Basal Metabolic Rate Calculator

Your Basal Metabolic Rate (BMR) is the number of calories your body burns each day just to stay alive at complete rest, before you add in any movement, exercise or digestion. It covers the energy your organs need to keep functioning: roughly 70 percent goes to basal processes inside your organs (the liver is the biggest user, ahead of the brain), about 20 percent goes to physical activity, and the remaining 10 percent goes to keeping your body warm. This calculator works out your BMR using the Mifflin-St Jeor formula, one of the most widely used equations for estimating resting energy needs. Enter your gender, height, weight and age, choosing whichever side suits you: the metric panel takes centimetres and kilograms, while the imperial panel takes feet and inches and pounds. Click Calculate and the tool returns your BMR Rate in kilocalories per day, the baseline number of calories you would burn if you did nothing but rest for 24 hours. This is not your total daily calorie need; it is the starting point before activity is added, which is where a TDEE calculator comes in. Knowing your BMR is useful for setting weight loss, maintenance or muscle gain targets, since a sensible calorie target should be built up from this baseline rather than guessed. Treat the result as an indicative guide rather than an exact medical measurement.

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