BMR Calculator Guide: Mifflin-St Jeor Equation & Resting Calories

Understand basal metabolic rate, use the Mifflin-St Jeor formula, and calculate resting calories with worked examples. Open the free BMR calculator

Quick answer: For a 30-year-old woman (165 cm, 70 kg), Mifflin-St Jeor gives BMR ≈ 1,411 kcal/day at rest. For a 30-year-old man (175 cm, 70 kg), BMR ≈ 1,665 kcal/day. Use the calculator below for your numbers.

Basal metabolic rate (BMR) is the number of calories your body burns at complete rest — before walking, working, or exercise. Our free BMR calculator uses the Mifflin-St Jeor equation, which Google Search data shows is one of the highest-impression query clusters for this page (753 impressions, average position 6.4 in the last 90 days).

What Is BMR and Why Measure It?

BMR represents the energy required for breathing, circulation, cell production, and basic organ function. It is not your total daily calorie target — activity adds on top. Still, BMR is the foundation for nutrition planning, weight management, and fitness coaching.

The Mifflin-St Jeor Equation

Published in 1990, Mifflin-St Jeor is widely used because it performs well across general adult populations. The calculator on GetVendora applies these formulas:

Women

BMR = 10 × weight(kg) + 6.25 × height(cm) − 5 × age − 161

Men

BMR = 10 × weight(kg) + 6.25 × height(cm) − 5 × age + 5

Worked Examples

ProfileInputsApproximate BMR
Woman, 30 years165 cm, 70 kg~1,411 kcal/day
Man, 30 years175 cm, 70 kg~1,665 kcal/day
Woman, 45 years160 cm, 65 kg~1,315 kcal/day

Use the BMR calculator for your exact numbers — results update instantly with no signup.

BMR vs TDEE: What Comes Next?

Total daily energy expenditure (TDEE) = BMR × activity factor. Sedentary office work might use 1.2× BMR; very active jobs or athletes might use 1.6–1.9×. BMR alone answers “resting calories”; TDEE answers “what should I eat today?”

If you are building a restaurant or wellness business on GetVendora, pair this guide with our food cost calculator for menu math — different domain, same precision mindset.

How to Use the BMR Calculator Step by Step

  1. Enter age, sex, height (cm), and weight (kg).
  2. Click calculate — the tool applies Mifflin-St Jeor automatically.
  3. Read the result as resting calories per day.
  4. Multiply by an activity factor if you need TDEE (see FAQ below).

When BMR Estimates May Differ From Reality

Equations are population averages. Muscle mass, thyroid conditions, medications, genetics, and pregnancy can shift real metabolism. Treat BMR as a strong starting estimate — not a medical diagnosis.

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Frequently Asked Questions (FAQ)

What is the Mifflin-St Jeor equation for women?

BMR = 10 × weight(kg) + 6.25 × height(cm) − 5 × age − 161. This is the formula used in the GetVendora BMR calculator for female inputs.

What is the Mifflin-St Jeor equation for men?

BMR = 10 × weight(kg) + 6.25 × height(cm) − 5 × age + 5. Enter your metrics in the calculator for an instant result.

What is the difference between BMR and TDEE?

BMR is calories burned at rest. TDEE includes activity — it is typically BMR multiplied by an activity factor (for example 1.2 for sedentary, 1.55 for moderately active).

Is BMR the same as my daily calorie target?

No. You need additional calories above BMR for daily movement and exercise. Use BMR as the base, then add activity.

How accurate is the Mifflin-St Jeor equation?

It is among the most validated resting-metabolism formulas for general adults. Individual results can still vary by roughly 10%.

Which units does the calculator use?

Metric: kilograms for weight, centimeters for height, and years for age — as labeled on the calculator form.

Calculate Your BMR Now

Get an instant resting calorie estimate with the free Mifflin-St Jeor BMR calculator — no signup required.

Open BMR Calculator