Weight Loss Percentage Calculator
Free weight loss percentage calculator: enter your starting and current weight to see the percentage of body weight lost, pounds or kilograms dropped, and progress toward the 5% and 10% health milestones.
Weight Loss Percentage Calculator
Units
Switching units relabels the fields only. Keep all weights in the same unit.
Your weights
Your baseline body weight at the start.
Your weight today.
Presets set a goal weight at a 5% or 10% loss from your starting weight.
Progress to your goal
For information only, not medical advice. Body weight shifts day to day with water, food, and hormones. Talk to your doctor or a registered dietitian before starting a weight-loss plan, especially if you are pregnant, nursing, under 18, or managing a medical condition.
How to calculate your weight loss percentage
The formula is short: weight loss percentage = (starting weight − current weight) ÷ starting weight × 100. Take the pounds or kilograms you have dropped, divide by the weight you started at, and multiply by 100. Because the units appear on both the top and bottom of the division, they cancel out, so the result is identical whether you measure in lbs or kg.
A worked example: you start at 200 lbs and drop to 180 lbs. That is (200 − 180) ÷ 200 × 100 = 10%. Now compare that to someone who started at 280 lbs and also lost 20 lbs. They are only at about 7.1%. Same 20 lbs on the scale, very different share of body weight. That is why percentage is a fairer progress metric than raw pounds across different body sizes, and why it maps cleanly onto the clinical milestones below.
What 5% and 10% weight loss actually means for your health
The research keeps landing on 5% of starting body weight as the point where real health changes kick in. At that level, studies report better insulin sensitivity, lower blood pressure, and improved triglycerides and cholesterol. A 5% loss over roughly six months is the minimum benefit threshold the NIH cites, and it is the bar the FDA uses when it decides whether an anti-obesity medication actually works.
Push into the 5 to 10% range and those gains grow: bigger drops in blood sugar and blood lipids, fewer risk factors for type 2 diabetes and heart disease, and less strain on the joints. For a 200 lb person, 5% is 10 lbs and 10% is 20 lbs, both within reach on a structured plan. This calculator shows how far you are from each milestone, so you can aim for the number that carries real clinical weight.
Setting a realistic weight loss pace
A pace you can keep up is roughly 0.5 to 1% of body weight per week, which works out to the familiar 1 to 2 lbs a week for most people. Over a few weeks that adds up fast: at 1 to 2 lbs weekly, ten weeks puts you near 10 to 20 lbs, often right in the 5 to 10% milestone range. Crash plans that promise much faster loss tend to burn muscle, stall your metabolism, and bounce back the moment you eat normally again.
Enter a goal weight above and the calculator shows your progress toward it, how much is left, and how ambitious the goal is as a percentage of your starting weight. Pair that with the calorie deficit calculator to set a daily intake, or check the BMI calculator and body recomposition calculator for more context on where you are starting from.
Tracking weight loss across a 75-day challenge
Weigh-ins are a built-in measurement task in several Reset75 templates, including 75 Tough, 75 Soft, 75 Hotter, Glow Within, and the 30-Day Kickstart. The app charts your numeric trend over time and can overlay a weight-loss line on your timelapse video, so the change is easy to see. The workflow is simple: log each weigh-in, run your latest number through this calculator to turn it into a percentage milestone, then keep your streak in the app.
If you want a free way to log it, Reset75 handles checklists, photos, and stats with no account required. To estimate how realistic your overall target is before you start, try the challenge success calculator, and use the macro calculator to dial in nutrition once your pace is set. For context, the original 75 Hard program created by Andy Frisella does not include weigh-ins, which is part of why a flexible tracker helps you measure progress your own way.
Frequently Asked Questions
Common questions about weight loss percentage calculator
How do you calculate weight loss percentage?
Subtract your current weight from your starting weight, divide by your starting weight, then multiply by 100. The formula is (starting weight − current weight) ÷ starting weight × 100. For example, going from 200 lbs to 180 lbs is (200 − 180) ÷ 200 × 100 = 10%. The units cancel out, so it works the same in pounds or kilograms.
What is a good weight loss percentage per week?
Most health authorities point to roughly 0.5 to 1% of body weight per week, which lines up with the common 1 to 2 lbs per week guideline. For a 200 lb person that is about 1 to 2 lbs weekly. Faster loss tends to come with more muscle loss and is harder to keep off. The calorie deficit calculator can help you set a sustainable pace.
Is losing 5% of your body weight significant?
Yes. A 5% loss of starting body weight is the clinical threshold linked to better blood pressure, blood sugar, triglycerides, and cholesterol. It is the minimum bar the NIH cites for a meaningful health benefit, and the level the FDA uses when it evaluates anti-obesity drugs. For a 200 lb person that works out to just 10 lbs.
What are the health benefits of losing 10% of your body weight?
A 10% loss builds on the 5% benefits, with bigger improvements in insulin sensitivity, blood lipids, blood pressure, and joint load, plus lower risk factors for type 2 diabetes and heart disease. The 5 to 10% range is where most of the heart-and-metabolism gains show up in the research.
Why use weight loss percentage instead of pounds or kilograms lost?
Percentage adjusts for body size, so it is a fairer comparison between people. Losing 15 lbs means something very different for a 130 lb person than for a 280 lb person. Percentage also lines up with the clinical 5% and 10% milestones that doctors use, which raw pounds do not.
How much weight loss is healthy over a 75-day challenge?
At a steady 1 to 2 lbs per week, a 75-day challenge (about 10.7 weeks) supports roughly 10 to 21 lbs of loss, which for most people lands in the 5 to 10% range. Treat that as a guide, not a target: body composition, water, and starting weight all shift the number. Slower and consistent beats crash dieting.
Does this calculator work in both pounds and kilograms?
Yes. Use the units toggle to switch between lbs and kg. The percentage formula is unit-independent, so the result is identical in either system. Switching units relabels the fields only and does not auto-convert the numbers you have entered, so keep all three inputs in the same unit.
How do I track my weight loss percentage during a 75-day or 75 Soft challenge?
Log a weigh-in on the same day each week, then run the two numbers through this calculator to convert pounds or kilograms into a percentage milestone. The free Reset75 app has a built-in weigh-in task in templates like 75 Soft and 75 Tough, charts the numeric trend, and can overlay a weight line on your timelapse. The weight tracker is the direct companion for logging each entry.