Weight Loss Percentage Calculator: What Percent Have You Lost?
Losing 10 lb means something very different at 150 lb than it does at 300 lb. Percentage is how doctors, trainers and clinical trials actually measure progress. Works in kg, pounds or stones.
The 30-second answer
To find what percentage of your body weight you have lost, subtract your current weight from your starting weight, divide by your starting weight, then multiply by 100. Going from 220 lb to 195 lb is 25 lb lost, and 25 ÷ 220 × 100 = 11.4 percent. Losing 5 percent is clinically meaningful, and 10 percent is the target most medical guidelines aim for.
5%
Clinically meaningful
Health markers move
10%
Excellent
Guideline target
0.5 to 1%
Healthy pace
Per week
kg · lb · st
Any unit
Percentage is a ratio
100%
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How do I know what percentage of my body weight I have lost?
You need two numbers and nothing else: the weight you started at, and the weight you are now. Subtract the second from the first to get the weight you have lost, divide that by your starting weight, and multiply by 100. That single number tells you more about your progress than the pounds ever will, because it is scaled to the body you began with.
The one rule that trips people up: always use your original starting weight. If you keep resetting it to last month's number, your percentage will hover near zero forever and hide months of real progress.
How we calculate your progress
The whole calculation, one step at a time. It works identically in kg, lb or stone, as long as both weights use the same unit.
- 1Starting weight220 lb
- 2Current weight195 lb
- 3Subtract25 lb lost
- 4Divide by start25 ÷ 220
- 5Times 10011.4%
The formula
((Start - Current) ÷ Start) × 100
What does your percentage actually mean?
Weight loss percentage is not a vanity metric. Each milestone maps to a specific, measurable change in your health, which is why clinical trials report results as a percentage of starting body weight rather than in pounds.
Weight loss percentage chart
What each milestone actually does for your health. Percentages are of your starting weight, not your current weight.
- 5%
Clinically meaningful
About 11 lb if you started at 220 lb
Blood pressure, blood sugar and triglycerides start to improve. This is the point doctors call a clinically significant weight loss.
- 10%
Excellent
About 22 lb if you started at 220 lb
Meaningful drop in type 2 diabetes risk, better cholesterol, and improvements in sleep apnoea. This is the target most clinical guidelines aim for.
- 15%
Major improvement
About 33 lb if you started at 220 lb
Large improvements in body composition and metabolic health. Type 2 diabetes remission becomes realistic for some people.
- 20%
Obesity treatment target
About 44 lb if you started at 220 lb
The level newer obesity treatments aim for. Substantial change in long-term disease risk, but it needs medical support to reach and hold.
Health benefits follow CDC and NIH guidance. Individual results vary.
Did you lose fat, water, or muscle?
This is the question the scale can never answer, and it is the one that decides whether your results last. Take a real example: someone at 98 kg who has lost 8 kg in 7 weeks. That is 8.2 percent, at a pace of about 1.2 percent a week, which is on the fast side. At that speed a meaningful share of those 8 kg is water and muscle, not fat.
Water comes off first and fast, because your body stores roughly three grams of water with every gram of glycogen it burns through. That is why week one on any diet looks miraculous and week three looks like a stall. Nothing has gone wrong. The water simply ran out.
Did you lose fat, water, or muscle?
The scale shows one number. It never says what that number was made of. How fast you lose changes the answer.
Fat
13.5 lb
Water
2.7 lb
Muscle
1.8 lb
Illustrative split of an 18 lb loss. Losing quickly pulls far more from water and muscle. Enough protein and resistance training push the loss toward fat, which is the part you actually want gone.
To find out where your own loss is coming from, run the GLP-1 Body Composition Tracker to see if you are losing fat or muscle, then set a protein target with the lean body mass calculator.
How much weight should you lose per week?
Judge your pace as a percentage of your body weight, not in pounds. Two pounds a week is gentle at 300 lb and aggressive at 130 lb. The safe, sustainable range is 0.5 to 1 percent of body weight per week, which is roughly what the CDC describes as steady, gradual weight loss.
How fast should you lose weight?
The safe, sustainable range is about 0.5 to 1 percent of your body weight a week. Faster than that and the loss starts coming from muscle.
Too slow
Under 0.25%
Healthy
0.5 to 1%
Aggressive
1 to 1.5%
Too fast
Over 1.5%
Example: at 200 lb, a healthy week is roughly 1 to 2 lb. Losing 4 lb a week at that size is over 1.5 percent, which is the zone where muscle loss climbs sharply.
Real weight loss examples
The same amount of weight is a very different percentage depending on where you started. These worked examples show exactly how the maths lands.
| Started at | Now | Lost | Percentage | What it means |
|---|---|---|---|---|
| 220 lb | 195 lb | 25 lb | 11.4% | A strong result. Past the 10 percent milestone. |
| 98 kg | 90 kg | 8 kg | 8.2% | Approaching the 10 percent milestone. |
| 100 kg | 89 kg | 11 kg | 11.0% | Started at 100 kg, so 11 kg is 11 percent. |
| 15 st 0 lb | 13 st 8 lb | 1 st 6 lb | 9.5% | Stones work too, once converted to pounds. |
| 150 lb | 135 lb | 15 lb | 10.0% | 10 percent of 150 lb is 15 lb. |
Swipe the table sideways to see every column.
The questions people actually ask
I lost 8 kg. Is that good?
It depends completely on where you started. Eight kilograms from 98 kg is 8.2 percent, a strong result closing in on the 10 percent milestone. The same 8 kg from 150 kg is 5.3 percent, which is still clinically meaningful but a smaller share of your body. This is precisely why percentage is the fairer measure.
What percentage is 10 pounds?
Divide 10 by your starting weight. From 150 lb it is 6.7 percent. From 200 lb it is 5 percent. From 250 lb it is 4 percent. Ten pounds is real progress at any size, but its percentage shrinks as your starting weight grows, which is why the scale alone can feel discouraging for heavier people.
Is losing 15 percent of your body weight too fast?
The total is not the issue, the timeframe is. Fifteen percent over six to twelve months is an excellent, well-paced result that many clinical programmes aim for. Fifteen percent in six weeks is far too fast, and a large share of it will be muscle and water. Always judge the rate per week, not the headline number.
Why is my weight loss percentage lower than I expected?
Two common reasons. First, percentage is measured against your starting weight, which is a big number, so 10 lb from 250 lb is only 4 percent. Second, and more damaging, you may have updated your starting weight along the way. Doing that erases your own progress. Lock in the original number and never change it.
What is 5 percent of my body weight?
Multiply your starting weight by 0.05. At 150 lb it is 7.5 lb. At 200 lb it is 10 lb. At 100 kg it is 5 kg. That 5 percent is the threshold where blood pressure, blood sugar and cholesterol begin measurably improving, which is why doctors treat it as the first real milestone.
What percent weight loss is noticeable to other people?
Studies of facial perception suggest change becomes visible to strangers at roughly 3 to 4 percent of body weight, and is clearly noticeable by around 5 to 10 percent. Height, where you store fat, and what you wear all move that line, so the point at which people start commenting varies a lot.
How do I calculate weight loss percentage in kg or stones?
Exactly the same way. Percentage is a ratio, so the unit cancels out entirely. A 10 percent loss is 10 percent in kilograms, pounds or stones. The only requirement is that your starting weight and your current weight are both expressed in the same unit. If you work in stones and pounds, convert both figures to pounds first.
What about percent weight loss in newborns?
This is a completely different, clinical measurement, and this calculator is not the right tool for it. Most newborns lose 5 to 7 percent of their birth weight in the first few days of life, which is normal. A loss of more than 10 percent is a recognised medical concern and needs assessment by a paediatrician or lactation consultant, not a general calculator. If you are tracking an infant, please speak to a healthcare professional.
Weight loss percentage on a GLP-1
If you are on Ozempic, Wegovy, Mounjaro or Zepbound, these are the averages people tend to hit. Use them as a gut check, not a scoreboard.
Semaglutide (Wegovy)
- Month 2about 2 to 4%
- Month 3about 4 to 6%
- Month 6around 11%
Tirzepatide (Zepbound / Mounjaro)
- By month 3about 5 to 8%
- By month 6about 10 to 15%
- Notemore than semaglutide
A falling percentage is only half the story. Up to 40 percent of GLP-1 weight loss can be muscle if you do not protect it. Check your split with the GLP-1 Body Composition Tracker to see if you are losing fat or muscle.
What this number cannot tell you
- It measures total body weight, which includes fat, water, glycogen and muscle. It cannot separate them.
- Day-to-day weight swings of 2 to 4 lb are normal from water, salt and food. Weigh weekly under the same conditions and trust the trend.
- A falling percentage is not automatically good. Losing quickly, or losing while under-eating protein, can mean losing muscle.
- It says nothing about where you carry weight. Waist circumference is a better marker of visceral fat risk.
- It is not designed for infants, pregnancy, or clinical fluid-loss assessment.
How we calculated this
We use the standard percentage change formula, ((starting weight minus current weight) divided by starting weight) times 100, applied to your original starting weight. Weekly pace is expressed as a percentage of body weight per week, and the healthy range of 0.5 to 1 percent follows CDC guidance on gradual, steady weight loss. Milestone health benefits at 5, 10 and 15 percent follow CDC and NIH guidance. We do not store your weights, and nothing leaves your browser.
Make the weight you lose the weight that stays off
A percentage is a snapshot. What protects your results is logging your weight and protein consistently, so a fast week shows up as something to check rather than something to celebrate. Calqulate Vitals keeps it all on one timeline for free, and Premium adds your projected goal date and the fat vs muscle trend.
- Log a weight in seconds, from any device
- Everything you log on one timeline
- Find out how much protein is really in your meal
- Goal date and fat vs muscle trend (Premium)
Sources and references
This page is built from public clinical guidance and peer-reviewed research. Always confirm decisions with a licensed clinician.
Medical disclaimer: This calculator is for educational purposes only and does not diagnose or treat any condition. Always consult a qualified healthcare provider before starting a weight loss programme, especially if you have underlying health conditions, are pregnant, or take medication.
Common weight loss percentage questions
Frequently Asked Questions
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July 24, 2026
Dr. Jaydeep Sanghani
Meet Akabari
Dr. Jaydeep Sanghani
MBBS, MD, DNB(Anaesth.), PDCC(CCM), DrNB(CCM)
AIIMS Bhubaneswar · AIIMS Rishikesh
Critical care specialist and anesthesiologist with advanced training from AIIMS. Reviews health calculators at Calqulate to ensure medical accuracy and evidence-based standards.
About the authors
Meet Akabari
·Co-Founder, Calqulate.net