Fitness & Health

BMR Calculator for Basal Metabolic Rate

Calculate basal metabolic rate with Mifflin-St Jeor, Harris-Benedict, and Katch-McArdle formulas for calorie planning.

Search intent guide

Use this page when you need a fast answer to bmr calculator

Use this BMR calculator when you want to estimate resting calorie needs before building a full daily intake plan. It is a baseline tool, and it works best when paired with activity-based calorie planning instead of being treated as the final target on its own.

bmr calculatorBMR Calculator2 examples

Editorial review

Reviewed by Smart Calculator Tools Editorial TeamUpdated April 4, 2026

Best for

  • Estimating resting energy needs from common formulas
  • Comparing BMR methods before setting a calorie plan
  • Building a maintenance estimate with TDEE or calorie tools

Before you start

  • Use body data that reflects your current weight and height
  • Remember that BMR is a floor, not your full daily intake
  • Pair the result with actual activity and weekly progress

Inputs

Basal metabolic rate estimate with multiple formulas.

Results

BMR is the estimated calories burned at rest per day.

BMR

1,648.75 kcal/day

Daily calories by activity

ActivityMultiplierCalories/day
sedentary1.2x1,978.5 kcal
light1.38x2,267.03 kcal
moderate1.55x2,555.56 kcal
very1.73x2,844.09 kcal
extra1.9x3,132.63 kcal

Uses your selected formula and body fat input if applicable.

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How this BMR Calculator works

Calculates basal metabolic rate (BMR) using multiple common formulas. This is the calorie burn at rest and a baseline for maintenance planning before applying an activity multiplier.

Best use cases

  • Estimate resting calorie needs before calculating maintenance or cutting and bulking targets.
  • Compare common BMR equations when you want a better baseline for nutrition planning.
  • Build a simple calorie model that starts from body size and age rather than guesswork.

Inputs

  • Biological sex (male or female)
  • Age in years (whole number)
  • Height measured in centimeters or feet/inches
  • Weight measured in kilograms or pounds
  • Formula selection (Mifflin-St Jeor, Harris-Benedict, Katch-McArdle)
  • Body fat percentage for the Katch-McArdle formula

Outputs

  • BMR calories per day
  • Resting energy baseline
  • Starting point for maintenance calculations

Assumptions

  • Adult population averages
  • Measurements are accurate and current

Common mistakes

  • Using BMR as if it were daily maintenance even though normal movement requires an activity multiplier.
  • Entering outdated body weight after a meaningful cut or bulk, which makes the baseline stale.
  • Expecting one formula to be universally correct when body composition can shift which estimate is best.

Tips

  • Pair BMR with activity level for maintenance calories
  • Recalculate after significant weight change
  • Use as a baseline, not a precise prescription

BMR Calculator formula guide

Use these bmr calculator formulas to audit the output or explain it to someone else.

5 formulas

BMR (male) = 10w + 6.25h - 5a + 5
BMR (female) = 10w + 6.25h - 5a - 161
Harris-Benedict (male) = 13.397w + 4.799h - 5.677a + 88.362
Harris-Benedict (female) = 9.247w + 3.098h - 4.330a + 447.593
Katch-McArdle = 370 + 21.6 * leanMass(kg)

BMR Calculator examples

Review a ready-made bmr calculator scenario, copy it, then tweak inputs to match your case.

Example

2 inputs2 outputs

Male example

Inputs

  • Male, 30 years, 180 cm
  • Weight 80 kg

Outputs

  • BMR about 1,780 calories
  • Use activity multiplier for maintenance

BMR is the resting baseline before daily activity.

Example

2 inputs2 outputs

Female example

Inputs

  • Female, 30 years, 165 cm
  • Weight 60 kg

Outputs

  • BMR about 1,330 calories
  • Use activity multiplier for maintenance

Results are estimates and vary by body composition.

BMR by weight (male, 30y, 175cm)

4 of 4 rows
WeightBMR estimate
60 kg1,520
70 kg1,620
80 kg1,720
90 kg1,820

Each 10 kg adds about 100 calories in this profile.

BMR vs weight

Highest: 90 (1,820)Lowest: 60 (1,520)
WeightCalories per day

Focus point

60

1,520

Position

#1 of 4

Original order

Share of total

22.75%

Total: 6,680

PositiveNegative

Profile assumes male, 30 years, 175 cm height.

For informational use only and not medical advice.

References

  • Mifflin-St Jeor equation
  • Clinical nutrition energy estimation basics

FAQ

BMR Calculator FAQ

What does the BMR Calculator do?

Calculates basal metabolic rate (BMR) using multiple common formulas. This is the calorie burn at rest and a baseline for maintenance planning before applying an activity multiplier. It is part of our fitness & health toolkit.

When should I use this calculator?

Use it when you need to Estimate resting calorie needs before calculating maintenance or cutting and bulking targets. Compare common BMR equations when you want a better baseline for nutrition planning.

What inputs do I need?

Typical inputs include Biological sex (male or female), Age in years (whole number), Height measured in centimeters or feet/inches.

How are the results calculated?

We follow the formulas and assumptions outlined in the "How this calculator works" section. You will see outputs like BMR calories per day, Resting energy baseline, Starting point for maintenance calculations.

What mistakes should I avoid?

Common mistakes include Using BMR as if it were daily maintenance even though normal movement requires an activity multiplier. Entering outdated body weight after a meaningful cut or bulk, which makes the baseline stale.

Can I share or download the results?

Use the Copy link or Print buttons to share your results. If a table or chart appears, you can download the data as CSV.

Is my data stored?

No. Calculations run in your browser and we do not store your inputs.

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