Scale weight on its own can be misleading: eight kilograms means something different to a person who started at 150 kg and one who started at 70. The percentage of body weight lost puts the change on a common scale, and it is the unit that clinical guidelines use when they set goals. This calculator shows the percentage you have lost, how far you are towards a goal weight, and the weights that would equal a 5 and a 10 percent loss from where you began.
Those two thresholds matter because research has found that losing 5 to 10 percent of body weight can bring measurable improvements in blood pressure, blood sugar and cholesterol, even when the person remains above their target weight.
How to use the weight loss percentage calculator
- Enter your starting weight, the figure when you began.
- Enter your current weight.
- Enter a goal weight if you have one. It is optional; leave it at 0 to skip the progress figures.
- Read the results: weight lost, percentage lost, what remains and the weights at 5 and 10 percent.
Weight loss percentage formula
Percent lost = weight lost ÷ starting weight × 100
Progress to goal = weight lost ÷ (starting weight − goal weight) × 100
Weight at a p% loss = starting weight × (1 − p ÷ 100)
The 5 to 10 percent benchmark comes from the 2013 AHA/ACC/TOS Guideline for the Management of Overweight and Obesity in Adults (Jensen et al., Circulation 2014;129(suppl 2):S102–S138), which describes this range as producing clinically meaningful health benefits. The percentage is always based on the starting weight so that it does not change as you lose.
Worked example
You started at 90 kg, now weigh 82 kg and are aiming for 75 kg.
- Weight lost = 90 − 82 = 8 kg
- Percent lost = 8 ÷ 90 × 100 = 8.9%
- Remaining = 82 − 75 = 7 kg; progress = 8 ÷ 15 = 53% of the way
- A 5% loss is 90 × 0.95 = 85.5 kg and a 10% loss is 90 × 0.90 = 81 kg, so you are already past 5% and nearly at 10%.
What 5, 10 and 15 percent look like
| Starting weight | 5% loss | 10% loss | 15% loss |
|---|---|---|---|
| 60 kg (132 lb) | 3.0 kg (6.6 lb) | 6.0 kg (13.2 lb) | 9.0 kg (19.8 lb) |
| 70 kg (154 lb) | 3.5 kg (7.7 lb) | 7.0 kg (15.4 lb) | 10.5 kg (23.1 lb) |
| 80 kg (176 lb) | 4.0 kg (8.8 lb) | 8.0 kg (17.6 lb) | 12.0 kg (26.5 lb) |
| 90 kg (198 lb) | 4.5 kg (9.9 lb) | 9.0 kg (19.8 lb) | 13.5 kg (29.8 lb) |
| 100 kg (220 lb) | 5.0 kg (11.0 lb) | 10.0 kg (22.0 lb) | 15.0 kg (33.1 lb) |
| 120 kg (265 lb) | 6.0 kg (13.2 lb) | 12.0 kg (26.5 lb) | 18.0 kg (39.7 lb) |
Why 5 to 10 percent is a meaningful goal
- Blood pressure and blood sugar. Modest weight loss improves both in many people with overweight or obesity.
- Diabetes prevention. In the US Diabetes Prevention Program (Knowler et al., N Engl J Med 2002;346:393–403), lifestyle changes that produced about 7 percent weight loss cut the progression to type 2 diabetes by 58 percent in high-risk adults.
- It is achievable. A 5 percent loss for a 90 kg person is 4.5 kg, a more realistic first target than a large number.
- More is not always better. Larger losses bring further benefits for some conditions but need more support and monitoring.
Keeping the weight off
Weight regain is common, so maintenance deserves as much planning as loss. Habits that keep weight steady, such as regular activity, consistent eating patterns and regular weighing, matter more than short-term diets. To plan the next stage use the Weight Loss Calculator for a timeline, the Goal Weight Date Calculator for a calendar date, and the Calorie Deficit Calculator for a daily target. The BMI Calculator and Healthy Weight Range Calculator help you check whether your goal sits within a healthy range.
This page is for information only and is not medical or dietary advice. Speak to a doctor or registered dietitian before starting a weight-loss plan, especially if you have a medical condition, take medicines, are pregnant or have a history of disordered eating.
Sources
- Jensen MD, et al. 2013 AHA/ACC/TOS guideline for the management of overweight and obesity in adults. Circulation 2014;129(suppl 2):S102–S138.
- Knowler WC, et al. Reduction in the incidence of type 2 diabetes with lifestyle intervention or metformin. N Engl J Med 2002;346:393–403.
- US Centers for Disease Control and Prevention. Benefits of Healthy Weight.
Frequently asked questions
How do I calculate percent weight loss?
Subtract your current weight from your starting weight, divide by the starting weight and multiply by 100. Losing 8 kg from 90 kg is 8 ÷ 90 = 8.9 percent. Using the starting weight, not the current one, is the standard way to express the figure.
Why does the percentage matter?
Clinical guidelines express weight-loss targets in percentages because health benefits relate to the relative change. The American Heart Association, American College of Cardiology and The Obesity Society (Jensen et al., 2014) describe a loss of 5 to 10 percent of body weight as producing clinically meaningful improvements in blood pressure, blood sugar and lipids.
Is a 5 percent weight loss enough?
For many people with overweight or obesity, yes, it brings measurable benefit, and larger losses add more. Benefits vary by person and condition, so ask your clinician what is right for you.
What if I regain weight?
The percentage will fall, and the calculator shows a negative figure if you are above your starting weight. Regain is common and does not mean failure; plan for maintenance as part of the programme.
Can I use body fat percentage instead?
Body fat percentage describes composition, not weight change. For tracking fat, use the Body Fat Calculator; this page tracks body weight only.