BMR Calculator: Our Best, Most Accurate BMR Calculator [Free] (2024)

Table of Contents

BMR vs TDEE? What formulas do you use to work out BMR? BMR Calculations and why calculating BMR is important Why should you use our best, most accurate BMR Calculator for free? FAQs References

We think this is our best BMR Calculator ever. It may be the most accurate BMR Calculator with body fat online. It's designed to help you work out how many calories your body burns to maintain life, which includes all the basic bodily functions. It does not account for sleeping, moving, eating, exercising, and other activties you do. It's just the most basic level of life.

Try our Accurate TDEE Calculator to get your Total Daily Energy Expenditure.

Atlas Says: BMR is a great calculation when working out a minimum number of calories your body needs which is ideal for your fitness and nutrition plan. Never eat fewer calories than your BMR as it's the minimum for a healthy functioning body.

BMR vs TDEE?

Your BMR (Basal Metabolic Rate) and TDEE (Total Daily Energy Expenditure), differ slightly in that your TDEE calculation is your BMR plus all of your daily activities including sleeping, walking, working, exercising, eating, etc.

Atlas Says: Try our TDEE Calculator to discover how many calories you burn in a day.

What formulas do you use to work out BMR?

There are two formula's we use in this accurare Basal Metabolic Calculator, they are: Mifflin-St Jeor and Katch-McArdle. If you include body fat percentage then the calculator uses the accurate Katch-McArdle formula. However, if you do not add your body fat percentage, then the calculator falls back to using the Mifflin-St Jeor formula (which is still very accurate). This formula excludes the activity level factor usually included in the above formulas to provide an accurate BMR calculation.

Mifflin-St Jeor Formula

Male = ( 10 x Weight in KGs ) + ( 6.25 x Height in CMs ) - ( 5 x Age ) + 5
Female = ( 10 x Weight in KGs ) + ( 6.25 x Height in CMs ) - ( 5 x Age ) - 161

Katch-McArdle Formula

Male & Female = 370 + ( 21.6 x ( Weight in KGs - (Body Fat % x Weight in KGs) ) )

BMR Calculations and why calculating BMR is important

The single most important reason for calculating BMR is to do with accurately estimating how many calories your body requires depending on your own personal body composition - with the exclusion of your daily active levels.

Once you have this number, then you can use it as the backbone for your training and nutrition goals when you factor in your daily activity levels.

Calculating BMR for fat loss. If you are trying to reduce the amount of body fat then you will require a deficit against your BMR calculation. For the example of calculating BMR for fat loss, if your BMR is 2000 calories + daily activity level calories of 500, then a 10% calorie deficit will mean that you need to roughly eat 2250 calories a day to ensure you are in caloric deficit. The 10% deficit used here is a manageable deficit, a deficit of between 10% to 20% is recommended for reducing body fat - too many calories will also mean muscle loss.

Calculating BMR for muscle gain. Conversly if you are trying to gain muscle then you will require a calorie surplus against your BMR calculation. For the example of calculating BMR for muscle gain, if your BMR is 2000 calories + daily activity level calories of 500, then a 10% calorie surplus will mean that you need to roughly eat 2750 calories a day to ensure you are in caloric surplus. The 10% surplus used here is a manageable surplus, a surplus of between 10% to 20% is recommended for muscle gain- too many calories will also mean fat gain.

Please also note that these BMR calcualtion examples are when combining nutrition with resistance and cardio training for maximum benefit + don't forget your BMR does not include the calories you burn through your daily activity.

Atlas Says: BMR calulations are the backbone for fat loss, muscle gain, and weight maintenance. What is measured, can be improved.

Why should you use our best, most accurate BMR Calculator for free?

We have been working hard to bring you our best, most accurate BMR Calculator in this latest version of Atlas. Cue the sales pitch...but it's free.

It's really important that our BMR Calculator is not just accurate but also better than any other on the entire web. We may just have done exactly that!

Below are some great reasons we think you should use our BMR Calculator over any of those other inferior calculators online.

100% Completely Free - You heard it right, our BMR Calculator is completely free to use now and forever.

Absolutely No Sign Up Forms - We don't want your data. Not your email address, not your name, address, or even your credit card details.

Instant Online Body Insights - Unlike some of the other fitness calculators we show your results instantly online. Get instant access to your BMR Calculator results.

Accurate BMR Calculator - Because we think this is our best BMR Calculator it has to be super accurate, so we did just that and made it so.

Privacy Friendly - As we don't ask you to sign up or for any of your personal details, our tool is privacy friendly.

BMR Calculator: Our Best, Most Accurate BMR Calculator [Free] (2024)

FAQs

What is the most reliable BMR calculator? ›

Of these equations, the Mifflin-St Jeor Equation is considered the most accurate equation for calculating BMR with the exception that the Katch-McArdle Formula can be more accurate for people who are leaner and know their body fat percentage.

What is a good BMR for my age? ›

How to Calculate your ideal BMR?

Age	Male (calories per hour)	Female (calories per hour)
20–29	39.5	37.0
30–39	39.5	36.5
40–49	38.5	36.5
50–59	37.5	35.0

2 more rows

Jun 3, 2021

What is a good BMR for weight loss? ›

While a 1500 BMR for women and 2000 for men is believed to be fairly standard, it doesn't mean that is a good BMR number. That's because your BMR number is based upon your weight, height, sex, and age, the combination of those factors are unique to you alone.

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How to accurately calculate BMR? ›

Calculate Basal Metabolic Rate

Your basal metabolism rate is produced through the following basal metablic rate formula: Men: BMR = 88.362 + (13.397 x weight in kg) + (4.799 x height in cm) – (5.677 x age in years) Women: BMR = 447.593 + (9.247 x weight in kg) + (3.098 x height in cm) – (4.330 x age in years)

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Is your BMR higher if you are overweight? ›

If you have a slow metabolism or slow BMR, your body needs fewer calories to keep it going. A fast metabolism does not necessarily lead to thinness. In fact, studies show that people with overweight/obesity often have fast metabolisms. Their bodies need more energy to keep basic body functions going.

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Should you eat more than your BMR to lose weight? ›

If you've found your BMR and converted it to TDEE, you know what your body requires in a day to stay at its current weight. That's your starting point. You need to consume less than your TDEE if you want to achieve weight loss.

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How many calories should I eat if my BMR is 1500? ›

At a baseline, knowing your BMR provides a caloric goal your body needs to perform basic functions. For example, a BMR of 1,500 means you need to consume at least 1,500 calories to help your body work efficiently. This knowledge is important if you plan to gain, lose or remain the same weight.

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What is the ideal BMR for a woman? ›

The average BMR for women is around 1400 kcal and about 1700 kcal for men, she says. Even if you and your workout buddy are the same age, sex, height, weight, and body composition, you still can have different BMRs. Things totally out of your control, like genetics and even organ size, impact BMR.

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How can I lose weight if my BMR is 1400? ›

How Many Calories Should I Eat Daily to Lose Weight? For example, if your BMR is 1,400 (the average for American women) and you are moderately active, your AMR would be 2,170 (1,400 x 1.55). Since a pound of fat is equal to 3,500 calories, you would need to cut 500 calories per day to lose a pound per week.

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How do I adjust my BMR to lose weight? ›

To lose weight using your BMR:

The number should be somewhere between your BMR and the number of calories you need to maintain your current weight. As a guide, the average man needs about 2,500 calories and the average woman needs 2,000 calories a day to maintain their weight.

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What happens if I eat below my BMR? ›

In reality, your body responds to eating below your BMR the same way it responds to calorie restriction of any sort—it simply breaks down more body fat to keep your organs supplied with energy. Thus, there's nothing inherently bad or unhealthy about eating below your BMR.

Why is my BMR going down as I lose weight? ›

"Smaller bodies require less energy to function than a larger body-just like a small apartment requires less energy to heat than a larger house." You don't need as many calories to function at 150 pounds as you did at 200 pounds. Your BMR falls, or slows, with weight loss.

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How to boost up metabolism? ›

5 ways to boost metabolism

Exercise more. Add interval training to your cardio routine and burn more calories in less time. ...
Weight train. Add muscle mass to your body and you can burn more calories at rest. ...
Don't skip meals, especially breakfast. ...
Eat fat-burning foods. ...
Get a good night's sleep every night.

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How many calories do you burn in a day without exercise as a female? ›

How many calories do you naturally burn in a day? That depends on your age, sex, height, and weight. It can approximately range from 2,000 to 2,450 calories for men and 1,600-1,950 for women (not including calories burned from exercise).

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What does your metabolic age say about you? ›

If your metabolic age is lower than your actual age, it means your body is in good health. If your metabolic age is higher than your actual age, it may mean you have health problems or may need to change your eating and exercising habits.

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What is the most accurate way to test BMR? ›

The most accurate way to calculate your BMR is to get it tested at a lab. You'll breathe into a special mask called a calorimeter that covers your mouth and/or nose. The mask uses your breath rate to measure the calories you burn. You'll need to sleep at the lab overnight to get an accurate BMR measurement.

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What is the strongest predictor of BMR? ›

Fat-free mass is the best predictor of measured BMR.

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When to use Mifflin St. Jeor vs. Harris Benedict? ›

The most widely-used equation for estimating REE is the Harris–Benedict equation (HB) [6–7]. Following the recommendations of the American Dietetic Association (ADA) [8] the Mifflin–St Jeor (MSJ) equation is more reliable, especially in obesity [9].

Is Mifflin St. Jeor accurate? ›

The Mifflin-St Jeor equation is more likely than the other equations tested to estimate RMR to within 10% of that measured, but noteworthy errors and limitations exist when it is applied to individuals and possibly when it is generalized to certain age and ethnic groups.