BMR Calculator
BMR Calculator
Find your Basal Metabolic Rate using precision equations
Quick answer
A BMR calculator estimates the calories your body burns at complete rest. With the Mifflin-St Jeor equation, women use BMR = 10W + 6.25H − 5A − 161 and men use +5 instead of −161. For example, a 30-year-old woman who weighs 60 kg and is 165 cm tall has a BMR of about 1,320 kcal a day (1,384 kcal with the revised Harris-Benedict formula).
Our free BMR calculator works out your Basal Metabolic Rate with two trusted equations, Mifflin-St Jeor and the revised Harris-Benedict, so you can compare them side by side. Choose your sex, enter your age, weight and height, and the BMR calculator shows your resting calorie burn instantly.
Your BMR is the foundation of every diet and fitness plan. Once you know it, you can work out your total daily calories and set targets for losing, maintaining or gaining weight. Everything is calculated privately in your browser.
What Is BMR?
Basal Metabolic Rate (BMR) is the number of calories your body needs to stay alive while completely at rest: breathing, pumping blood, controlling body temperature and repairing cells. For most people, BMR makes up roughly 60 to 70% of the calories they burn in a day. Read more about basal metabolic rate.
Mifflin-St Jeor (men): 10W + 6.25H − 5A + 5
Mifflin-St Jeor (women): 10W + 6.25H − 5A − 161
Revised Harris-Benedict (men): 88.362 + 13.397W + 4.799H − 5.677A
Revised Harris-Benedict (women): 447.593 + 9.247W + 3.098H − 4.330A
W = weight in kg, H = height in cm, A = age in years
How to Use the BMR Calculator
Follow these four quick steps:
Step 1: Select Male or Female
Tap Male or Female. Men and women have different BMR equations because of typical differences in muscle mass.
Step 2: Enter Your Age, Weight and Height
Type your age in years, weight in kilograms and height in centimetres, for example 30, 60 and 165.
Step 3: Click Calculate BMR Value
Press Calculate BMR Value. The BMR calculator runs both equations at once.
Step 4: Read Your BMR Results
The main number is your Mifflin-St Jeor BMR, generally considered the most accurate for adults today. Below it you will see the Revised Harris-Benedict result and the minimum daily calories your body needs at rest.
BMR Calculation Example
- Details: woman, 30 years, 60 kg, 165 cm.
- Mifflin-St Jeor: 10 × 60 + 6.25 × 165 − 5 × 30 − 161 = 600 + 1,031.25 − 150 − 161 = 1,320 kcal.
- Revised Harris-Benedict: 447.593 + 9.247 × 60 + 3.098 × 165 − 4.330 × 30 = 1,384 kcal.
- Meaning: even lying in bed all day, her body uses about 1,320 to 1,384 calories.
BMR Examples for Different People
| Profile | Mifflin-St Jeor | Harris-Benedict (revised) |
|---|---|---|
| Woman, 30, 60 kg, 165 cm | 1,320 | 1,384 |
| Man, 30, 75 kg, 175 cm | 1,699 | 1,763 |
| Woman, 50, 70 kg, 160 cm | 1,289 | 1,374 |
| Man, 25, 85 kg, 185 cm | 1,886 | 1,973 |
What Affects Your BMR?
- Body size: heavier and taller people burn more energy at rest.
- Muscle mass: muscle uses more energy than fat, so strength training can raise BMR.
- Age: BMR tends to fall gradually as we get older.
- Sex: men usually have a higher BMR because they tend to carry more muscle.
- Hormones and health: thyroid function and some medical conditions change BMR.
From BMR to Daily Calories
BMR only covers rest. To find how many calories you burn in a real day, multiply your BMR by an activity factor between 1.2 (sedentary) and 1.9 (very active). Our TDEE Calculator does this for you, and the Calorie Calculator turns it into targets for weight loss or gain.
| Activity level | Multiplier | Daily calories for BMR 1,320 |
|---|---|---|
| Sedentary | 1.2 | 1,584 |
| Lightly active | 1.375 | 1,815 |
| Moderately active | 1.55 | 2,046 |
| Very active | 1.725 | 2,277 |
Which BMR Formula Is Most Accurate?
Research comparing the equations has found Mifflin-St Jeor to be the most reliable of the common formulas for most healthy adults, which is why this BMR calculator shows it first. The revised Harris-Benedict formula usually gives a slightly higher number. Neither formula accounts for body fat percentage, so very muscular people may burn more than the BMR calculator suggests.
Who Should Use a BMR Calculator?
Anyone planning a diet can use a BMR calculator to understand their minimum energy needs. Athletes use a BMR calculator to set fuelling targets, and people losing weight use it to make sure their daily intake does not drop too far below what their body needs at rest.
Health note
This BMR calculator provides estimates for healthy adults and is not medical advice. Speak to a doctor or registered dietitian before major changes to your diet.
Frequently Asked Questions
What is a good BMR?
There is no single good BMR. It depends on your size, age, sex and muscle mass. Many adult women fall around 1,200 to 1,500 kcal and many adult men around 1,500 to 1,900 kcal.
How do I calculate my BMR?
Use the Mifflin-St Jeor equation: 10 × weight in kg + 6.25 × height in cm − 5 × age, then add 5 for men or subtract 161 for women. The BMR calculator does this automatically.
Is BMR the same as calories burned per day?
No. BMR is what you burn at rest. Your total daily burn (TDEE) also includes digestion, movement and exercise, so it is higher.
Can I increase my BMR?
Building muscle through strength training is the most reliable way to raise BMR over time. Staying active and eating enough protein also help maintain it.
Should I eat less than my BMR to lose weight?
It is generally not recommended to eat below your BMR for long periods without medical supervision. A moderate deficit below your TDEE is safer and easier to sustain.
Is the BMR calculator free?
Yes. It is free, needs no sign-up and works on phones, tablets and computers.