BMR calculator.
Understand your resting energy.
Your energy at rest
Resting energy is only part of your daily needs. It is not a daily food target.
Calculated from: 65.0 kg · 168 cm · 30 years
Compare the equations
Add body fat to compare
Add body fat to compare
Different equations use different populations and assumptions. More equations do not make an estimate more accurate.
Use the resting-energy comparison
Mifflin and revised Harris–Benedict use age, height, weight and a sex coefficient. Katch and Cunningham use fat-free mass, which requires body-fat percentage. Cunningham is labelled RMR; it is not identical to BMR measured under strict basal conditions.
For a focused calculation, use the Mifflin calculator or the Katch body-fat calculator. At 80 kg and 20% body fat, fat-free mass is 64 kg: Katch gives about 1,752 and Cunningham gives 1,908 kcal/day. A difference between models does not establish which one is more accurate for you.
Resting energy excludes the activity of a whole day and is not a direct food target. Start maintenance planning in the TDEE calculator, and use the guides below to understand formula selection and measurement uncertainty.
Methods & references
- Our equations, planning rules and scope
- Mifflin et al. (1990), resting energy expenditure
- Roza & Shizgal (1984), revised Harris–Benedict equation
- Cunningham (1980), body composition and basal metabolism
An informational tool; no medical review is claimed. Activity factors and caution thresholds are product planning conventions. Citations do not imply endorsement.
Use the estimate as a starting point.
Track weight and intake under consistent conditions for a few weeks. Adjust the estimate to match your longer-term trend.
Keep your plan connected.
Use the same details across your nutrition tools.
TDEE calculator
Find your daily calorie needs.
Explore toolCalorie deficit
Plan a percentage-based calorie deficit.
Explore toolProtein calculator
Estimate daily protein and per-meal amounts.
Explore toolBMI calculator
Calculate adult BMI and reference ranges.
Explore toolProgress journal
Track body weight and calorie intake.
Explore toolFind your baseline
Enter your details and choose the activity level that looks like an ordinary week.
Choose a direction
Maintain, lose, or gain. Use a manageable change rather than chasing the lowest number.
Check the bigger picture
Track consistent observations over a few weeks. Adjust as your needs change.
How the calculator works
Equations, assumptions and limitations.
Is resting energy my daily calorie target?
No. Resting energy covers only part of your daily energy needs. Use the TDEE calculator to include an activity allowance.
Why do the equations give different answers?
They use different study populations, measurements and assumptions. BMR and RMR also refer to different measurement conditions. Comparing equations does not establish your measured needs.
Do I need a body-fat value?
Mifflin–St Jeor and revised Harris–Benedict do not need it. Katch–McArdle and Cunningham use fat-free mass, so they require a body-fat estimate.
Where is my information stored?
Calculations run in your browser. This tab temporarily keeps your working details when switching tools or languages; closing it clears them. Remember my details saves a persistent profile only if you choose it. Journal entries stay in local browser storage. Sharing puts your chosen inputs into the link, where anyone with it can read them.