What is the difference between BMR and TDEE?

BMR is calories burned at complete rest with zero activity. TDEE (Total Daily Energy Expenditure) multiplies BMR by an activity factor to include exercise, work, and digestion.

Which BMR formula is considered the most accurate?

The Mifflin-St Jeor equation is clinically recognized by the Academy of Nutrition and Dietetics as the most reliable BMR formula for the general population. The Katch-McArdle formula is preferred if body fat percentage is known.

Can eating below your BMR be dangerous?

Yes. Consistently eating below your BMR can cause nutrient deficiencies, muscle loss, metabolic adaptation (slowing metabolism), fatigue, and hormonal disruptions.

How can I increase my Basal Metabolic Rate?

Building lean muscle through resistance training is the most effective way to increase BMR, as muscle tissue burns significantly more calories at rest than fat tissue.

How does age affect BMR?

BMR typically declines by about 1%–2% per decade after age 30, primarily due to natural loss of muscle mass (sarcopenia) unless counteracted by strength training.

Health & Fitness Cluster

BMR Calculator (Basal Metabolic Rate & Resting Calories)

Calculate the exact number of daily calories your body burns at rest to maintain vital life functions.

TL;DR: BMR Calculator calculates your Basal Metabolic Rate using the clinical Mifflin-St Jeor equation, determining base energy expenditure before physical activity.

Units

Gender

Age (years)

Weight (kg)

Height (cm)

Activity level

What Is Basal Metabolic Rate (BMR) and What Is the Mifflin-St Jeor Formula?

Basal Metabolic Rate (BMR) is the minimum amount of energy (in calories) your body requires to maintain essential physiological functions (breathing, circulation, organ function) at complete rest. Under the Mifflin-St Jeor equation: Men: BMR = (10 × weight in kg) + (6.25 × height in cm) - (5 × age in years) + 5; Women: BMR = (10 × weight in kg) + (6.25 × height in cm) - (5 × age in years) - 161.

How to Use the BMR Calculator

Our BMR Calculator performs high-precision mathematical operations directly in your browser with zero latency and complete client-side privacy.

Select Gender (Male or Female) and enter your current Age in years.
Enter your Height (in cm or feet/inches) and Weight (in kg or lbs).
Optionally enter your body fat percentage to enable the Katch-McArdle formula.
Click 'Calculate BMR' to view your resting daily caloric baseline.
Use your BMR to calculate Total Daily Energy Expenditure (TDEE) and nutrition plans.

Mathematical Formula & Equations

Where W is weight in kg, H is height in cm, A is age in years, and S is gender constant (+5 for males, -161 for females).

\[ \text{Mifflin-St Jeor: } \text{BMR} = 10W + 6.25H - 5A + S \]

Calculation Example

A 30-year-old male weighing 80 kg at 180 cm: $$\text{BMR} = (10 \times 80) + (6.25 \times 180) - (5 \times 30) + 5 = 800 + 1125 - 150 + 5 = 1,780 \text{ kcal/day}$$

100% Client-Side Privacy & Data Security

All calculations, amortization schedules, variables, and sensitive numerical datasets execute 100% locally in your web browser memory. Your financial, medical, and personal values are never transmitted, logged, or uploaded to any external server.

Frequently Asked Questions

: BMR is calories burned at complete rest with zero activity. TDEE (Total Daily Energy Expenditure) multiplies BMR by an activity factor to include exercise, work, and digestion.
: The Mifflin-St Jeor equation is clinically recognized by the Academy of Nutrition and Dietetics as the most reliable BMR formula for the general population. The Katch-McArdle formula is preferred if body fat percentage is known.
: Yes. Consistently eating below your BMR can cause nutrient deficiencies, muscle loss, metabolic adaptation (slowing metabolism), fatigue, and hormonal disruptions.
: Building lean muscle through resistance training is the most effective way to increase BMR, as muscle tissue burns significantly more calories at rest than fat tissue.
: BMR typically declines by about 1%–2% per decade after age 30, primarily due to natural loss of muscle mass (sarcopenia) unless counteracted by strength training.

Cite This Calculator

Need to reference this online calculator in a financial proposal, academic paper, blog post, or classroom curriculum? Copy a citation below.

NexLove.org. (2026). BMR Calculator [Online Calculation Tool]. https://nexlove.org/tools/bmr-calculator

“BMR Calculator.” NexLove.org, 2026, nexlove.org/tools/bmr-calculator.

NexLove.org (2026) BMR Calculator. Available at: https://nexlove.org/tools/bmr-calculator (Accessed: 2026).

@misc{nexlove_bmr_calculator,
  title = {BMR Calculator},
  author = {{NexLove.org}},
  year = {2026},
  url = {https://nexlove.org/tools/bmr-calculator}
}

Embed This Tool

Add the live BMR Calculator to your own website with this snippet — it loads the real, working calculator in an iframe.

<iframe src="https://nexlove.org/embed/bmr-calculator.html" width="100%" height="600" style="border:1px solid #e2e8f0;border-radius:12px" title="BMR Calculator — NexLove.org" loading="lazy"></iframe>

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