BMR Calculator
Want your resting calorie number? Enter age, height, weight, and sex and you will get your BMR. It is the baseline for any calorie plan.
TL;DR
- BMR depends on sex, age, weight, and height
- Mifflin-St Jeor Equations: Men: BMR = (10 × W) + (6.25 × H) - (5 × A) + 5 | Women: BMR = (10 × W) + (6.25
- Example 1: BMR calculation for a 30-year-old woman
How it works
BMR depends on sex, age, weight, and height. People with more muscle burn more at rest.
The math
Apply the Mifflin-St Jeor equation with weight, height, age, and a sex adjustment.
W represents weight in kg, H is height in cm, A is age in years. The final adjustment factors differ between biological sexes.
Examples
Example 1: BMR calculation for a 30-year-old woman
- Weight (W): 60 kg, Height (H): 165 cm, Age (A): 30
- Apply math: (10 × 60) + (6.25 × 165) - (5 × 30) - 161
- Step calculations: 600 + 1031.25 - 150 - 161 = 1320.25
- Result: Base metabolic rate is 1,320 calories per day.
When to use it
✦ Resting Energy Expenditure Baselines
Understand the bare minimum calories your body requires to function during periods of injury or complete bed rest.
✦ Personalized Calorie Goal Architectures
Build nutritional programs using your BMR as the baseline before adding active exercise calories.
✦ Analyzing Metabolic Adaptations
Monitor how BMR drops during weight loss, allowing you to avoid dieting plateaus.
⚠ Common mistakes
- Eating Below Your BMR: Restricting calorie intake below your BMR can cause muscle loss, fatigue, and nutritional deficiencies.
- Ignoring Muscle Mass: Assuming two individuals with identical weights have the same BMR, regardless of lean tissue differences.
FAQ (6)
Does BMR decrease with age?
Yes, BMR decreases as muscle mass naturally declines and metabolic efficiency slows down.
How can I increase my BMR?
The most effective way is to build muscle tissue through strength and resistance training.
What happens to my weight, height or other health data?
It never leaves your phone. BMI, BMR, body-fat — all computed on-device, no upload, no account. That's intentional for health data: you can check a BMI of 22.8 or a TDEE of 2,100 kcal without worrying about a server log. Closing the tab clears the form from memory.
Does it work offline at the gym or on a plane?
Yep. Once the page has loaded, the calculators are fully offline-first. I've used the pace and BMI tools in airplane mode between flights — no spinner, no retry, just instant numbers. Same for sleep cycles if you're planning a shift.
Can my doctor rely on these numbers?
They're solid estimates using published formulas (WHO for BMI, Mifflin-St Jeor for BMR, CKD-EPI for GFR) but they're not a diagnosis. Think of them as a conversation starter: good for tracking trends, but your GP or nephrologist should interpret GFR, heart age or pregnancy dates with labs and context. We link the sources at the bottom for that reason.
How can I share my result with a trainer or doctor?
Use 'Share Link' in the results panel. It builds a URL with your inputs — for example BMI 70kg/175cm — so they see exactly what you entered. No data is stored on our side, the link just carries the numbers.
Sources & References
⚠ Health Disclaimer
This tool provides estimates for informational purposes only and does not constitute medical, veterinary, or professional advice. Always consult a qualified healthcare professional before making decisions about your health or treatment.