What is BMR and why is it important?

BMR (Basal Metabolic Rate) is the number of calories your body needs to maintain basic physiological functions at rest, such as breathing and circulation. Knowing your BMR helps you estimate daily calorie needs and plan weight goals.

Which formula does this calculator use?

This calculator uses the Mifflin-St Jeor equation, which is widely used and generally more accurate than older formulas for modern populations.

How do I convert BMR to daily calorie targets?

Multiply your BMR by an activity factor (e.g., 1.2 sedentary, 1.55 moderately active) to estimate Total Daily Energy Expenditure (TDEE), which is a practical daily calorie target.

Can I rely on this for medical advice?

No. This tool provides estimates for general use. Consult a healthcare professional for medical or clinical guidance.

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BMR Calculator

Calculate your Basal Metabolic Rate (BMR) - the calories you burn at rest

Units:

Gender

Age

Weight (kg)

Height (cm)

⚠️ Medical Disclaimer: This calculator is for informational and educational purposes only. It is not intended as medical advice, diagnosis, or treatment. Always consult a qualified healthcare professional before making health-related decisions.

About BMR Calculator

This BMR Calculator uses the Mifflin-St Jeor equation to estimate your Basal Metabolic Rate (BMR). BMR is the estimated daily number of calories your body requires to keep basic systems running while at complete rest — breathing, blood circulation, nutrient processing, and cellular repair. Understanding your BMR is the foundation for planning weight loss, maintenance, or muscle gain strategies because it anchors all subsequent calorie calculations.

How This Calculator Works (Step-by-step)

Enter your gender, age, height and weight using the unit toggle — metric or imperial.
The tool applies the Mifflin-St Jeor formula (gender-specific) to compute your BMR.
After BMR is shown, the tool also provides example daily calorie targets using common activity multipliers (sedentary, lightly active, moderately active, very active).
Use the provided targets to guide meal planning, training schedules, or to consult with a nutrition professional for personalized plans.

Example

For example, a 30-year-old woman who is 165 cm tall and weighs 65 kg would have a BMR roughly computed as: (10 × 65) + (6.25 × 165) − (5 × 30) − 161 = approx. 1390 calories/day. Multiplying by a moderate activity factor (1.55) gives a TDEE around 2150 calories/day, which is a practical maintenance estimate.

Use Cases & Benefits

Quickly estimate baseline calorie needs before planning a diet or training program.
Compare different activity scenarios to set realistic daily calorie targets.
Track changes over time — as you gain or lose weight, recalculate BMR to adjust targets.
Use alongside other calculators on this site (TDEE, calorie, macro) for a full nutrition workflow.

Accuracy & Limitations

The Mifflin-St Jeor formula is a widely accepted estimate for most adults, but it remains an estimate. Individual metabolic rates vary due to genetics, hormone levels, body composition, medication, and health conditions. Athletes with high muscle mass can have higher actual energy needs than estimated. Use this calculator as a reliable starting point, and refine targets using real-world tracking (weight and body composition changes) or professional advice.

Privacy & Practical Tips

No personal data is stored by this static calculator — all calculations run in your browser. For the best results, enter accurate, recent measurements and re-run the calculation when your weight or activity level changes. If you are managing a medical condition, consult a qualified healthcare provider before making major dietary changes.

Frequently Asked Questions

What is BMR? +

BMR stands for Basal Metabolic Rate. It is the number of calories your body burns while at rest to maintain basic life functions.

How is BMR different from TDEE? +

BMR is calories burned at rest. TDEE (Total Daily Energy Expenditure) is BMR plus calories burned through physical activity and digestion. TDEE is what you use to determine calorie intake for weight goals.

Does muscle mass affect BMR? +

Yes, muscle tissue burns more calories at rest than fat tissue. People with more muscle mass generally have a higher BMR.

Does BMR change with age? +

Yes, BMR typically decreases as you age due to a loss of muscle mass and changes in hormonal and neurological processes.

How can I increase my BMR? +

The most effective way to increase BMR is to build muscle through strength training. Regular exercise and eating enough protein can also help maintain a healthy metabolism.