How to Calculate Your Basal Metabolic Rate (BMR)

Whether your goal is to lose weight, build muscle, or simply maintain your current physique, you need to understand one foundational metric: your Basal Metabolic Rate (BMR).

BMR is the absolute bare minimum number of calories your body requires to stay alive and function if you were to rest in bed all day. It covers the energy needed for breathing, circulating blood, controlling body temperature, and brain function.

Why Does BMR Matter?

Many people make the mistake of guessing their daily caloric needs based on generic advice (like the standard "2,000 calories a day" metric). However, caloric needs are highly individual.

Your BMR accounts for roughly 60% to 75% of the total calories you burn every day. If you don't know your BMR, you don't know your baseline. Without a baseline, setting a caloric deficit for weight loss or a surplus for muscle gain is just a shot in the dark.

How is BMR Calculated?

The most widely used and accurate formula for estimating BMR is the Mifflin-St Jeor Equation. It takes into account your gender, weight, height, and age.

For Men: BMR = (10 × weight in kg) + (6.25 × height in cm) - (5 × age in years) + 5

For Women: BMR = (10 × weight in kg) + (6.25 × height in cm) - (5 × age in years) - 161

As you can see, BMR decreases with age (as muscle mass naturally decreases), and increases with height and weight.

Total Daily Energy Expenditure (TDEE)

Your BMR is just the starting point. Because you don't stay in bed all day, you need to multiply your BMR by an "Activity Multiplier" to find your Total Daily Energy Expenditure (TDEE).

• Sedentary (office job): BMR × 1.2
• Lightly Active (exercise 1-3 days/week): BMR × 1.375
• Moderately Active (exercise 3-5 days/week): BMR × 1.55
• Very Active (hard exercise 6-7 days/week): BMR × 1.725
• Extra Active (physical job & hard training): BMR × 1.9

Your TDEE is the actual number of calories you burn in a typical day. To lose weight, you eat less than your TDEE. To gain weight, you eat more.

Finding Your Exact Numbers

Calculating your BMR and applying activity multipliers manually can be tedious, especially since you have to convert pounds and inches into kilograms and centimeters first.

To get your exact baseline instantly, use our free BMR Calculator. Once you have your baseline, you can easily plan your meals and take control of your health journey!