Resting Metabolic Rate (RMR) Calculator
Calculate how many calories your body burns at complete rest.
Your Resting Metabolic Rate
This is the estimated number of calories your body burns daily if you do absolutely nothing (complete rest).
Estimated Total Daily Energy Expenditure (TDEE)
If you include light activity (Sedentary Office Job):
How to Calculate Resting Calorie Burn Rate
Understanding your Resting Metabolic Rate (RMR) is the foundational step in managing weight, whether your goal is fat loss, muscle gain, or maintenance. Your resting calorie burn rate represents the energy your body requires to perform basic life-sustaining functions such as breathing, circulating blood, and cell production, assuming you are at complete rest.
RMR vs. BMR: What is the Difference?
While often used interchangeably, there is a slight technical difference between Resting Metabolic Rate (RMR) and Basal Metabolic Rate (BMR):
- Basal Metabolic Rate (BMR): This is the absolute minimum number of calories needed for basic functions in a clinically controlled environment (often measured after 8 hours of sleep and fasting).
- Resting Metabolic Rate (RMR): This is the number of calories your body burns while at rest under less strict conditions. In practical terms for diet planning, the two figures are nearly identical.
The Calculation Formula
This calculator uses the Mifflin-St Jeor equation, which is widely considered by dietitians and health professionals to be the most accurate formula for estimating calorie needs in the general population.
The math behind the scenes involves converting your weight to kilograms and height to centimeters, then applying the following logic:
- Men: (10 × weight in kg) + (6.25 × height in cm) – (5 × age in years) + 5
- Women: (10 × weight in kg) + (6.25 × height in cm) – (5 × age in years) – 161
Example Calculation
Let's look at a realistic example to understand the output. Consider a 35-year-old female who is 5 feet 6 inches tall and weighs 150 lbs.
- Convert Weight: 150 lbs ÷ 2.205 = 68.04 kg
- Convert Height: 66 inches × 2.54 = 167.64 cm
- Apply Formula: (10 × 68.04) + (6.25 × 167.64) – (5 × 35) – 161
- Result: 680.4 + 1047.75 – 175 – 161 = 1,392 Calories/Day
This means if this individual stayed in bed all day, she would burn approximately 1,392 calories just to stay alive.
Factors That Influence Your Burn Rate
Your resting burn rate is not a static number. It is influenced by several factors, some of which you can control:
- Muscle Mass: Muscle tissue burns more calories at rest than fat tissue. Increasing muscle mass through resistance training raises your RMR.
- Age: As we age, our metabolic rate tends to decrease, largely due to a loss of muscle mass and hormonal changes.
- Body Size: Larger bodies have more metabolizing tissue and therefore a higher BMR/RMR.
- Genetics: Some individuals naturally have a faster or slower metabolism due to their genetic makeup.
From Resting to Total Burn (TDEE)
Remember that your RMR is only part of the equation. To find your maintenance calories (Total Daily Energy Expenditure or TDEE), you must account for your activity level. A sedentary person typically multiplies their RMR by 1.2, while a highly active athlete might multiply it by 1.7 or more.