What's your Resting Metabolic Rate?

Our accurate RMR Calculator will work out your Resting Metabolic Rate. That's how many calories your body needs to stay alive. RMR covers all the basic bodily functions including keeping your heart beating, your lungs breathing, your brain functioning, and all the other tasks your body does to maintain life.

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Accurate RMR Calculator

Our RMR Calculator is 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.

Atlas Says: RMR 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 RMR.


Your RMR (Resting Metabolic Rate) and TDEE (Total Daily Energy Expenditure), differ slightly in that your TDEE calculation is your RMR 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 RMR?

There are two formula's we use in this Resting 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 RMR 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) ) )

Atlas Says: These formulas give an estimation of the number of calories your body burns staying alive. It's best to say that there is a margin of error of 10%, so regularly check and tweak to provide better results.