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Weight loss percentage calculator
Weight loss percentage = (starting weight − current weight) ÷ starting weight × 100. From 90 kg (198 lb) to 84 kg (185 lb): 6 ÷ 90 × 100 = 6.7%. In pounds, 200 to 186 lb is 14 ÷ 200 × 100 = 7.0%. The calculator also shows your 5%, 10%, 15% and 20% milestones, your average pace per week, your progress to a goal, and has a challenge mode that ranks a group fairly by percentage.
How to calculate weight loss percentage
Weight loss % = (starting weight − current weight) ÷ starting weight × 100
- Subtract your current weight from your starting weight: that's what you've lost.
- Divide by your starting weight, not your current one.
- Multiply by 100.
Use the same units for both weights; kg, lb or stones all give the same percentage. If the answer is negative, you've gained. Weigh under the same conditions each time (morning, after the toilet, before eating), and use a weekly average if you weigh daily, because single days swing by a kilo or more (why your weight fluctuates).
Weight loss percentage chart
| Start | 5% | 10% | 15% | 20% |
|---|---|---|---|---|
| 60 kg | 3.0 | 6.0 | 9.0 | 12.0 |
| 70 kg | 3.5 | 7.0 | 10.5 | 14.0 |
| 80 kg | 4.0 | 8.0 | 12.0 | 16.0 |
| 90 kg | 4.5 | 9.0 | 13.5 | 18.0 |
| 100 kg | 5.0 | 10.0 | 15.0 | 20.0 |
| 110 kg | 5.5 | 11.0 | 16.5 | 22.0 |
| 120 kg | 6.0 | 12.0 | 18.0 | 24.0 |
| 130 kg | 6.5 | 13.0 | 19.5 | 26.0 |
| Start | 5% | 10% | 15% | 20% |
|---|---|---|---|---|
| 150 lb | 7.5 | 15.0 | 22.5 | 30.0 |
| 175 lb | 8.8 | 17.5 | 26.3 | 35.0 |
| 200 lb | 10.0 | 20.0 | 30.0 | 40.0 |
| 225 lb | 11.3 | 22.5 | 33.8 | 45.0 |
| 250 lb | 12.5 | 25.0 | 37.5 | 50.0 |
| 275 lb | 13.8 | 27.5 | 41.3 | 55.0 |
| 300 lb | 15.0 | 30.0 | 45.0 | 60.0 |
What is a good weight loss percentage?
5% is the first milestone that matters for health: guidelines call a sustained 3–5% loss clinically meaningful for blood sugar, triglycerides and diabetes risk. 10% brings bigger gains, including blood pressure and cholesterol. More in what happens when you lose 5% or 10%. For the speed, aim for 0.5–1% of your body weight a week: see how much weight you should lose a week.
Weight loss challenge: rank by percentage
In an office or family challenge, ranking by kilos or pounds lost favours the heaviest people: losing 6 kg from 112 kg is easier than 3.5 kg from 64 kg. Ranking by percentage of body weight lost puts everyone on the same footing:
| Rank | Lost | % |
|---|---|---|
| 1. Alex64 → 60.5 kg | 3.5 kg | 5.5% |
| 2. Sam112 → 106 kg | 6.0 kg | 5.4% |
| 3. Jordan88 → 84.2 kg | 3.8 kg | 4.3% |
| 4. Robin95 → 92.1 kg | 2.9 kg | 3.1% |
Use Challenge mode in the calculator: add everyone's starting and current weight, and it ranks them and keeps the list in your browser for the next weigh-in. Fair rules help: same scale, same time of day, similar clothes, one weigh-in day a week, and a final result from the trend or the last two weigh-ins, so nobody wins by dehydrating the day before. A challenge that rewards more than about 1% a week encourages crash diets; a prize for consistency works better.
Percent of excess weight loss (%EWL)
After weight-loss surgery, clinics often use excess weight loss: the share of the weight above a BMI of 25 that you've lost. %EWL = weight lost ÷ (starting weight − weight at BMI 25) × 100. For someone of 170 cm starting at 130 kg (287 lb), the weight at BMI 25 is 72.2 kg, so the excess is 57.8 kg. Losing 30 kg is 23.1% of body weight but 52% of the excess. The calculator shows it when you add your height. %EWL depends a lot on the starting BMI, so many researchers now prefer plain total weight loss %.
Typical weight loss percentages
| Approach | Average loss |
|---|---|
| Lifestyle program (Diabetes Prevention Program)goal 7%, diet and 150 min/week activity | about 7% in year 1, about 5% kept |
| Semaglutide 2.4 mg (STEP 1)68 weeks, with lifestyle advice | 14.9% (placebo 2.4%) |
| Tirzepatide 15 mg (SURMOUNT-1)72 weeks, with lifestyle advice | 20.9% (placebo 3.1%) |
When the percentage misleads
The first week or two often shows 2–3% because of water and glycogen, then the pace settles. And weight isn't all fat: if you lift and eat enough protein you can lose fat while the scale moves slowly. Track your waist or body fat too (body fat calculator), and plan the calories with the calorie deficit calculator.
Sources
- Jensen MD, Ryan DH, Apovian CM, et al. 2013 AHA/ACC/TOS guideline for the management of overweight and obesity in adults. Circulation 2014;129(25 Suppl 2):S102–S138.
- Diabetes Prevention Program Research Group. Reduction in the incidence of type 2 diabetes with lifestyle intervention or metformin. N Engl J Med 2002;346(6):393–403.
- Wilding JPH, Batterham RL, Calanna S, et al. Once-weekly semaglutide in adults with overweight or obesity (STEP 1). N Engl J Med 2021;384:989–1002.
- Jastreboff AM, Aronne LJ, Ahmad NN, et al. Tirzepatide once weekly for the treatment of obesity (SURMOUNT-1). N Engl J Med 2022;387:205–216.