Enter age, gender, height, weight, and activity level to estimate your basal metabolic rate, maintenance calories, and a practical calorie target for fat loss, recomposition, or lean mass gain.
You only need five inputs to get a solid estimate of your basal metabolic rate, your maintenance calories, and a realistic starting point for a calorie deficit or calorie surplus.
Type in your age, gender, height, and weight using metric or imperial units. These values drive the Mifflin-St Jeor equation.
Pick the option that matches your average week, not your hardest day. The activity multiplier turns BMR into an estimate of total daily energy expenditure.
Compare your BMR, TDEE, and suggested calorie goals with your real progress over the next two to three weeks and adjust only if your results say you should.
Your basal metabolic rate is your resting engine. Your TDEE is the number you use to plan meals because it includes movement, workouts, and digestion. Once you know both numbers, you can set a practical calorie deficit for fat loss, stay near maintenance calories for weight stability, or use a small calorie surplus for lean mass gain.
That is why the best-ranking competitor pages spend time explaining how to act on the result. A calculator is most useful when it helps you make better decisions after the number appears on the screen.
Basal metabolic rate is the number of calories your body would burn at complete rest. It covers basic functions such as breathing, circulation, body temperature control, cell repair, and organ function. In most adults, basal metabolic rate is the largest share of total daily energy expenditure, which is why it serves as the foundation of calorie planning.
TDEE stands for total daily energy expenditure. It includes your resting metabolic rate, daily walking, chores, workouts, and the calories used to digest food. If you want your maintenance calories, TDEE is the better number. If you want to lose weight, subtract from TDEE instead of guessing from BMR alone.
The weight-loss goal uses a 500-calorie reduction from estimated maintenance. That is a common starting point for steady progress without extreme dieting. The maintenance goal reflects your current daily energy needs. The weight-gain goal adds 500 calories per day, though many lifters prefer a smaller calorie surplus to support muscle growth with less fat gain.
Suppose you are a 35-year-old woman who is 165 cm tall, weighs 70 kg, and exercises lightly three days per week. Her Mifflin-St Jeor BMR is:
10 x 70 + 6.25 x 165 - 5 x 35 - 161 = 1,395 calories/day
Multiply 1,395 by the lightly active factor of 1.375 and you get a TDEE of about 1,918 calories per day. A practical calorie deficit could start near 1,400 to 1,500 calories per day, while maintenance stays near 1,900 and a slow lean gain phase could start near 2,100.
You would then compare that estimate with scale trends, gym performance, energy, and hunger. If your body weight does not move as expected after two to three consistent weeks, adjust the target by about 100 to 200 calories per day.
If you want to know how to calculate BMR manually, this section walks you through the equation, the units, and the activity multiplier that turns resting calorie burn into a full daily calorie target.
This calculator uses the Mifflin-St Jeor equation because it is one of the most widely used formulas for estimating basal metabolic rate in healthy adults. It needs only four inputs: body weight in kilograms, height in centimeters, age in years, and sex.
Men: BMR = 10W + 6.25H - 5A + 5
Women: BMR = 10W + 6.25H - 5A - 161
In these formulas, W is weight in kilograms, H is height in centimeters, and A is age in years. The sex-specific constant adjusts for typical differences in body composition seen in the original data.
Imagine you are a 28-year-old man who is 180 cm tall and weighs 82 kg.
That means maintenance calories are about 2,800. A moderate calorie deficit could start near 2,300, while a slow muscle-gain phase could start near 3,000 if recovery and training are strong.
Some calculators also mention Harris-Benedict or Katch-McArdle. The Harris-Benedict equation is older and still common online. The Katch-McArdle formula uses lean body mass, so it can be helpful when you know your body-fat percentage. Even so, all of these methods are still estimates. Your real maintenance calories depend on how your body responds over time.
This is why a calorie deficit calculator built from BMR should be treated as a starting point. Track weekly body-weight averages, hunger, recovery, and gym performance. Real-world feedback always beats a formula once you have the first estimate.
If you work at a desk and average 4,000 steps per day, choose sedentary unless you also train hard several days per week. For example, a 42-year-old man who is 175 cm and 95 kg has a BMR near 1,824 calories. At a sedentary multiplier of 1.2, maintenance is about 2,189. A practical weight-loss intake could start near 1,700 to 1,800 calories.
If you lift four days per week and walk a lot, moderate activity often fits better than lightly active. A 30-year-old woman at 160 cm and 60 kg has a BMR near 1,289 calories. At 1.55 activity, maintenance is about 1,998. Eating close to 2,000 calories helps support training while keeping body weight stable.
You do not always need a 500-calorie surplus to build muscle. A 24-year-old man at 185 cm and 78 kg has a BMR near 1,825 calories. If he is very active, TDEE is about 3,146. Instead of jumping straight to 3,646, he may choose 3,250 to 3,350 calories to support growth while limiting excess fat gain.
If you are new to lifting and have body fat to lose, eating near maintenance calories with high protein can work well. For example, a 27-year-old woman at 170 cm and 82 kg has a BMR near 1,573 calories. At light activity, TDEE is about 2,163. She could start around 1,900 to 2,000 calories while focusing on resistance training, sleep, and protein.
With age, resting metabolic rate can drift down if lean body mass falls. A 62-year-old man at 172 cm and 76 kg has a BMR near 1,544 calories. If he is lightly active, maintenance is around 2,123. Rather than chasing aggressive weight loss, he may do better with a small calorie deficit, enough protein, and resistance work to reduce muscle loss.
If fat loss slows after a long cut, your first step is to verify real intake and activity, not to assume the calculator is wrong. Lower body weight reduces calorie needs, and metabolic adaptation can make the gap smaller than it was at the start. Recalculate with your current stats, compare with weekly averages, and then adjust by 100 to 200 calories if needed.
One of the biggest gaps on the original page was a clear explanation of how to turn basal metabolic rate into a useful daily calorie target. This section closes that gap with the activity multipliers you need for real planning.
The most common mistake is choosing an activity level based on a few hard workouts instead of total weekly movement. If you train for one hour but sit the rest of the day, your true maintenance calories may still be closer to lightly active than very active. A step counter and honest food logging usually improve accuracy more than switching formulas.
If your progress does not match the calculator, keep calories steady for two weeks, track scale averages, and then adjust in small steps. That process is more useful than changing calculators every few days.
Online calorie tools are built for convenience, not lab precision. Indirect calorimetry can measure resting metabolic rate more directly, but most people do not need that level of testing. In practice, the best workflow is simple: start with a good estimate, track body-weight trends, watch energy and training performance, and then adjust.
If you are dieting and your scale trend is dropping faster than planned, raise calories slightly. If you are stuck for two to three weeks and food tracking is accurate, lower calories or increase activity a bit. That feedback loop matters more than the exact formula name on the page.
Compare your calorie estimate with other health and fitness tools to build a better nutrition plan.
Estimate maintenance calories by activity level.
Plan daily calories for loss, maintenance, or gain.
Estimate % of body fat and lean mass.
See weight category by WHO standards.
Convert between units.
Track precise age.
These answers match common People Also Ask searches around basal metabolic rate, resting metabolic rate, maintenance calories, and calorie deficits.
Use the Mifflin-St Jeor equation. For men, BMR = 10 x weight in kg + 6.25 x height in cm - 5 x age + 5. For women, BMR = 10 x weight in kg + 6.25 x height in cm - 5 x age - 161. After you get BMR, multiply it by your activity factor to estimate TDEE.
No. BMR is the energy your body needs at complete rest for basic functions like breathing and circulation. TDEE includes BMR plus movement, exercise, digestion, and daily activity. Your maintenance calories come from TDEE, not BMR alone.
Usually no. Most weight-loss plans work better when you create a moderate calorie deficit from your TDEE instead of eating below your BMR. Going too low can make training, recovery, and diet adherence harder, and it may increase the risk of muscle loss.
A BMR calculator gives you a useful estimate, not a lab measurement. The Mifflin-St Jeor equation is widely used because it performs well for many adults, but lean body mass, hormones, medications, and metabolic adaptation can still shift your real calorie burn.
There is no single ideal BMR for all women. A healthy adult woman may fall somewhere around 1200 to 1600 calories per day at rest, but age, height, weight, and muscle mass matter more than comparing your number to someone else's.
There is no universal target. Many adult men land roughly between 1500 and 2000 calories per day at rest, but your personal BMR depends on your body size, age, and lean mass. The more helpful number for planning meals is your TDEE.
Recalculate when your body weight changes by about 5 to 10 pounds, when your training schedule changes, or when your step count changes for several weeks. If your progress stalls for two to three weeks, update your estimate and compare it with your real intake.
Age can lower BMR over time, mostly because people often lose muscle and move less as they get older. Strength training, enough protein, and regular activity can help you protect lean body mass and reduce the drop in resting calorie burn.
You can often raise your resting calorie burn by building lean body mass, staying active, eating enough protein, sleeping well, and avoiding crash diets. The biggest long-term lever is usually more muscle, not short-term tricks or supplements.