Health
Calorie Calculator
Last updated: May 31, 2026
Written by Blake Boege
A calorie calculator is a nutritional tool that estimates the daily caloric intake required for a person to maintain, lose, or gain weight. It first calculates the Total Daily Energy Expenditure (TDEE) using metabolic formulas like the Mifflin-St Jeor equation, then applies a caloric deficit or surplus based on the user's weight management goals. It is the foundational tool for modern macronutrient and calorie-tracking diets.
Find how many calories you should eat per day based on your age, sex, weight, height, activity level, and weight goal. The calculator uses the Mifflin-St Jeor equation — the most accurate BMR formula for the general population — and shows your daily targets for weight loss, maintenance, and gain side-by-side so you can compare options.
Quick Answer
Calculate exactly how many calories you should eat per day to lose weight, gain muscle, or maintain your current weight based on your age, size, and activity level.
Sex
Units
Your daily calorie target
2,263 calories
to lose ~1 lb per week
All Goal Targets
Examples
25-year-old man, 180 lbs, 5'10", moderately active, maintain
~2,650 calories
35-year-old woman, 140 lbs, 5'4", lightly active, lose weight
~1,500 calories
45-year-old man, 200 lbs, 6'0", sedentary, lose weight
~2,100 calories
22-year-old woman, 125 lbs, 5'7", very active, gain muscle
~2,750 calories
How it works
The calculator runs in three steps:
- Calculate your BMR (Basal Metabolic Rate) — the calories your body burns at rest just keeping you alive. The Mifflin-St Jeor equation uses your weight, height, age, and biological sex to estimate this.
- Multiply BMR by your activity multiplier (1.2 for sedentary up to 1.9 for extra active) to get your TDEE (Total Daily Energy Expenditure) — your maintenance calories.
- Adjust TDEE based on your goal. A 500-calorie daily deficit produces about 1 lb of weight loss per week (3,500 calories ≈ 1 lb of fat). A 500-calorie daily surplus produces about 1 lb of gain per week.
Formulas
Men: BMR = (10 × weight in kg) + (6.25 × height in cm) − (5 × age) + 5
Women: BMR = (10 × weight in kg) + (6.25 × height in cm) − (5 × age) − 161
TDEE = BMR × activity multiplier
Daily calorie target = TDEE ± goal adjustment
Activity level guide
Choose the activity level that matches your weekly routine.
- Sedentary: Desk job, no formal exercise. Multiplier: 1.2
- Lightly active: Light exercise 1-3 days/week (walking, easy bike rides, light yoga). Multiplier: 1.375
- Moderately active: Moderate exercise 3-5 days/week (jogging, lifting, sports). Multiplier: 1.55
- Very active: Hard exercise 6-7 days/week (intense training, competitive sports). Multiplier: 1.725
- Extra active: Very hard exercise plus physical job or training 2x/day. Multiplier: 1.9
Most people overestimate their activity level. If you're not sure, pick one step lower than you think — it's easier to add calories later if you're losing weight too fast.
How to set your goal
For weight loss: a 500-calorie daily deficit gives about 1 lb of weight loss per week. This is the recommended pace — fast enough to see progress, slow enough to preserve muscle and energy. More aggressive deficits (1000+ cal/day) can work short-term but are harder to sustain and may slow metabolism.
For weight maintenance: eat at TDEE. Weight fluctuates day-to-day from water and food volume, so check weekly averages, not daily numbers.
For weight gain: a 250-500 calorie daily surplus supports lean muscle gain when combined with strength training. Larger surpluses cause more fat gain than muscle gain.
Recalculate every 10-15 lbs of weight change. Your calorie needs decrease as you lose weight.
Worked example
30-year-old woman, 150 lbs, 5'5" (165 cm), moderately active, wants to lose weight.
- Step 1: Convert weight: 150 lbs = 68 kg
- Step 2: BMR = (10 × 68) + (6.25 × 165) − (5 × 30) − 161
= 680 + 1031.25 − 150 − 161
= 1,400 calories/day - Step 3: TDEE = 1,400 × 1.55 (moderately active) = 2,170 calories/day
- Step 4: Weight loss target = 2,170 − 500 = 1,670 calories/day
She should eat about 1,670 calories per day to lose roughly 1 lb per week.
Common calorie calculation mistakes
- Overestimating activity level. Most people who pick 'moderately active' should actually pick 'lightly active.' If you have a desk job and work out 3x a week, you're 'lightly active,' not 'moderately active.'
- Ignoring weekly averages. Weight fluctuates 2-5 lbs day-to-day from water, sodium, food volume, and bowel movements. Track weekly averages instead of daily numbers.
- Not recalculating after weight change. Your calorie needs drop as you lose weight. A 200-lb person who reaches 170 lbs needs roughly 150-200 fewer daily calories. Recalculate every 10-15 lbs.
- Going too low too fast. Cutting more than 1000 calories below TDEE typically backfires — energy crashes, muscle loss, slowed metabolism, and rebound weight gain when you stop.
- Trusting calorie estimates as exact. The Mifflin-St Jeor formula is accurate within ±10% for most people. Track for 2-3 weeks and adjust based on actual results.
- Forgetting that "calories burned" estimates from fitness trackers are often inflated. Fitness watches overestimate exercise calorie burn by 25-50%. Use your TDEE target rather than 'eating back' exercise calories.
Related calculators
- TDEE Calculator for your maintenance calories.
- BMR Calculator for the calories you burn at complete rest.
- Calorie Deficit Calculator to plan a daily deficit and weight-loss timeline.
- Calories Burned Calculator for 100+ activities like walking, running, and cycling.
Disclaimer. This calorie calculator provides estimates based on the Mifflin-St Jeor equation. Individual calorie needs vary based on genetics, medications, body composition, and other factors not captured by the formula. Consult a registered dietitian or doctor for personalized nutrition advice, especially if you have a medical condition or are pregnant.
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Frequently asked questions
It depends on your age, sex, weight, height, activity level, and goals. As a rough average: sedentary women need 1,600-2,000 calories; active women 2,000-2,400; sedentary men 2,000-2,600; active men 2,400-3,000. Use the calculator above for your personalized number.
Mifflin-St Jeor is the most accurate BMR formula for the general population, with about 82% of non-obese individuals falling within ±10% of their measured BMR. It's the recommended formula by the American Dietetic Association. For very lean athletes who know their body fat percentage, the Katch-McArdle formula can be more accurate.
A daily 500-calorie deficit below your TDEE produces approximately 1 lb of weight loss per week (3,500 calories ≈ 1 lb of fat). Use the calculator above to see your specific weight-loss target.
Either you overestimated activity level (very common — most people should be one notch lower than they pick) or your goal deficit is too aggressive. For sustainable weight loss, a 500-calorie deficit is the sweet spot. Larger deficits typically backfire.
BMR (Basal Metabolic Rate) is the calories your body burns at complete rest — just keeping organs functioning. TDEE (Total Daily Energy Expenditure) is BMR plus all activity (exercise, walking, fidgeting, daily life). TDEE is what you eat to maintain weight; BMR is the foundation.
Generally no. Fitness trackers overestimate exercise calorie burn by 25-50%. Your activity multiplier already accounts for typical exercise. If you eat back inflated tracker calories, you'll wipe out your deficit. Better approach: pick your target from this calculator and stick to it regardless of daily exercise variation.
Possibly, but it's generally not recommended without medical supervision. Eating below 1,200 calories (women) or 1,500 calories (men) typically causes nutritional deficiencies, muscle loss, low energy, and rebound weight gain. Aim for a moderate deficit that keeps you above these floors.
Recalculate every 10-15 lbs of weight change, or when your activity level changes significantly, or if your weight loss/gain stalls for 2-3 weeks. Your calorie needs decrease as you lose weight (a 200-lb body burns more than a 150-lb body even at rest).
Men typically have more lean muscle mass than women at the same body weight, and muscle burns more calories at rest than fat. Men also tend to have higher testosterone, which supports metabolism. The Mifflin-St Jeor formula accounts for this with a sex-specific constant (+5 for men, -161 for women).
Yes, if you selected the correct activity level. The activity multiplier (1.2 to 1.9) accounts for both daily activity and exercise. You don't need to separately add exercise calories on top of your target — the activity level you picked already includes it.
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