Body & Weight

Weight Loss Percentage Calculator

Tracking weight loss as a percentage of your starting weight is a fairer way to measure progress than pounds or kilograms alone. Enter your starting and current weight to see your percentage and the amount lost.

Calculate your weight loss percentage

kg
kg
Weight lost8.9%Clinically meaningful (≥5%)
Total lost
8 kg

Losing 5–10% of your starting weight delivers meaningful health benefits, even before reaching a "goal" weight.

This is an educational estimate, not medical advice. Consult a qualified professional.

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How the calculation works

The formula is: weight loss % = ((starting weight − current weight) ÷ starting weight) × 100. So if you started at 90 kg and now weigh 82 kg, you have lost 8 kg, which is (8 ÷ 90) × 100 = 8.9% of your starting weight.

Expressing loss as a percentage lets you compare progress fairly between people of very different sizes, and it is the measure used in clinical weight-management research and TV-style weight-loss challenges alike.

Why percentage matters more than the scale

Health guidelines focus on percentage because the benefits scale with it. Losing just 5% of your body weight can lower blood pressure, improve blood sugar control and reduce cholesterol; losing 10% brings even larger improvements and can put some cases of type 2 diabetes into remission. You do not have to reach an "ideal" weight to gain real, measurable health benefits.

The calculator above flags these milestones for you — 5% (clinically meaningful) and 10% (significant) — so you can see how close you are to the thresholds that matter most.

Setting a healthy pace

A safe, sustainable rate of loss is generally 0.5–1 kg (1–2 lb) per week, or roughly 0.5–1% of body weight. Faster loss is more likely to come from water and muscle and tends to rebound. Weigh yourself under consistent conditions — same time of day, similar clothing — and expect normal day-to-day fluctuations of a kilo or more from water and food. Watching the weekly trend is far more useful than reacting to a single reading.

Frequently asked questions

What is a good weight loss percentage?

Losing 5% of your starting weight is considered clinically meaningful, and 10% brings major health benefits. These targets matter more than reaching a specific "goal" weight.

How fast should I lose weight?

Most guidance recommends 0.5–1 kg (1–2 lb) per week, about 0.5–1% of body weight. Faster loss is harder to sustain and more likely to include muscle and water rather than fat.

Why track percentage instead of pounds?

Percentage accounts for your starting size, so it compares progress fairly between people and matches the way health benefits of weight loss are measured in research.

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Sources & references

  1. World Health Organization. "Obesity and overweight" fact sheet (BMI classification and health risks).
  2. Magkos F, et al. "Effects of moderate and subsequent progressive weight loss on metabolic function and adipose tissue biology in humans with obesity." Cell Metab. 2016;23(4):591–601.