BMR Calculator

What is BMR? (What is BMR calculator?)

BMR stands for basal metabolic rate: the number of calories your body burns in a day at complete rest, just to keep you alive. It pays for breathing, circulating blood, keeping your body warm, repairing cells and running your brain, liver and kidneys. For most people BMR makes up 60–70% of all the calories they burn in a day, which makes it the starting point for any weight loss or weight gain plan.

This free BMR calculator estimates your basal metabolic rate from your sex, age, height and weight. It works in kg and cm, kg and feet, or pounds, lets you choose between the three best-known formulas, and shows how many calories you need at each activity level.

How to use this BMR calculator

1. Choose your sex and enter your age.
2. Pick your units and enter your weight and height.
3. Keep the default Mifflin-St Jeor formula, or switch to Harris-Benedict, or to Katch-McArdle if you know your body fat percentage.
4. Read your BMR in kcal per day, then look at the activity table to see your total daily calories.

BMR calculator formula: how to calculate BMR formula

Mifflin-St Jeor equation (recommended)

Men: BMR = 10 × W + 6.25 × H − 5 × A + 5
Women: BMR = 10 × W + 6.25 × H − 5 × A − 161

Harris-Benedict equation (revised by Roza and Shizgal, 1984)

Men: BMR = 88.362 + 13.397 × W + 4.799 × H − 5.677 × A
Women: BMR = 447.593 + 9.247 × W + 3.098 × H − 4.330 × A

Katch-McArdle equation (uses lean body mass)

BMR = 370 + 21.6 × LBM, where LBM = W × (1 − body fat % ÷ 100)

• W = weight in kg
• H = height in cm
• A = age in years
• LBM = lean body mass in kg

How to calculate BMR: worked example

How to calculate BMR for male

A 30-year-old man weighs 70 kg and is 175 cm tall. Mifflin-St Jeor: 10 × 70 + 6.25 × 175 − 5 × 30 + 5 = 700 + 1,093.75 − 150 + 5 = 1,649 kcal/day. The Harris-Benedict formula gives 1,696 kcal/day for the same man. With 15% body fat, Katch-McArdle gives 370 + 21.6 × 59.5 = 1,655 kcal/day.

How to calculate BMR for women

A 30-year-old woman weighs 60 kg and is 162 cm tall. Mifflin-St Jeor: 600 + 1,012.5 − 150 − 161 = 1,302 kcal/day. This is the BMR calculator formula for female users; the only difference from the male equation is the constant (−161 instead of +5).

BMR calculator chart: BMR normal range by age

There is no single "normal" BMR because it depends on body size. The table shows Mifflin-St Jeor results for an average-sized Indian adult (man 65 kg, 168 cm; woman 55 kg, 155 cm) to give a feel for the normal range and how BMR changes by age.

BMR falls by about 50 kcal per decade in this formula, mostly because we lose muscle with age. Strength training slows that drop.

Which BMR calculator is most accurate?

Studies comparing formulas with measured metabolic rates found Mifflin-St Jeor the most accurate for most healthy adults, within 10% of measured BMR for roughly 70–80% of people. That is why the Academy of Nutrition and Dietetics recommends it and why it is the default here. The older Harris-Benedict formula tends to overestimate by a few percent. If you know your body fat percentage from a DEXA scan or a reliable scale, the Katch-McArdle formula can be more accurate for lean, muscular people, because it bases BMR on lean mass rather than total weight. Is a BMR calculator accurate enough to plan a diet? Yes, as a starting point: track your weight for 2–3 weeks and adjust by 100–200 kcal if you are not seeing the change you expect.

BMR vs TDEE: how to calculate BMR and TDEE

BMR is what you burn lying still. TDEE (total daily energy expenditure) adds everything else: walking, work, exercise and digesting food. You get TDEE by multiplying BMR by an activity factor from 1.2 (sedentary) to 1.9 (extra active); the table in the result does this for you. For weight goals, plan your food around TDEE, not BMR. The TDEE calculator explains activity levels in detail.

What is BMR and BMI?

BMI is a ratio of weight to height used to judge whether your weight is healthy; BMR is an energy figure in calories. They answer different questions. Check your weight category with the BMI calculator.

Using your BMR to lose or gain weight

BMR calculator for weight loss and BMR calculator for weight gain

To lose about 0.5 kg a week, eat around 500–550 kcal less than your TDEE each day. Most people should not eat below their BMR for long, because very low intakes cause muscle loss, fatigue and nutrient gaps. The calorie calculator sets a daily target for your goal.

BMR calculator to gain weight

To gain weight, eat 250–500 kcal above your TDEE and combine it with strength training, so more of the gain is muscle. Enough protein matters; see the protein calculator.

What affects basal metabolic rate?

• Muscle mass – muscle burns more energy at rest than fat.
• Body size – taller and heavier people have a higher BMR.
• Age – BMR drops gradually after about 20.
• Sex – men usually have more muscle and a higher BMR.
• Hormones – an under- or overactive thyroid changes BMR significantly.
• Pregnancy and breastfeeding – both raise energy needs; standard BMR formulas do not account for them, so follow your doctor's advice.

This BMR calculator gives estimates for healthy adults and is not medical advice.

BMR calculator for men and women

A BMR calculator for men and a BMR calculator for women use the same inputs; only the constant in the formula changes. The male formula adds 5 and the female formula subtracts 161. Pick your sex above and the tool applies the right one, whether you are a man, or a woman trying to lose weight.

BMR calculator in kg and cm, or kg and feet

As a BMR calculator in kg it takes weight in kilograms and height in cm; choose "kg and feet/inches" to use it as a BMR calculator in kg and feet. This makes it a practical basal metabolic rate calculator India users can fill in without converting units.

BMR calculator with body fat percentage

Choose Katch-McArdle to use this as a BMR calculator with body fat. Because it is based on lean body mass, it is often the best BMR calculator for bodybuilding and athletes with low body fat, and for overweight people it avoids overestimating BMR from fat mass.

BMR calculator with activity level

The result table turns this into a BMR calculator with activity level: it multiplies BMR by 1.2 to 1.9 to show daily calories. This is the practical side of BMR calculator vs TDEE: BMR is the base, TDEE is what you actually burn.

BMR calculator to lose weight

Use the BMR calculator to lose weight by finding your TDEE in the table, then subtracting 500–550 kcal. For a BMR calculator to lose weight female users should keep intake above about 1,200 kcal; men above about 1,500 kcal.

BMR calculator in Hindi (what is BMR in Hindi)

BMR (basal metabolic rate) woh calories hain jo aapka sharir poori tarah aaram karte hue ek din mein kharch karta hai – saans lene, dil dhadakne aur sharir ka taapmaan banaye rakhne ke liye.

BMR calculator online free: what else to know

This BMR calculator online is free and needs no app. A few more notes. Weight in kg and your age both matter, because BMR drops with age. During pregnancy and breastfeeding you need extra calories on top (roughly 340–450 kcal in later pregnancy and about 500 kcal while breastfeeding); and PCOS or thyroid conditions can shift your BMR, so treat the result as a guide. For a BMR calculator bodybuilding use, the Katch-McArdle option with lean mass is usually the better choice.

Best BMR for men and women

There is no best BMR for men or women – a higher BMR simply means your body burns more at rest, usually because you are bigger or more muscular. What matters is matching your food to your total burn.

BMR calculator India: typical values for Indian adults

The same equations work for Indian adults; simply enter weight in kg and height in cm or feet. Because many Indians have less muscle for the same weight, the Katch-McArdle option with a measured body fat percentage can be more accurate. Typical Mifflin-St Jeor results at age 30:

BMR calculator detailed: all ages, lean mass and overweight

This is a detailed BMR calculator with three equations. Mifflin-St Jeor is the default for all ages from 18 upwards; BMR falls by about 5 kcal a year of age in that formula. If you are overweight, Mifflin-St Jeor tends to be the most reliable of the standard equations. If you know your lean mass (for example from a DEXA scan), pick Katch-McArdle, which uses only lean mass: BMR = 370 + 21.6 × lean mass in kg.

BMR calculator scale: smart scales vs equations

Many body composition scales show a BMR value. They estimate it from your weight, height, age and a bioimpedance body fat reading, so the number is still an estimate and can differ from this calculator by 100–200 kcal. Use one method consistently and track the trend.

BMR calculator calories: exercise, protein and breastfeeding

BMR is only the calories you burn at complete rest. Exercise and daily movement are added on top through an activity factor to give TDEE; see the TDEE calculator. Protein does not change BMR much, but digesting it burns more energy than carbs or fat. For breastfeeding, the BMR calculator result stays the same; US dietary guidelines add roughly 330 kcal a day in the first 6 months and about 400 kcal a day afterwards on top of your normal needs.

Calorie calculator zig zag (calorie cycling)

Zig zag (calorie cycling) means eating more on some days and less on others while keeping the weekly average the same. Start from your TDEE, set a weekly target, then move calories between days. Your BMR does not change; only the daily split does.

BMR calculation questions (with answers)

1. A 40-year-old woman weighs 65 kg and is 162 cm tall. What is her BMR by Mifflin-St Jeor? 10 × 65 + 6.25 × 162 − 5 × 40 − 161 = 650 + 1,012.5 − 200 − 161 = 1,301.5 kcal.
2. A 25-year-old man, 80 kg, 180 cm. BMR? 800 + 1,125 − 125 + 5 = 1,805 kcal.
3. His TDEE if moderately active (× 1.55)? 1,805 × 1.55 ≈ 2,798 kcal.
4. Lean mass 60 kg, Katch-McArdle BMR? 370 + 21.6 × 60 = 1,666 kcal.

Frequently asked questions

Last updated 2026-09-18