BMR Calculator

100% free · Runs 100% in your browser · No signup needed

Medical disclaimer: This calculator is for informational purposes only and is not medical advice. Always consult a qualified healthcare professional for medical decisions.

Gender

Male Female

Age (years)

Height (cm)

Weight (kg)

Your BMR (Mifflin-St Jeor)

Fill in the fields above and your BMR appears here.

Daily calorie needs (TDEE) by activity level

Your activity-level estimates will appear here.

About BMR Calculator

What is the BMR Calculator?

The BMR Calculator is a free online health tool that estimates your Basal Metabolic Rate, the number of calories your body burns at complete rest just to keep you alive. Breathing, circulating blood, maintaining body temperature and powering your brain all consume energy around the clock, and for most people this baseline accounts for 60 to 70 percent of all calories burned each day. Knowing your BMR is the starting point for any serious weight loss, weight gain or maintenance plan.

This calculator uses the Mifflin-St Jeor equation, regarded by nutrition researchers as the most accurate BMR formula for the general population. For men it is 10 times weight in kilograms, plus 6.25 times height in centimeters, minus 5 times age in years, plus 5. For women the same formula ends with minus 161. Enter your details and get your daily baseline in seconds.

How to Use the BMR Calculator

Select your sex: Choose male or female, since the Mifflin-St Jeor equation uses different constants for each.
Enter your age: Type your age in years. Metabolism naturally slows with age, so accuracy here matters.
Enter your height: Add your height in centimeters or feet and inches, whichever you prefer.
Enter your weight: Add your current weight in kilograms or pounds for the most up-to-date result.
Read your BMR: Your basal metabolic rate appears instantly, with an estimate of total daily needs at common activity levels.

Key Benefits

Mifflin-St Jeor accuracy: Uses the research-backed gold standard equation, not outdated formulas.
Activity multipliers: See estimates from sedentary to very active lifestyles.
Weight goal planning: Understand the calorie baseline behind any diet plan.
Metric and imperial: Works with kilograms or pounds, centimeters or feet and inches.
Free with no signup: Recalculate as often as your weight changes, with complete privacy.

Pro Tips

BMR is not your total burn: Add activity on top. A sedentary office worker burns roughly 1.2 times BMR, while a very active person burns about 1.9 times.
Recalculate after weight changes: Every 5 kg of weight change shifts your BMR noticeably, so update your numbers monthly.
Do not eat below BMR long-term: Consistently eating less than your basal needs can slow metabolism and cost muscle.
Muscle raises BMR: Strength training builds metabolically active tissue, which is the healthiest way to lift your baseline burn.

Frequently Asked Questions

What is the difference between BMR and TDEE?

BMR is what you burn at total rest. TDEE, total daily energy expenditure, adds all activity, exercise and digestion on top of BMR.

How accurate is the Mifflin-St Jeor equation?

It is accurate within about 10 percent for most adults, which is better than older formulas. Athletes with very high muscle mass may burn more than it predicts.

Does BMR change with age?

Yes, it typically declines 1 to 2 percent per decade after age 20, mostly because of gradual muscle loss.

Can I increase my BMR?

Building muscle through resistance training is the most effective way. Crash dieting does the opposite and can lower it.

Related Tools

Plan meals with the Calorie Calculator, check your weight category using the BMI Calculator, and work with portions via the Percentage Calculator.

Medical Disclaimer: This calculator is for informational and educational purposes only and is not medical advice. Calorie needs vary with health conditions, medications and individual metabolism. Always consult a qualified healthcare professional or registered dietitian before starting a diet or exercise program.

When it comes to your health, small numbers drive big decisions. If you run a fitness blog or nutrition site, FistHost web hosting keeps it loading fast with plans from $0.99/mo and a free domain included.

User Reviews

No reviews yet. Be the first to review this tool!