BMR Calculator

We’re re-coding our BMR Calculator.
But this is a great one to use from the awesome folks over at

What is BMR?

The rate at which energy (calories) is used for the essential life functions is called Basal Metabolic Rate (BMR). Basal metabolism includes most of the involuntary things the human body does to support life – such as breathing, blood circulation, body temperature regulation, nervous system operations, etc., but not the extra energy needed for any additional physical activity such as gym exercise.

In other words, if you laid in bed all day doing nothing else, then you would need to eat at least the number of calories roughly equal to your BMR in order to maintain your normal body functions.

Basal metabolism consumes from 60 to 70% of body’s total daily calories expenditure.


What is RMR?

Resting Metabolic Rate (RMR) is equivalent to BMR but is measured under less strict conditions. BMR usually assumes special lab conditions where even the room temperature has to be exact. RMR is the BMR value adjusted for the regular life environment.

RMR values are about 15% higher than the BMR values.

In your diet calculations, you can safely use RMR instead of the scientifically precise BMR.


What is TDEE?

Your TDEE is comprised of your basal metabolic rate (BMR) plus additional energy burned through physical activity and the food you eat.


TDEE or Total Daily Energy Expenditure is a compilation of your:


– TEF – the energy burned through food absorption (TEF – The thermic effect of food – when we eat it takes energy to absorb and utilize this food and a rough approximation is it costs around 10% depending on the macronutrient profile in your diet i.e fats,carbs,protein etc)

– And your physical activity.


To calculate your TDEE (Total Daily Energy Expenditure) you’d multiply your BMR (which you have from the above calculator) by activity multipliers:

We can use an equation with activity multipliers to calculate our TDEE – one of the best is the Katch-McArdle equation.

*Note:  these multipliers are said to OVER estimate your energy expenditure so by modifying them slightly as listed below it will allow you to not be stuck in too small a calorie deficit to see results.

And these calculations are not 100% accurate but simply a valuable way to create a baseline that you can deduct calories from to put yourself into a daily calorie deficit (negative energy balance to lose weight and body fat)


The modified Katch-McArdle equation (thanks to muscleforlife) 

1.1 = sedentary (little or no exercise)

1.2 = light activity (light exercise/sports 1 to 3 days per week)

1.35 = moderate activity (moderate exercise/sports 3 to 5 days per week)

1.45 = very active (hard exercise/sports 6 to 7 days per week)

1.6 to 1.8 = extra active (very hard exercise/sports 6 to 7 days per week and physical job)


Male subject / very active): BMR of 2000 calories

2000 X 1.45 = TDEE of 2900 calories daily as a baseline.

Then deduct 20-25% from this to give yourself a daily deficit:

2900 – 580 (20%) = 2320 calories per day to be consumed

*Adjust and play around with this formula and see what works best for you.



Hope this is of use and helps you get your daily calories dialed in.





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