BMR Calculator
Basal Metabolic Rate — calories your body burns at complete rest. Calculated using the Mifflin-St Jeor equation, the current clinical standard. This free online fitness & health calculator runs entirely in your browser — no signup, no data sent anywhere.
Inputs
Results
How It Works (Formula & Method)
Uses the Mifflin-St Jeor equation: BMR = 10·weight(kg) + 6.25·height(cm) − 5·age + 5 for males, and the same formula −161 for females. This formula was published in 1990 and has been shown to be more accurate than the older Harris-Benedict equation for modern populations.
Worked Example
Scenario: a 30-year-old male, 175 cm tall, weighing 70 kg.
- 10 × 70 (weight) = 700
- 6.25 × 175 (height) = 1,093.75
- 5 × 30 (age) = 150
- BMR = 700 + 1,093.75 − 150 + 5 = 1,648.75 kcal/day
This is the baseline calorie burn at complete rest. To estimate total daily calorie needs, multiply by an activity factor (1.2 sedentary, 1.55 moderately active, 1.9 very active) — that gives you TDEE.
Frequently Asked Questions
What does the BMR Calculator compute?
The BMR Calculator takes 4 input values and returns 1 result. Basal Metabolic Rate — calories your body burns at complete rest. Calculated using the Mifflin-St Jeor equation, the current clinical standard.
Is my data sent to a server?
No. The BMR Calculator runs entirely in your browser using static JavaScript. Your inputs are never transmitted to CalculatorHive or any third party, and nothing is stored after you close the page.
Is this calculator free to use?
Yes. Every calculator on CalculatorHive is completely free. There is no signup, no paywall, and no usage limit. The site is supported by display advertising and affiliate partnerships, which are clearly labeled.
Can I rely on this result for medical decisions?
Results are estimates intended for educational use. Health calculations vary with individual factors that a single formula cannot capture. Always consult a qualified clinician for personal health decisions.
Reviewed against: CDC, NIH, and World Health Organization guidance. Results are estimates for educational use only — not medical advice. Consult a qualified clinician for personal health decisions.