What is BMR and how is it calculated?

BMR (Basal Metabolic Rate) estimates the calories your body uses at rest over 24 hours. We use the Mifflin–St Jeor equation: male = 10·kg + 6.25·cm − 5·age + 5; female = 10·kg + 6.25·cm − 5·age − 161.

How do I switch between US and Metric units?

Use the Units toggle (US or Metric). US entries (ft/in and lb) are automatically converted to metric (cm and kg) behind the scenes so calculations stay accurate.

What is TDEE and which activity factor should I pick?

TDEE is your daily calorie need, computed as BMR × activity factor. Options include: 1.2 (sedentary), 1.375 (exercise 1–3×/week), 1.465 (exercise 4–5×/week), 1.55 (daily or intense 3–4×/week), 1.725 (intense 6–7×/week), and 1.9 (very intense daily or physical job). Choose the one that best matches your routine.

Is BMI or BMR better for planning?

BMI classifies weight relative to height; BMR estimates energy needs. For calorie planning, BMR combined with an activity factor (to get TDEE) is usually more actionable than BMI alone.

What ages are supported?

The calculator supports ages 10–120, consistent with typical BMR formula guidance shown in the interface.

How accurate are the results?

Results are estimates based on population formulas and your inputs. They’re intended for education and convenience and don’t replace medical or nutrition advice.

Metabolic Age (BMR) Calculator

How the Metabolic Age (BMR) Calculator Works

This tool uses the Mifflin–St Jeor equation to estimate your Basal Metabolic Rate (BMR)—the energy your body uses at rest over 24 hours. US entries are converted (lb → kg, ft/in → cm) automatically. The right rail multiplies your BMR by standard activity factors to estimate daily calories for different lifestyles.

How do I calculate my BMR?

Enter age, gender, height, and weight. We apply Mifflin–St Jeor (male: 10·kg + 6.25·cm − 5·age + 5; female: 10·kg + 6.25·cm − 5·age − 161). Results update as you type.

What is a good BMR for a woman?

There isn't one universal “good” BMR. It varies with size, age, and composition. Use BMR as a baseline and pair it with an activity factor to plan calories (TDEE).

Is BMI or BMR better?

BMI classifies weight relative to height. BMR estimates energy needs. For calorie planning, BMR + activity level (TDEE) is more actionable.

How many calories should I eat if my BMR is 1500 to lose weight?

Estimate your maintenance calories (TDEE) using the activity table, then consider a modest deficit (e.g., 300–500 kcal/day) from TDEE. Personalize with professional guidance.

This tool is for education and convenience only and cannot replace professional judgment. For medical decisions, consult a clinician.