BMR Calculator
Free BMR calculator using Mifflin-St Jeor. Get your basal metabolic rate, TDEE, and daily calorie target for weight loss, maintenance, or muscle gain.
What is BMR and why does it matter?
Basal Metabolic Rate is the number of calories your body burns in a 24-hour period while completely at rest - no movement, no digestion, no activity. It represents the minimum energy needed to sustain vital functions: breathing, circulation, cell repair, and hormone production. BMR accounts for roughly 60 to 70 percent of total daily calorie burn for sedentary individuals. This calculator uses the Mifflin-St Jeor equation, validated as the most accurate BMR formula for the general population by the Academy of Nutrition and Dietetics. Your BMR is the foundation of all calorie targeting for weight loss, maintenance, or muscle building.
BMR by gender, age, and weight - 2025 US benchmarks
The average BMR for American women is approximately 1,400 kcal per day; for men, approximately 1,800 kcal per day, according to NHANES data. BMR peaks in early adulthood and declines by 1 to 2 percent per decade after age 30 due to muscle loss. Body weight is the single largest driver: a 220 lb person has a BMR roughly 30 percent higher than a 155 lb person of the same height and age. The CDC recommends adults achieve at least 150 minutes of moderate activity weekly, which translates to an activity factor of 1.375 in TDEE calculations - adding roughly 300 to 500 kcal above BMR.
How to use your BMR to hit your weight goal
Start by calculating your TDEE (BMR x activity factor). For weight loss, create a 300 to 500 calorie daily deficit from TDEE - large enough to produce results without triggering metabolic adaptation. For muscle gain, add 200 to 300 calories above TDEE and prioritize protein at 0.8 to 1 gram per pound of body weight. Recalculate every 10 to 15 pounds of weight change, as your BMR shifts with body composition. Use MyPlate.gov for free USDA-backed meal planning tools. If weight loss stalls after 3 consistent weeks, reduce calories by 100 and reassess activity level before making larger changes.
Frequently asked questions
What is a good BMR for a woman?
The average BMR for an American woman is approximately 1,350 to 1,500 kcal per day, depending on height, weight, and age. A BMR above 1,500 is considered above average for women. BMR is not what you should eat - your TDEE, which is BMR multiplied by your activity factor, is the number that guides your actual daily calorie intake.
What is a good BMR for a man?
The average BMR for an American man ranges from 1,700 to 1,900 kcal per day. Taller, heavier, or younger men will have higher BMRs. BMR represents resting calorie burn only - a moderately active man with a BMR of 1,800 will have a TDEE of roughly 2,790 kcal, which is the actual calorie target for maintaining weight.
What is the difference between BMR and TDEE?
BMR (Basal Metabolic Rate) is the calories your body burns at complete rest - breathing, heart function, and cell maintenance only. TDEE (Total Daily Energy Expenditure) is BMR multiplied by your activity factor, representing the total calories burned in a real day including movement, exercise, and digestion. TDEE is the number you use to set a calorie goal.
How many calories should I eat to lose weight?
To lose 1 pound per week, subtract 500 from your TDEE. For a 155 lb moderately active woman with a TDEE of 2,100, that means eating 1,600 calories per day. A deficit larger than 750 calories per day risks muscle loss and metabolic adaptation. The safest rate of fat loss is 0.5 to 1 pound per week for most adults.
Does BMR change with age?
Yes. BMR declines by approximately 1 to 2 percent per decade after age 30, primarily due to the natural loss of lean muscle mass. This is why a 50-year-old burns fewer calories at rest than a 30-year-old of the same weight. Resistance training is the most effective way to preserve BMR with age by maintaining muscle tissue.
User Comments
Help Us Improve
Found a bug or want a feature? Let us know!