🥗 Calorie Calculator

Calculate your BMR and daily calorie needs using the Mifflin-St Jeor or Harris-Benedict formula. Get maintenance, weight loss, and weight gain targets with macro breakdowns.

Free Mifflin-St Jeor Metric & Imperial

Your Details

yrs
ft
in
cm

lbs
kg

Activity Level
Formula

🔥

BMR

Your resting metabolic rate — calories burned at complete rest

⚡

TDEE

Total Daily Energy Expenditure — actual daily calorie burn

🎯

7 Goals

From extreme weight loss to fast muscle gain

🥗

Macros

Protein, carbs & fat split for cutting, maintaining, bulking

🍽

Meal Plans

3, 5 or 6 meal-per-day distribution

📐

BMI + Ideal Wt

Body Mass Index & healthy weight range for your height

📐 How Calorie Needs Are Calculated

Mifflin-St Jeor (♂): BMR = 10×W + 6.25×H − 5×A + 5

Mifflin-St Jeor (♀): BMR = 10×W + 6.25×H − 5×A − 161

TDEE = BMR × Activity Multiplier (1.2 – 1.9)

W=weight(kg), H=height(cm), A=age(yrs)

Mifflin-St Jeor, activity multipliers and the macro split

Basal metabolic rate is the energy your body uses at complete rest. The default equation is Mifflin-St Jeor, published in 1990 and generally regarded as the more accurate of the two for modern populations. For men, BMR equals 10 times weight in kilograms, plus 6.25 times height in centimetres, minus 5 times age in years, plus 5. For women the final term is minus 161 instead of plus 5. The Harris-Benedict option uses the older revised equation, which typically returns a slightly higher figure.

Total daily energy expenditure is BMR multiplied by an activity factor: 1.2 for sedentary, 1.375 for lightly active, 1.55 for moderately active, 1.725 for very active and 1.9 for extra active.

Goal targets adjust TDEE by a fixed daily amount: minus 1000, minus 500, minus 250, zero, plus 250, plus 500 or plus 1000 calories, floored at 1200. Macros use fixed percentage splits of the target calories, 30 protein, 40 carbohydrate and 30 fat for maintenance, then converted to grams at 4 calories per gram for protein and carbohydrate and 9 for fat.

A worked example for a 30-year-old man

Take a man aged 30, 180 cm tall, weighing 80 kg, moderately active, using Mifflin-St Jeor.

BMR: 10 times 80 is 800; 6.25 times 180 is 1,125; 5 times 30 is 150. So 800 plus 1,125 equals 1,925, minus 150 equals 1,775, plus 5 equals 1,780 calories per day at rest.

TDEE: 1,780 multiplied by the moderately active factor of 1.55 gives 2,759 calories per day.

Goals: maintenance is 2,759. The standard weight loss target subtracts 500, giving 2,259 and implying roughly one pound a week. Weight gain adds 500 for 3,259.

Macros at maintenance, using the 30/40/30 split of 2,759 calories: protein is 30 percent, which is 828 calories, divided by 4, giving 207 g. Carbohydrate is 40 percent, 1,104 calories, divided by 4, giving 276 g. Fat is 30 percent, 828 calories, divided by 9, giving 92 g.

BMI: 80 divided by 1.8 squared. 1.8 squared is 3.24, and 80 divided by 3.24 is 24.7, which falls in the normal category, just under the 25 threshold.

Using the numbers sensibly, and where they go wrong

These equations are population averages fitted to large samples. Individual metabolic rates vary by roughly plus or minus ten percent around the prediction, and more in people who are very muscular or very lean, because the formulas use total body weight rather than lean mass. Treat your figure as a starting point, then adjust: track intake and weight for two to three weeks and move your target by 100 to 200 calories if the trend is not what you intended.

Activity level is the biggest source of error, and people routinely overestimate it. The multiplier is meant to cover your whole week, including a desk job, not just the days you train. If in doubt, pick one level lower than feels right and compare the activity table.

The deficit shortcuts assume roughly 3,500 calories per pound of body weight, which is an approximation that holds less well over long periods as metabolism adapts. The calculator floors any target at 1,200 calories for that reason.

This is general information only. Consult a doctor or registered dietitian before making significant dietary changes, particularly if you are pregnant, under 18, or managing a medical condition.

Frequently Asked Questions

Mifflin-St Jeor is the default and is generally considered more accurate for the general population. Harris-Benedict is the older revised equation and usually returns a slightly higher basal rate. The calculator shows both so you can compare, but pick one and stay with it when tracking progress.
BMR is the energy your body would use lying still all day, covering breathing, circulation and organ function. TDEE is BMR multiplied by an activity factor between 1.2 and 1.9, so it includes movement, exercise and the energy cost of digesting food. TDEE is the number to eat towards.
Choose the level that describes your whole week, not your best day. Sedentary means a desk job with little exercise, lightly active means one to three sessions a week, moderately active three to five, very active six to seven, and extra active adds a physically demanding job. Most people overestimate.
The target calories are split by fixed percentages, then converted using 4 calories per gram for protein and carbohydrate and 9 per gram for fat. Maintenance uses 30 percent protein, 40 carbohydrate and 30 fat; the cutting preset raises protein to 35 percent and lowers fat to 25.
No. It is general information based on published predictive equations, and individual results vary by around ten percent or more. Speak to a doctor or registered dietitian before making significant changes, especially if you are pregnant, under 18, or managing a medical condition.