A free BMR calculator that shows the calories your body burns at rest, by the Mifflin-St Jeor equation, with your TDEE beside it.
See how many calories your body burns at complete rest, and what that means for how much you eat.
You
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Your result
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These calculators give general estimates for healthy adults, not medical advice. Talk to your doctor before you change how you eat or train, especially if you're pregnant, take medication or have a health condition.
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This free BMR calculator shows how many calories your body burns at complete rest: just to breathe, keep your heart beating and stay warm. Enter yourself once, and it shows your BMR and what your day adds on top.
I built it because your BMR is the biggest part of what you burn, often 60% to 70% of it, and it's the number everything else is built on. Knowing it makes every calorie target easier to trust.
Here's how BMR is worked out, and what changes it.
TL;DRKey takeaways
What is a BMR calculator?
A BMR calculator estimates your basal metabolic rate: the energy your body needs at complete rest, with no movement and no food to digest.
This calculator uses the Mifflin-St Jeor equation: 10 × weight in kg + 6.25 × height in cm − 5 × age, plus 5 for men or minus 161 for women.
How to use the BMR calculator
You only need to fill in yourself once, and every health calculator here reads it.
Your numbers stay in this browser.
A worked example
Here's the example the calculator loads when you press Try an example.
A 35-year-old man is 178 cm tall and weighs 78 kg. His BMR is 10 × 78 + 6.25 × 178 − 5 × 35 + 5, which is about 1,723 calories a day.
With exercise 3 to 5 days a week, his TDEE is about 2,670. So his BMR is about 65% of what he burns in a day.
BMR by age, height and weight
Here's the BMR for a few typical people, by the same equation.
- Age
- 25
- Height
- 165 cm
- Weight
- 60 kg
- BMR
- 1,511
- Age
- 35
- Height
- 178 cm
- Weight
- 78 kg
- BMR
- 1,723
- Age
- 45
- Height
- 185 cm
- Weight
- 90 kg
- BMR
- 1,836
- Age
- 25
- Height
- 160 cm
- Weight
- 55 kg
- BMR
- 1,264
- Age
- 35
- Height
- 165 cm
- Weight
- 65 kg
- BMR
- 1,345
- Age
- 45
- Height
- 170 cm
- Weight
- 72 kg
- BMR
- 1,397
Each year of age takes 5 calories off the equation. Weight and height matter far more.
What changes your BMR
You can't change your height or age, but you can change what you're made of.
Muscle
Muscle burns more at rest than fat does. Strength training is the one thing that raises your BMR over time, and the one rep max calculator helps you plan it.
Weight
A bigger body burns more at rest. That's why your BMR falls as you lose weight, and why a target needs updating.
Eating very little
Long stretches of very low calories can slow your metabolism. Stay above your BMR and lose weight slowly instead.
Mistakes to avoid
BMR is easy to misuse as a target.
- Eating at your BMR, which leaves nothing for the rest of your day
- Treating the estimate as exact for your body
- Forgetting to update your weight as it changes
Use your BMR to understand your body, and your TDEE to set a target.
Built on the basics
Your BMR is mostly decided by muscle, and muscle is built by training.
Muscle is the organ of longevity.
For the long view on training, food and sleep together, Outlive by Peter Attia is a good place to start.
Outlive
Outlive by Dr. Peter Attia breaks down the most effective strategies for long-term health and performance, covering exercise, nutrition, sleep, and emotional wellbeing to add years to your life.
I may earn a commission if you make a purchase, at no additional cost to you.
Who is the BMR calculator for?
It's for anyone who wants to understand what their body burns, and these tools take it further.
- TDEE calculator – for what you burn with your activity
- Calorie calculator – for a daily target and a date for your goal
- Macro calculator – for splitting your calories into macros
- Protein calculator – for how much protein keeps your muscle
- Fitness age calculator – for how fit you are for your age
Find your BMR here, then use your TDEE for every plan.
More health calculators
Every health calculator reads the same "You", so you only enter yourself once.
| Calculator | What it answers |
|---|---|
| TDEE calculator | What do I burn in a day? |
| Calorie calculator | How much should I eat? |
| Body fat calculator | How much of me is fat? |
| One rep max calculator | How strong am I? |
Your TDEE is the number to plan meals around.
Plan your health with your AI
Take your numbers further in
BMR Calculator FAQs
Questions about the BMR calculator? Here's what to know.
A BMR calculator estimates the calories your body burns at complete rest.
This free one uses the Mifflin-St Jeor equation and shows your TDEE beside it.
It stands for basal metabolic rate.
With the Mifflin-St Jeor equation: 10 × weight in kg + 6.25 × height in cm − 5 × age, plus 5 for men or minus 161 for women.
It depends on your size, age and sex.
In the examples here it runs from about 1,264 calories for a 25-year-old woman at 55 kg to 1,836 for a 45-year-old man at 90 kg.
No, BMR is only what you burn at rest.
TDEE adds your activity, so it's always higher.
No, eating at your BMR leaves nothing for the rest of your day.
Set your target from your TDEE instead.
Build muscle with strength training, which burns more at rest than fat does.
The equation takes 5 calories off for each year, and muscle tends to fall with age too.
Strength training slows that.
No, it's a general estimate for healthy adults.
Talk to your doctor before you change how you eat or train, especially if you're pregnant, take medication or have a health condition.
Yes, it's free with no login, and your numbers stay in this browser.
I did.
I'm Navid Moazzez, and I made the BMR calculator as one of my free tools on navid.me.
More about me.
Navid Moazzez
AI business strategist & AI OS builder
Navid Moazzez helps creators and founders master AI and build their own AI Operating System (AI OS) to automate their business and life.
Navid.me is reader-supported. When you buy through links on this site, I may earn an affiliate commission. Learn more.
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