BMR Calculator
Basal Metabolic Rate — calories your body burns at rest
What is the BMR Calculator?
BMR stands for Basal Metabolic Rate, which is the number of calories your body burns just to stay alive. Not counting exercise, not counting walking to the kitchen. Just breathing, circulating blood, maintaining body temperature. It's the floor of your calorie needs. Knowing your BMR matters if you're tracking calories, setting a weight loss target, or trying to understand why the same diet affects different people so differently. CalciHub's BMR calculator uses two leading equations so you can compare results and get a more reliable estimate.
How Does It Work?
CalciHub calculates BMR (Basal Metabolic Rate) using both the Mifflin-St Jeor and Harris-Benedict equations.
Mifflin-St Jeor (more accurate for most people): Men: BMR = (10 × weight kg) + (6.25 × height cm) − (5 × age) + 5 Women: BMR = (10 × weight kg) + (6.25 × height cm) − (5 × age) − 161
Harris-Benedict (older but widely known): Men: BMR = 88.362 + (13.397 × weight kg) + (4.799 × height cm) − (5.677 × age) Women: BMR = 447.593 + (9.247 × weight kg) + (3.098 × height cm) − (4.330 × age)
weight = your body weight in kg height = your height in cm age = your age in years
Steps to Use CalciHub's BMR Calculator
Calculating your Basal Metabolic Rate (BMR) with CalciHub is quick and straightforward. Follow these simple steps:
1. Select your gender.
2. Enter your age, height, and weight.
3. Click Calculate.
4. View your BMR result from both equations.
BMR is your resting calorie burn; multiply it by an activity factor for your actual daily needs.
Tip: BMR alone doesn't tell you what to eat. You need to factor in activity level to get your actual daily calorie requirement. Use CalciHub's TDEE calculator for that next step.
A Quick Real Example
Mike is 29 years old, weighs 170 lbs (77.1 kg), and is 5'9" (175.3 cm). He enters his details into the BMR calculator.
Age: 29 | Weight: 170 lbs | Height: 5'9" | Gender: Male
Mifflin-St Jeor result: 1,823 calories/day Harris-Benedict result: 1,874 calories/day
Mike's BMR is roughly 1,820–1,870 calories per day. Even if he stayed in bed all day, his body would burn that much just to function. He uses this as the baseline before plugging his activity level into the TDEE calculator to find out what he should actually be eating.
Frequently Asked Questions
BMR (Basal Metabolic Rate) is measured under very strict conditions, completely at rest, in a fasted state, and in a controlled environment. RMR (Resting Metabolic Rate) is more practical and measured under normal resting conditions. They're close in value, and most calculators (including this one) use the terms interchangeably.