Why track weight loss as a percentage
Losing 20 pounds means something different for a person who weighs 160 pounds than for one who weighs 300. Percentage weight loss puts everyone on the same scale, which is why doctors and clinical trials of diets and weight loss medicines report results this way.
- Percent lost = (starting weight − current weight) ÷ starting weight × 100
- Average loss per week = weight lost ÷ weeks since you started
- BMI = weight in kg ÷ (height in m)²
Worked example
You started at 220 lb, weigh 198 lb now, are 5 ft 8 in (68 in) tall and started 20 weeks ago.
- Weight lost: 220 − 198 = 22 lb.
- Percent lost: 22 ÷ 220 = 10.0% of your starting weight.
- Average rate: 22 ÷ 20 = 1.1 lb a week, or 0.5% of body weight a week.
- BMI went from 33.5 to 30.1. At your height, a BMI of 25 corresponds to about 164 lb.
What the milestones mean
| Weight lost | Typical health effects |
|---|---|
| 3 to 5% | Lower triglycerides and blood sugar; reduced risk of type 2 diabetes |
| 5 to 10% | Lower blood pressure and LDL cholesterol; better mobility |
| 10 to 15% | Less sleep apnea and fatty liver; less knee pain; possible diabetes remission |
| 15% or more | Large improvements in many weight-related conditions |
These are averages from clinical studies; individual results vary.
A sensible pace
The CDC suggests a steady loss of about 1 to 2 pounds a week. Losses are often faster in the first weeks because of water and glycogen, then slow down. A long plateau is normal: as you get lighter, you burn fewer calories, so the deficit that worked at the start shrinks.
Make the loss last
- Eat enough protein and keep doing strength training to preserve muscle.
- Track trends, not single days. Daily weight can swing by 2 to 4 pounds with salt, water and digestion; a weekly average is more reliable.
- Measure your waist too. It can keep shrinking while the scale stalls.
- Plan for maintenance. Keeping the weight off depends on habits you can sustain: regular meals, activity, sleep and support.
Talk to your doctor before starting a weight loss program if you have a medical condition, take medications for diabetes or blood pressure, or are losing weight without trying.
This calculator is for general information and education. It is not medical advice and does not replace the judgment of a doctor, nurse or pharmacist who knows the full clinical picture.