Weight Loss Percentage Calculator
Not sure how to calculate your weight loss percentage? Or are you simply wondering if this new Mochi weight loss method brought the result you hoped for? This calculator has got you covered! Our body percent weight loss calculator will help you determine the percentage of weight loss in seconds. No need to memorize the weight loss formula — enter your numbers and let the calculator do the work!
Why weight loss stalls?
Weight loss isn’t just about willpower; it’s often about biology. Hormones, stress, sleep, and past diets can slow things down. If your body feels unsafe (too little food, too much stress), it may hold on to fat. You might eat “perfectly” and still not see results. It's frustrating but normal. It doesn’t mean you’re failing. Weight loss takes time, and progress doesn’t always show up on the scale right away. Be patient with your body. It’s working harder than you think.
Why you might have trouble losing weight?
Many people start too fast — skipping meals, cutting carbs, or overexercising. These “quick fixes” often backfire. You might lose weight fast but gain it back just as quickly. Focusing only on the scale is another trap.
Weight can shift daily due to water or hormones. And trendy diets? They rarely work long-term. Instead, build small habits you can stick with:
- Regular meals;
- Movement you enjoy;
- Getting enough sleep; and
- Not calculating your weight loss obsessively — yep, don't fixate on tracking it 😉
If you're not sure where you stand, we recommend you check our BMI calculator to see if there is even weight to worry about.
Real change happens slowly. And that’s okay. Slow progress is sustainable progress.
How to calculate weight loss percentage — Weight loss formula
To calculate how much weight you've lost as a percentage of your starting weight, use the following formula:
(past weight − current weight) / past weight × 100% = weight loss percentage
The ratio is calculated by subtracting your current weight from your past weight, dividing it by the past weight, and multiplying by a hundred. Let’s say your past weight was 200 lb, and your current weight is 180 lb:
(200 − 180) / 200 × 100% = 10%
That means you’ve lost 10% of your body weight, which equals 20 lbs.
The calculator also shows the units of weight you lost in the process by simply subtracting your current weight from your past weight:
past weight − current weight = weight loss
Want to know the ideal weight for your height and sex? Our ideal weight calculator can help you find it easily.
How to use weight loss percentage calculator
Using our body percent weight loss calculator is super quick — just enter your numbers, and we’ll do the math for you. See how to figure out the percentage of weight loss in seconds:
- Type in your past weight.
- Enter your current weight.
- The calculator instantly calculates your weight loss percentage and total weight loss.
But there's more!
The calculator works in different directions. No matter which two values you enter, the calculator will automatically figure out the others. For example, if you know your current weight and the amount of weight you'd like to lose, you can type in those variables, and it will show your past weight and your total weight loss percentage.
Weight says very little about your overall health
Losing weight, even by a small percentage, can lower your risk of heart disease, diabetes, or high blood pressure. But health isn't just about the scale. How you feel, move, and live matters more.
Calculating your weight loss can unravel how your metabolism is working — but it's not the full picture.
A faster metabolism burns more energy, but things like age, hormones, stress, and muscle mass affect it, too. If you're losing weight slowly and steadily, that often means your body is adjusting in a healthy way. If progress stalls, it doesn't always mean your metabolism is "broken"; it might just be time to rest, eat more consistently, or build more muscle. Metabolism isn't fixed; you can support it with smart habits.
FAQs
What is a healthy weight loss percentage?
There is no one-size-fits-all. It really depends on multiple factors. It's believed that for people with obesity, it's beneficial to lose 5%-10% of their total weight. However, it's best to consult with a professional about your individual case.
How can I calculate weight loss percentage?
To figure out the percentage of weight loss:
- Note your past weight and the current weight.
- Subtract your current weight from your past weight.
- Divide the outcome by your past weight.
- Multiply the result by 100 to express it as a weight loss percentage.
The corresponding formula is as follows:
(past weight − current weight) / past weight × 100%
What’s the weight loss percentage for 190 lb starting weight and 15 lb lost?
7.89%. Using the formula (past weight - current weight) / past weight × 100%, divide the amount of weight lost by the starting weight and multiply by 100:
15 / 190 × 100% = 7.89%
So, losing 15 lb from a starting weight of 190 lb results in a 7.89% total weight loss. This falls within the commonly recommended range of 5%-10% for healthy weight loss.
What is a good percentage of weight loss?
Around 0.5% to 1.0% of your body weight per week. The following values are considered to be a good percentage of weight loss. For example, that’s about 0.3-0.6 kg (0.7-1.3 lbs) per week for a woman and 0.4-0.8 kg (0.9-1.8 lbs) for a man.
How can I track progress without obsessing over numbers?
The scale is just one part of the story. Track how your clothes fit, your energy levels, or your strength. Take monthly progress photos or notice changes in sleep, mood, or workouts. Write down small wins like cooking at home or walking more. Progress isn’t always visible right away — and that’s okay. Focus on habits and building a lifestyle that supports a healthy body.