How to calculate your weight loss as a percentage

There are many reasons why a person may wish to lose weight. Having overweight or obesity increases the risk of a number of chronic health conditions, like type 2 diabetes, heart disease, and cancer. 

If you’re aiming to achieve a moderate weight, it’s important to lose weight in a controlled and healthy way. 

Below, we’ll look at three ways to calculate your weight loss as a percentage, including our handy weight loss percentage calculator.

We'll also look at how to lose weight safely, and we’ll consider other ways to track your weight loss and improve your health.

Ways to calculate weight loss as a percentage

Calculating your weight loss as a percentage may be a healthier and more sustainable approach than counting pounds or kilograms. That’s because this method tells you how much you’ve lost as a proportion of your starting weight, which is unique to you.

There are several different ways to calculate weight loss as a percentage.

1. Use our online body weight percentage calculator

The ZOE body weight calculator is the simplest and easiest way to work out how your body weight percentage has changed.

Just enter your starting weight and current weight, choose pounds or kilograms, and click the “Calculate” button to see the change in your body weight as a percentage:

What is your weight loss percentage?


2. Use this simple weight loss percentage equation

If you prefer to calculate your weight loss percentage yourself — or just want to understand how the calculation works — divide the amount of weight lost in pounds or kilograms by your starting weight in the same units, then multiply that by 100.

Here’s an example: 

  • 10 pounds / 180 pounds x 100 = 5.5% of starting body weight lost

A person started out weighing 180 pounds and has lost 10 pounds. This calculation shows that they have lost 5.5% of their body weight.  

3. Calculate weight loss as a percentage in a spreadsheet

Recording your weight loss percentage on a weekly basis in a spreadsheet, such as Microsoft Excel or Google Sheets, means you can track your progress. 

It’s best to work with a healthcare professional, who can advise on weight loss goals to achieve a moderate weight and who can monitor achievements.

Losing weight takes time, and you may see short-term ups and downs in the process. Keeping track of your weight loss percentage during this time in a spreadsheet can help you understand how your weight loss is progressing. 

There is no need to calculate your weight loss percentage every day. This may encourage obsessive behavior around weight loss. 

How to lose weight safely and improve health

When it comes to weight loss, there’s no “one-size-fits-all” solution. At ZOE, we believe everyone is different and that the first step toward improving your health — including your weight — is to discover how your body works. 

The ZOE at-home test kit analyzes how your body responds to the foods that you eat, giving you unique insights into your blood sugar and blood fat responses, along with your gut microbiome. Our program can help to boost energy, manage your hunger and weight, and help you reach your best health naturally. 

ZOE customers who closely followed their personalized nutrition plan lost an average of 9.4 pounds after 3 months. Around 80% didn’t feel hungry and said that they had more energy after their meals. 

However, not everyone needs to lose weight to improve their health. There is no need to lose weight if you have a moderate weight or if you are underweight. 

Your BMI can give you an indication of whether your weight is within a healthy range. You can calculate your BMI using the CDC adult BMI calculator. Here are the BMI ranges from the CDC:

  • BMI less than 18.5: underweight

  • BMI between 18.5 to 24.9: moderate weight

  • BMI between 25.0 to 29.9: overweight

  • BMI 30.0 or higher: obesity

If you do intend to lose weight, it’s important to do so safely. 

Weight control supplements that are used for rapid weight loss can have harmful side-effects and are not effective long-term.

What is a healthy weight loss percentage?

Overweight and obesity put you at greater risk of health conditions like type 2 diabetes, stroke, mental health conditions, and many types of cancer. 

Having more fat around the belly is a major risk factor for heart disease, metabolic health conditions, and cancer. Meanwhile, weight loss among people with obesity has been linked to a reduced risk of developing type 2 diabetes, heart disease, asthma, and chronic kidney disease.

According to the CDC, even a modest weight loss of 5–10% of your total body weight can be good for your health and lead to benefits, such as lower blood pressure, cholesterol, and blood sugar. 

They recommend aiming to lose 1–2 pounds per week. This approach, they say, is more likely to lead to success than trying to lose weight quickly. How much of your body weight percentage this is equal to depends on your current weight.

Losing weight gradually is more sustainable and healthier than “crash” dieting. That’s because crash dieting slows down your metabolism more than gradual weight loss. This means that your body gets used to burning fewer calories

This reduction in your metabolic rate can last for years and can lead to you putting weight back on — in many cases, more weight than you actually lost. 

Are there better ways to track weight loss and improve your health?

How much does your weight really tell you? Everyone is different, and your healthy weight range will depend on factors like your age, sex, metabolism, and your activity levels. 

If you’re doing more exercise, you may be increasing your muscle mass. Since muscle weighs more than fat, your weight could go up even if you’re losing fat. 

Using BMI to see whether your weight is in a healthy range is a starting point, but it doesn’t take your unique physiology and lifestyle into account. There are other ways of looking at your weight and health, however. 

More practical ways to track improvements in your health include:

  • measuring how much your strength has increased if you’ve been exercising 

  • checking how clothes fit you (perhaps you’ve changed the notch on your belt) 

  • thinking about whether you feel fitter or have more energy

  • looking at how much you’ve improved your diet

The ZOE program gives you scores for your meals based on how well they work for your unique body and metabolism. This can help you improve your diet and find the foods that are best for your body. 


Calculating your weight loss as a percentage may help you to lose weight in a more controlled way than simply looking at pounds or kilograms because it tells you how much you’ve lost as a proportion of your original weight. 

The simplest and easiest way to do this is using ZOE’s weight loss percentage calculator.

Increased belly fat is linked to a number of serious diseases, and people who have obesity can reduce the risk of getting these by losing weight. However, there is no need to lose weight if you are within a healthy range. If you are planning to lose weight, you should do it gradually and safely.

“Crash” dieting based on calorie counting is not a sustainable solution and can reduce your metabolic rate and actually lead to increased weight in the long-term.

Because muscle weighs more than fat, weight shouldn’t be your only focus when you’re aiming to improve your health. Look at other measures, such as increases in strength, fitness, and energy, or changes to how your clothes fit.

There’s no successful “one-size-fits-all” approach to weight loss. By helping you to understand how your body responds to different foods, the ZOE program can help to boost your energy, manage your hunger and weight, and improve your health naturally. 

Take our free quiz to learn how you can start eating the best foods for your unique body.


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Metabolically healthy obesity redefined. JAMA Network Open. (2021).

Sex differences in body composition and association with cardiometabolic risk. Biology of Sex Differences. (2018).

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Unhealthy weight control practices: Culprits and clinical recommendations. Clinical Medicine Insights: Endocrinology and Diabetes. (2015).

Weight loss and risk reduction of obesity-related outcomes in 0.5 million people: evidence from a UK primary care database. International Journal of Obesity. (2021).