Starting weight 150 lb, Current weight 156 lb gives Weight loss percentage -4%, Weight lost -6 lb.Source: CDC, Steps for Losing Weight: a 5% weight reduction for a person who weighs 200 pounds is 10 pounds, https://www.cdc.gov/healthy-weight-growth/losing-weight/index.html
How it works
Type two of the three values; the calculator finds the third from
percent = (start − current) ÷ start × 100
- current = start × (1 − percent ÷ 100)
- start = current ÷ (1 − percent ÷ 100)
Weight lost = start − current, shown in pounds (1 decimal place) or kilograms in Metric. The percent shows to 2 decimal places. Weights are converted to kilograms first (1 lb = 0.45359237 kg); the percent does not depend on the unit. The maths runs in floating point and rounds for display only.
The percent shows a band:
| Percent | Band |
|---|---|
| below 0 | No loss |
| 0 to under 5 | Under 5% |
| 5 to under 10 | 5% to 10%: the NIH first goal |
| 10 or more | More than 10% |
A current weight above the starting weight gives a negative percent and a negative weight lost: a gain.
Rules
- Each weight is above 0 and at most 700 kg (1,543 lb). The percent is from −500% up to, not including, 100%. A typed value outside that shows a message on its field; a solved value outside it gives no answer.
- With all three values typed, they must fit the equation; otherwise the page says the values do not agree.
Worked examples by hand
A 10% goal from 200 lb (NIDDK). Current = 200 × (1 − 0.10) = 180 lb; weight lost = 20 lb.
A 5% goal from 200 lb (CDC). Current = 200 × 0.95 = 190 lb; weight lost = 10 lb.
180 lb to 171 lb. (180 − 171) ÷ 180 × 100 = 5%; 9 lb lost.
95 kg to 85.5 kg. (95 − 85.5) ÷ 95 × 100 = 10%; 9.5 kg lost.
A gain, 150 lb to 156 lb. (150 − 156) ÷ 150 × 100 = −4%; weight lost = −6 lb.
Other questions people ask
How do I calculate weight loss percentage?
Subtract your current weight from your starting weight, divide by the starting weight, and multiply by 100. From 180 lb to 171 lb: (180 − 171) ÷ 180 × 100 = 5%.
What is 5% or 10% of my body weight?
Multiply your starting weight by 0.05 or 0.10. At 200 lb, 5% is 10 lb (a goal of 190 lb) and 10% is 20 lb (a goal of 180 lb).
Why does NIH suggest losing 5% to 10%?
NIDDK, part of NIH, suggests a first goal of 5 to 10 percent of your starting weight, for example within 6 months, because even this modest loss can improve blood pressure, cholesterol and blood sugar. CDC says the same about modest weight loss.
Why use a percent instead of pounds?
A percent compares fairly between people of different sizes. Losing 10 lb is 5% of 200 lb but 8% of 125 lb.
What does a negative percent mean?
That the current weight is above the starting weight: a gain. From 150 lb to 156 lb is −4%.
Does the unit matter?
No. The percent is the same in pounds or kilograms, as long as both weights use one unit. 95 kg to 85.5 kg is 10%, the same as 209.4 lb to 188.5 lb.