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Calorie Calculator

Calculate your daily calorie needs (BMR & TDEE) using the Mifflin-St Jeor equation

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cm

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Quick summary

This calculator estimates your daily calorie needs with the Mifflin-St Jeor equation, the BMR formula the Academy of Nutrition and Dietetics recommends for healthy adults. It multiplies your BMR by an activity factor to get TDEE (your maintenance calories), then adds or subtracts 250–1,000 calories for your goal, never going below 1,200 a day. Treat the result as a starting estimate and adjust based on real progress.

Reviewed by Simple Calculators TeamLast reviewed

For information only — not medical advice. Results are estimates from published formulas and can't account for your health history. Talk to a doctor or other qualified clinician before making health decisions.

How to use this calculator

  1. Pick your unit system (Metric for kg and cm, or Imperial for lbs and inches) and your biological sex; switching units converts what you have entered.
  2. Enter your Age, Weight, and Height in the units you selected.
  3. Choose the Activity Level that matches a typical week, from Sedentary (×1.2) to Extra Active (×1.9); if unsure, pick the lower option.
  4. Choose a Goal, from Lose 2 lbs/week to Gain 1 lb/week, or Maintain weight.
  5. Click Calculate Calories, then read BMR (calories at rest), TDEE (maintenance), Target Calories for your goal, and the suggested macro and meal split. Recheck your weight after 2–4 weeks and adjust.

BMR & TDEE Formulas

BMR — Mifflin-St Jeor (Male)

BMR=(10×w)+(6.25×h)−(5×a)+5BMR = (10 \times w) + (6.25 \times h) - (5 \times a) + 5
w
Weight in kilograms
h
Height in centimeters
a
Age in years

Worked example

30-year-old male, 80 kg, 180 cm

Given
w = 80 kg
h = 180 cm
a = 30 years
Calculation
BMR=(10×80)+(6.25×180)−(5×30)+5BMR = (10 \times 80) + (6.25 \times 180) - (5 \times 30) + 5
Result
BMR = 800 + 1125 − 150 + 5 = 1,780 kcal/day

BMR — Mifflin-St Jeor (Female)

BMR=(10×w)+(6.25×h)−(5×a)−161BMR = (10 \times w) + (6.25 \times h) - (5 \times a) - 161
w
Weight in kilograms
h
Height in centimeters
a
Age in years

Worked example

28-year-old female, 65 kg, 165 cm

Given
w = 65 kg
h = 165 cm
a = 28 years
Calculation
BMR=(10×65)+(6.25×165)−(5×28)−161BMR = (10 \times 65) + (6.25 \times 165) - (5 \times 28) - 161
Result
BMR = 650 + 1031.25 − 140 − 161 = 1,380 kcal/day

TDEE (Total Daily Energy Expenditure)

TDEE=BMR×Activity MultiplierTDEE = BMR \times \text{Activity Multiplier}
BMR
Basal Metabolic Rate
Activity Multiplier
Sedentary 1.2 → Extra active 1.9

Worked example

Moderately active person with BMR of 1,780

Given
BMR = 1,780 kcal
Multiplier = 1.55 (moderately active)
Calculation
TDEE=1780×1.55TDEE = 1780 \times 1.55
Result
TDEE = 2,759 kcal/day

Daily Calorie Target

Target=max⁡(1200, TDEE+Goal Adjustment)\text{Target} = \max(1200,\ TDEE + \text{Goal Adjustment})
TDEE
Total Daily Energy Expenditure (maintenance calories)
Goal Adjustment
−1,000, −500 or −250 kcal to lose; 0 to maintain; +250 or +500 kcal to gain
1200
Minimum target the calculator will show, in kcal/day

Worked example

28-year-old female, 65 kg, 165 cm, lightly active, goal: lose 1 lb/week

Given
BMR = 1,380 kcal
Multiplier = 1.375 (lightly active)
Goal Adjustment = −500 kcal
Calculation
TDEE=1380×1.375=1897.5≈1898;Target=max⁡(1200, 1898−500)TDEE = 1380 \times 1.375 = 1897.5 \approx 1898;\quad \text{Target} = \max(1200,\ 1898 - 500)
Result
Target = 1,398 kcal/day

Frequently asked questions

What is BMR?

Basal metabolic rate (BMR) is the number of calories your body burns at complete rest to keep basic functions running, such as breathing, circulation, and cell repair. It is the minimum energy your body needs each day. This calculator estimates BMR with the Mifflin-St Jeor equation from your sex, age, weight, and height, then builds your other numbers on top of it.

What is TDEE?

Total daily energy expenditure (TDEE) is the total number of calories you burn in a day, including all activity. The calculator finds it by multiplying your BMR by an activity factor: 1.2 for sedentary, 1.375 lightly active, 1.55 moderately active, 1.725 very active, and 1.9 extra active. Eating at your TDEE should roughly maintain your current weight.

How is my daily calorie target calculated?

Your target is your TDEE plus a goal adjustment, with a floor of 1,200 calories a day. The adjustments are −1,000 (lose 2 lbs/week), −500 (lose 1 lb/week), −250 (lose 0.5 lb/week), 0 (maintain), +250 (gain 0.5 lb/week), and +500 (gain 1 lb/week). For example, a TDEE of 1,898 with a lose-1-lb goal gives a target of 1,398 calories a day.

How accurate is the Mifflin-St Jeor equation?

Mifflin-St Jeor is widely regarded as the most reliable of the common BMR prediction equations for healthy adults, but it is still an estimate. Your real metabolism can differ because of muscle mass, genetics, medical conditions, and medications. Use the result as a starting point, track your weight for a few weeks, and adjust intake if your weight is not moving as expected.

How many calories should I cut to lose weight?

A common starting point is about 500 calories a day below your TDEE, which by the rough 3,500-calories-per-pound rule of thumb works out to about 1 lb a week. Real weight loss usually slows over time as your body adapts. General guidance is not to go below about 1,200 calories a day for women or 1,500 for men without medical supervision.

Why is my calorie target never below 1,200?

The calculator never shows a target below 1,200 calories a day, because very low intakes make it hard to meet nutrient needs and are generally advised only under medical supervision. If your TDEE minus your goal adjustment falls below that, the target is raised to 1,200, so the weekly loss you see may not actually be reached. A doctor or registered dietitian can advise on lower targets.

How are the macros and meals split?

The calculator splits your target calories into 30% protein, 40% carbohydrates, and 30% fat, a balanced general-purpose split. Grams are calculated at 4 calories per gram for protein and carbs and 9 per gram for fat. Meals are divided into breakfast 25%, lunch 35%, dinner 30%, and snacks 10%. Adjust these to your preferences or a dietitian's advice.

Who should not rely on this calorie calculator?

This calculator is designed for healthy adults and accepts ages 15 to 80; it is not suited to pregnancy, breastfeeding, children, or people managing a medical condition. Very muscular people may also get an underestimate, because the formula does not account for body composition. In any of these cases, or if you have a history of disordered eating, talk to a doctor or registered dietitian.

Key terms

BMR
Basal Metabolic Rate — calories burned at complete rest.
TDEE
Total Daily Energy Expenditure — total calories burned including activity.
Calorie Deficit
Eating fewer calories than you burn, leading to weight loss.
Calorie Surplus
Eating more calories than you burn, leading to weight gain.
Macronutrients
The three main nutrients providing calories: protein (4 kcal/g), carbohydrates (4 kcal/g), and fat (9 kcal/g).

Methodology, sources & limitations

This page shows the formula, assumptions, and limitations used for this estimate. Rates, thresholds, and other time-sensitive inputs can change, so verify them against the relevant official source before relying on a result.

For our review approach and the primary sources we consult, see the methodology and source policy. If you spot an outdated figure or formula, please contact us with a correction.