How weight loss percentage is calculated
Weight loss percentage shows how much of your starting weight you've lost. It's a fairer way to compare progress than pounds alone: 10 pounds is a bigger change for someone who started at 150 pounds than for someone who started at 300.
It works the same in pounds or kilograms, because the units cancel out. If your current weight is higher, the result is the percent gained.
Worked example
You started at 200 lb and weigh 184 lb now. You've lost 200 − 184 = 16 lb, and 16 ÷ 200 × 100 = 8% of your starting weight. 5% of 200 lb is 10 lb, so you passed that mark at 190 lb. 10% is 20 lb, reached at 180 lb, so you're 4 lb away.
Why 5% to 10% is a common goal
The NIH's National Heart, Lung, and Blood Institute says that "a 5% to 10% weight loss can significantly improve your health and quality of life." The CDC notes that even modest weight loss can help blood pressure, cholesterol and blood sugar, and the NIDDK suggests 5, 7 or 10 percent goals for preventing type 2 diabetes. That's why the calculator shows how far you are from the 5% and 10% marks.
A safe, gradual pace
According to the CDC, people who lose weight at a gradual, steady pace, about 1 to 2 pounds a week, are more likely to keep it off. If you enter how many weeks it's been, the calculator shows your average weekly change. A slower pace is fine: small, lasting changes to eating, activity and sleep are what tend to stick.
If you're planning to lose weight, especially if you have a health condition, take medication, are pregnant or have a history of disordered eating, talk with a doctor or a registered dietitian. They can help you set a goal that's right for you.
Limitations
- Day-to-day weight swings with water, salt, food in your gut and hormones. Compare weights taken at the same time of day, or average a week of readings.
- The percentage doesn't show whether you lost fat, muscle or water.
- For children and teens, growth changes the picture. Talk with a pediatrician instead.
Want to see your body mass index at your new weight? Try the BMI calculator. To plan daily calories for a steady pace, use the calorie calculator.
Sources
- NHLBI (NIH): Overweight and obesity, treatment — "A 5% to 10% weight loss can significantly improve your health and quality of life."
- CDC: Losing weight — a 1 to 2 pound a week pace, and the 5% of 200 lb example.
- NIDDK: Your game plan to prevent type 2 diabetes — 5, 7 and 10 percent weight-loss goals.