BMR Calculator for Women: Basal Metabolic Rate After 40

Your basal metabolic rate (BMR) is the number of calories your body burns at complete rest, just to keep your heart beating, your lungs breathing and your body warm. For most women it makes up more than half of the calories they burn each day.

This free BMR calculator for women uses three trusted formulas and also shows how many calories you burn in a full day at different activity levels. No sign-up, and nothing you enter is saved.

If you know your body fat %, the lean body mass calculator also estimates BMR from lean mass.

BMR Calculator for Women

Find your basal metabolic rate: the calories your body burns at rest, just to keep you alive.

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If you know it, we’ll also show the Katch-McArdle result. Don’t know it? Try our body fat calculator.
Please enter a realistic age, height and weight (and body fat between 5 and 70%, or leave it blank).

Main result uses the Mifflin-St Jeor equation for women, which studies have found to be the most accurate everyday formula. Real BMR can differ by about 10% from any estimate.

What Is BMR?

BMR is the energy your body needs at rest for basic functions: breathing, circulation, making cells, and keeping your temperature steady. It doesn’t include walking, exercise, or even digesting food.

Your total daily calories (often called TDEE) are your BMR plus everything else you do. That’s why the calculator multiplies your BMR by an activity level.

Average BMR for Women by Weight

For a 45-year-old woman who is 5’4″ (Mifflin-St Jeor). Use the BMR calculator for women above for your exact number:

WeightBMR (calories/day)
130 lbabout 1,220
150 lbabout 1,310
170 lbabout 1,400
190 lbabout 1,490

How BMR Changes With Age

For a woman who is 5’4″ and 165 lb:

AgeBMR (calories/day)
40about 1,400
50about 1,350
60about 1,300
70about 1,250

The formulas lower BMR by about 5 calories a year. In real life, the bigger drop usually comes from losing muscle, which is why strength training matters so much after 40.

The 3 Formulas Our BMR Calculator for Women Uses

FormulaFor womenBest for
Mifflin-St Jeor (main)10 × weight (kg) + 6.25 × height (cm) − 5 × age − 161Most adults; found to be the most accurate everyday formula in a systematic review
Harris-Benedict (revised 1984)447.593 + 9.247 × weight (kg) + 3.098 × height (cm) − 4.330 × ageThe classic formula; often a little higher
Katch-McArdle370 + 21.6 × lean body mass (kg)If you know your body fat %; often better for very muscular people

BMR vs. How Much You Should Eat

BMR is not a target to eat. Eating at or below your BMR for long periods can make it harder to get enough nutrients and can lead to muscle loss. Wondering if 1,200 calories is enough? See is 1,200 calories too low for a woman over 50.

  • To maintain your weight, eat about your total daily calories (BMR × activity level).
  • To lose weight, a gap of about 250 to 500 calories a day below that is a common, steady approach.

Get a personal target with our calorie calculator for women, then split it into protein, carbs and fat with the macro calculator.

How to Support Your Metabolism After 40

  • Lift weights or do resistance exercise 2 or more days a week. Muscle burns more calories than fat, even at rest.
  • Eat enough protein, spread across meals. Find your number with the protein calculator.
  • Keep moving during the day. Everyday movement (walking, chores, standing) adds up. See how far you walk with the steps to miles calculator.
  • Sleep well. Short sleep is linked with more hunger and weight gain.

Frequently Asked Questions

What is a normal BMR for a woman?
Most adult women have a BMR between about 1,200 and 1,500 calories a day, depending on size, age and muscle.

Does menopause lower your BMR?
Research suggests energy use can drop a little during the menopause transition, and fat tends to shift toward the belly. Muscle loss with age plays a big part, so strength training helps.

Is BMR the same as RMR?
Almost. Resting metabolic rate (RMR) is measured under slightly less strict conditions and is usually a little higher. Calculators often use the terms interchangeably.

Which BMR formula is most accurate?
For most women, Mifflin-St Jeor, which is the main result in our BMR calculator for women. Real BMR can still differ by about 10% from any formula. A lab test (indirect calorimetry) is the only way to measure it exactly.

Related Tools

This calculator is for general information only and is not medical advice. Read our Medical Disclaimer and Editorial Policy.

Sources

Health note: Content on this site is for general information only and is not medical advice. Always consult your doctor about health concerns.

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