Body & Fitness

BMR Calculator

Estimate basal metabolic rate in kcal per day with the Mifflin-St Jeor formula, TDEE context, examples, and nutrition planning limits.

By Calculator Suite Pro Editorial Team | Last updated March 18, 2026

Use this estimate as body-metric context, then compare nearby fitness tools when one number needs more perspective.

Explore the Body & Fitness group for nearby calculators, examples, and guide links.

SexWeight (kg)Height (cm)Age (years)

BMR

1699 kcal/day

Formula

Mifflin-St Jeor

Use

Resting calories

Use TDEE for daily needs.

Resting calories in context

Turn BMR into a safer nutrition starting point

BMR estimates resting energy use. It is useful as a baseline, but most nutrition planning should start from total daily energy needs instead.

Maintenance planning

Use BMR first, then open TDEE to include activity before setting calorie targets.

Calorie target review

If a diet target falls below BMR, pause and review whether the plan is too aggressive or needs professional guidance.

Body-weight changes

Recalculate after meaningful weight changes because the estimate changes with body size.

What this body estimate does not measure

BMR formulas are estimates and do not measure metabolism directly.
They do not account well for pregnancy, clinical nutrition needs, eating-disorder recovery, or some medical conditions.
Activity, lean mass, medication, sleep, and illness can change real energy needs.

When to get a professional check

Use TDEE and real weight trends over two to three weeks to adjust estimates.
For clinical nutrition, pregnancy, or medical conditions, use a qualified dietitian or clinician.

TDEE Calculator Macronutrient Calculator BMI Calculator

About this calculator

BMR (Basal Metabolic Rate) estimates how many calories your body burns per day at rest. Think of it as the energy needed for basic functions like breathing, circulation, and temperature regulation.

This calculator uses the Mifflin-St Jeor formula, a commonly used modern equation for estimating BMR in adults.

BMR is only one part of daily energy needs. For a fuller estimate that includes activity, use the TDEE calculator.

How the estimate is calculated

A short explanation of how the body or training inputs are turned into an estimate.

Mifflin-St Jeor estimates BMR using weight, height, age, and sex.
Men: BMR = 10w + 6.25h - 5a + 5.
Women: BMR = 10w + 6.25h - 5a - 161.
The result is kcal/day, representing energy burned at rest over 24 hours.

Formula and interpretation limits

These are the formulas, assumptions, and screening limits used by this body or fitness calculator.

Mifflin-St Jeor estimates BMR using weight, height, age, and sex.
Men: BMR = 10w + 6.25h - 5a + 5.
Women: BMR = 10w + 6.25h - 5a - 161.
The result is kcal/day, representing energy burned at rest over 24 hours.

Where this estimate can help

Use these scenarios to decide whether the output is useful for tracking, planning, or a basic screen.

Estimating resting calorie burn
Setting a starting point for nutrition planning
Comparing calorie needs between individuals
Building a calorie deficit/surplus plan (with TDEE)
Understanding how weight/height/age affect energy needs
Fitness coaching and baseline planning
Education (learning BMR formulas)
Tracking estimated BMR changes over time

How to enter body metrics

Select sex.
Enter weight (kg), height (cm), and age (years).
Calculate to see BMR in kcal/day.
Use the result as an estimate, not an exact lab measurement.
Open TDEE calculator to include activity level.

Body-metric mistakes to avoid

Confusing results usually come from measurement errors, formula assumptions, or over-interpreting a single number.

Confusing BMR with TDEE (BMR does not include activity).
Entering height in meters instead of centimeters.
Using BMR as a guaranteed calorie target (it is an estimate).
Ignoring that body composition can affect real metabolism.
Using the formula for children/teens without proper guidance.

Interpretation tips

Use BMR as a baseline, then use TDEE for daily maintenance calories.
If your goal is weight change, adjust from TDEE, not from BMR.
Track trends: if your weight changes, your BMR estimate will change too.
Pair with Macro Calculator to convert calories into macro targets.
For medical conditions, consult a qualified professional before changing diet.

Glossary

Quick definitions for body and fitness terms used on this page.

BMR

Basal Metabolic Rate: estimated calories burned per day at rest.

kcal/day

Kilocalories per day, a unit of daily energy use.

Body-metric examples

Typical adult example

Input: Sex: Men, Weight: 75kg, Height: 175cm, Age: 30

Output: BMR estimate shown in kcal/day

Another example

Input: Sex: Women, Weight: 60kg, Height: 165cm, Age: 28

Output: BMR estimate shown in kcal/day

Weight change impact

Input: Increase weight by 5kg

Output: BMR estimate increases

Body and fitness guides

Related explainers that add context around formulas, trends, and interpretation limits.

Browse all articles

FAQ

What is the difference between BMR and TDEE?

BMR is calories burned at rest. TDEE includes activity and represents daily maintenance calories.

Is Mifflin-St Jeor accurate?

It is a widely used estimate for adults, but individuals vary. Lab tests can differ from formula estimates.

Does muscle mass affect BMR?

Yes. More lean mass often increases energy needs, which is why BMR is an estimate.

Can I use BMR to lose weight?

Use TDEE for daily targets, then create a reasonable deficit or surplus based on goals.

Why is sex required?

The formula uses a sex-specific constant for typical body composition differences.

Is BMR the same as resting metabolic rate (RMR)?

They are related. RMR is similar but measured under less strict conditions. In practice, people use them interchangeably.

Body-metric references and update notes

Last updated: March 18, 2026

Reviewed by Calculator Suite Pro Editorial Team.

Use the output for general context; clinical or high-stakes decisions need professional confirmation.

Related body and fitness calculators

Use nearby body-metric tools together when one estimate needs more context.