Calorie Calculator
Calculate your daily calorie needs (TDEE) based on age, height, weight, sex, and activity level.
Units:
Sex:
Activity level:
Little or no exercise, desk job
| Goal | Calories / day |
|---|---|
| BMR (at rest) | — kcal |
| Maintenance (TDEE) | — kcal |
| Mild weight loss (−250 kcal) | — kcal |
| Weight loss (−500 kcal) | — kcal |
| Weight gain (+300 kcal) | — kcal |
Your daily calorie needs depend on two things: how much energy your body burns at rest (BMR) and how much you move. This calculator uses the Mifflin-St Jeor equation — the most accurate predictive formula for most adults — to estimate both your BMR and your Total Daily Energy Expenditure (TDEE).
When do you need this?
- Starting a fat-loss plan and wanting a calorie target grounded in your actual stats rather than a generic "1,200 calories" rule.
- Eating at maintenance during a muscle-building phase to avoid excessive fat gain.
- Recovering from illness or surgery and needing to ensure adequate energy intake.
- Athletes in training who need to scale calories up as their activity level increases.
- Checking whether a diet plan's prescribed calories are reasonable for your size and activity level.
- Understanding why your calorie needs have changed as you age or after a significant weight change.
Quick reference
- Mifflin-St Jeor (men): BMR = (10 × weight kg) + (6.25 × height cm) − (5 × age) + 5
- Mifflin-St Jeor (women): BMR = (10 × weight kg) + (6.25 × height cm) − (5 × age) − 161
- TDEE: BMR × activity factor (1.2 sedentary → 1.9 very active)
- Weight loss: TDEE − 500 kcal/day ≈ 0.5 kg (1 lb) per week
- Weight gain / muscle building: TDEE + 200–300 kcal/day
- 1 kg of body fat ≈ 7,700 kcal
Typical daily calorie needs — reference table
| Profile | BMR (approx.) | Sedentary TDEE | Moderate TDEE |
|---|---|---|---|
| Woman, 30 y, 165 cm, 65 kg | 1,444 kcal | 1,733 kcal | 2,238 kcal |
| Man, 30 y, 178 cm, 80 kg | 1,820 kcal | 2,184 kcal | 2,821 kcal |
| Woman, 50 y, 165 cm, 70 kg | 1,394 kcal | 1,673 kcal | 2,161 kcal |
| Man, 50 y, 178 cm, 85 kg | 1,770 kcal | 2,124 kcal | 2,744 kcal |
| Woman, 25 y, 160 cm, 55 kg | 1,344 kcal | 1,613 kcal | 2,083 kcal |
| Man, 25 y, 183 cm, 90 kg | 1,980 kcal | 2,376 kcal | 3,069 kcal |
Understanding the concepts
BMR — Basal Metabolic Rate
BMR is the number of calories your body needs to sustain basic life functions at complete rest — breathing, circulation, cell maintenance, and temperature regulation. It accounts for 60–75% of total calorie expenditure for most sedentary people. BMR is driven primarily by your lean mass, height, age, and sex.
TDEE — Total Daily Energy Expenditure
TDEE is BMR multiplied by an activity factor that accounts for exercise and daily movement. A sedentary office worker uses a factor of 1.2; someone training hard six days a week uses 1.725. TDEE is the number you need to hit to maintain your current weight — eat less and you lose, eat more and you gain.
Activity factors explained
The five activity levels used here are: Sedentary (1.2) — desk job, little exercise; Light (1.375) — light exercise 1–3 days/week; Moderate (1.55) — moderate exercise 3–5 days/week; Active (1.725) — hard exercise 6–7 days/week; Very active (1.9) — physical job plus daily training. When in doubt, pick the level below what you think you are — people consistently overestimate their activity.
Calories vs. kilocalories
In everyday nutrition, "calorie" always means kilocalorie (kcal). Food labels worldwide use kcal, though they often just print "Calories" (capital C) or "Cal". This calculator outputs kcal throughout — the same unit used on food packaging in virtually every country.
Common mistakes
- Overestimating activity level. Most people who exercise 3–4 times a week are "Moderate" at best, not "Active". Choosing the wrong level inflates your TDEE estimate and causes unintended weight gain.
- Using TDEE as a rigid daily target. Energy expenditure varies day to day. TDEE is a weekly average — aim for it as a seven-day mean, not an exact daily number.
- Treating the output as exact. Mifflin-St Jeor is accurate within ±10% for most people. Individual metabolic variation, hormones, and sleep quality all affect actual expenditure in ways no formula can capture.
- Ignoring protein when cutting calories. Eating at a 500 kcal deficit without adequate protein (1.6–2.2 g/kg) leads to muscle loss alongside fat loss, lowering BMR over time.
- Recalculating too infrequently. As your weight changes, so does your BMR and TDEE. Recalculate every 4–6 weeks or after a weight change of more than 5 kg.
Which calorie target should you use?
Maintaining weight: Eat at your TDEE. Track for 2–4 weeks and adjust by 100–200 kcal if your weight is drifting in the wrong direction.
Losing fat: A 400–600 kcal deficit is sustainable for most people. Larger deficits accelerate scale loss short-term but increase muscle loss and the risk of rebound. Avoid going below 1,200 kcal (women) or 1,500 kcal (men).
Building muscle: A surplus of 200–300 kcal above TDEE is enough for most people. More than this typically adds fat without meaningfully increasing muscle gain unless you are a complete beginner.
Athlete or very active: Use the 1.725 or 1.9 multiplier and monitor performance. Endurance athletes in heavy training may need 3,000–4,500+ kcal per day.
Frequently asked questions
How many calories should I eat per day?
It depends on your age, height, weight, sex, and activity level. A sedentary adult woman typically needs around 1,600–2,000 kcal per day; a sedentary adult man around 2,000–2,400 kcal. Active people need considerably more. This calculator gives a personalised estimate using the Mifflin-St Jeor equation.
What is TDEE and why does it matter?
TDEE stands for Total Daily Energy Expenditure — the total calories your body burns each day including rest and all activity. Eating at your TDEE maintains your weight. Eating below it causes weight loss; eating above it causes weight gain. It is the single most useful number to know when managing body composition.
What is BMR and how is it different from TDEE?
BMR (Basal Metabolic Rate) is the calories your body burns at complete rest — breathing, circulation, cell repair. TDEE multiplies BMR by an activity factor to account for daily movement. Most people's TDEE is 1.2 to 1.9 times their BMR.
How many calories should I eat to lose weight?
A deficit of 500 kcal per day below your TDEE produces roughly 0.5 kg (1 lb) of weight loss per week. Most guidelines recommend not going below 1,200 kcal/day for women or 1,500 kcal/day for men without medical supervision, as very low intake can cause nutrient deficiencies and muscle loss.
Is the Mifflin-St Jeor equation accurate?
Mifflin-St Jeor is the most widely validated predictive equation for BMR in modern clinical use. A 2005 study found it accurate within 10% for most people. No formula accounts for individual metabolic variation, muscle mass, hormonal factors, or genetics — treat the result as a starting estimate and adjust after 2–4 weeks of tracking.
How many calories do I need to build muscle?
Building muscle requires a modest calorie surplus — typically 200–300 kcal above your TDEE. A larger surplus increases fat gain without meaningfully accelerating muscle growth for most people. Protein intake of 1.6–2.2 g per kg of bodyweight matters more than total calories for muscle synthesis.
Related tools
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