Calorie Calculator (TDEE & BMR)
Last Updated:
Calculate your Total Daily Energy Expenditure (TDEE) and Basal Metabolic Rate (BMR) using the Mifflin-St Jeor equation — the gold standard formula.
🔥 Calorie Calculator (TDEE & BMR)
Results update instantly
How to Use the Calorie Calculator
Enter your age, sex, height, and weight
These four inputs determine your BMR using the Mifflin-St Jeor formula — the most validated equation for estimating resting calorie burn for most adults.
Select your activity level
Choose the level that reflects your typical week, not your best week. Most office workers are sedentary to lightly active even if they exercise 2–3 times per week.
Select your goal
Choose lose weight (500 calorie deficit), maintain, or gain weight (300–500 calorie surplus). The calculator adjusts your daily target accordingly.
Use the result as a starting point
Track intake vs weight change over 2–3 weeks. If weight is not moving as expected, adjust your calorie target by 100–200 calories. Individual metabolic rates vary ±10% from formula predictions.
How Daily Calorie Needs Are Calculated
This calculator uses the Mifflin-St Jeor equation (1990), considered the most accurate BMR formula for most adults. BMR (Basal Metabolic Rate) is the calories your body burns at complete rest. TDEE (Total Daily Energy Expenditure) multiplies BMR by an activity factor.
📐 Mifflin-St Jeor Formula
BMR = 10(75) + 6.25(175) − 5(30) + 5 = 1,755 cal
TDEE = 1,755 × 1.55 = 2,720 cal/day
How Are Daily Calorie Needs Calculated?
Daily calorie needs are calculated in two steps: first your Basal Metabolic Rate (BMR) — the calories needed at complete rest — then multiplied by an activity factor to get your Total Daily Energy Expenditure (TDEE). This calculator uses the Mifflin-St Jeor equation, which is considered the most accurate formula for most adults by the Academy of Nutrition and Dietetics.
Male BMR: (10 × weight kg) + (6.25 × height cm) − (5 × age) + 5
Female BMR: (10 × weight kg) + (6.25 × height cm) − (5 × age) − 161
Activity Multipliers Explained
| Activity Level | Multiplier | Example |
|---|---|---|
| Sedentary | ×1.2 | Desk job, little or no exercise |
| Lightly active | ×1.375 | Light exercise 1–3 days/week |
| Moderately active | ×1.55 | Moderate exercise 3–5 days/week |
| Very active | ×1.725 | Hard exercise 6–7 days/week |
| Extremely active | ×1.9 | Physical job + hard training daily |
How Many Calories to Lose Weight?
One pound of fat contains approximately 3,500 calories. To lose 1 lb per week, create a daily deficit of 500 calories (500 × 7 = 3,500). For 2 lbs/week, a 1,000 calorie/day deficit. However, never go below 1,200 calories/day (women) or 1,500 calories/day (men) without medical supervision — this risks nutritional deficiencies and muscle loss.
Calories to Gain Muscle
Building muscle requires a calorie surplus — typically 200–500 calories above TDEE. Combined with adequate protein (0.7–1g per pound of bodyweight) and progressive resistance training, a moderate surplus supports muscle growth while minimising fat gain. A "dirty bulk" with large surpluses adds mostly fat; a "lean bulk" with 200–300 calories above TDEE is more efficient.
What is the Best Diet for Weight Loss?
Research consistently shows that total calorie deficit matters more than macronutrient composition for weight loss. Whether low-carb, low-fat, Mediterranean, or intermittent fasting — adherence to a sustainable calorie deficit is the determining factor. Protein intake (at least 0.7g/lb bodyweight) is important for preserving muscle during weight loss. Use our Macro Calculator to set protein, carb, and fat targets.
How to Calculate a Calorie Deficit for Weight Loss by Hand: Worked Example
Continuing from the BMR of 1,742.5 calories (35-year-old male, 80 kg, 178 cm) with a moderate activity multiplier of 1.55: TDEE = 1,742.5 × 1.55 = 2,701 calories/day — the estimated maintenance calorie level at current weight and activity.
Target for roughly 1 lb/week loss: one pound of body fat represents approximately 3,500 stored calories, so a 500-calorie daily deficit (3,500 ÷ 7 days) produces roughly that rate: 2,701 − 500 = 2,201 calories/day.
Target for roughly 2 lb/week loss: 2,701 − 1,000 = 1,701 calories/day. This aggressive a deficit frequently falls below commonly cited minimum intake guidelines for adult men (often cited around 1,500–1,800 calories) and can be difficult to sustain — most dietitians recommend the more moderate 500-calorie deficit as a sustainable default unless working directly with a healthcare provider.
Why does the "3,500 calories per pound" rule become less accurate over a long diet?
The 3,500-calorie estimate assumes a static metabolic rate, but BMR itself typically declines somewhat as body weight drops (a smaller body requires less energy) — a phenomenon sometimes called metabolic adaptation. This is why weight loss often slows during an extended diet even with a consistent calorie deficit maintained on paper, and why recalculating TDEE periodically as weight changes keeps the target realistic.
Is There a "Best" Diet Approach Once Calories Are Set?
Does the source of calories matter once the total is fixed?
For pure weight change, total calorie balance is the primary driver — a calorie deficit produces weight loss regardless of whether it comes from carbs, fat, or protein. However, macronutrient composition strongly affects hunger, muscle retention, and long-term adherence: diets that are too low in protein during a deficit risk losing more muscle mass alongside fat, which is why many calorie targets are paired with a macro breakdown (see the macro calculator) rather than a calorie number alone.
How much muscle mass affects the calorie calculation itself?
Muscle tissue burns more calories at rest than fat tissue, so two people at an identical weight and height can have meaningfully different actual BMR depending on body composition — a limitation the Mifflin-St Jeor formula (based on weight, height, age, and sex alone) cannot fully capture, which is one reason calculated TDEE is a starting estimate to adjust from, not a fixed, guaranteed number.
Should you eat back calories burned during exercise?
The activity multiplier in the TDEE calculation already accounts for a general activity level, so deliberately "eating back" additional calories for a workout already reflected in that multiplier can create an unintended surplus. This matters most for people using fitness trackers that separately estimate workout calories on top of an activity-adjusted TDEE — double-counting activity is a common source of stalled weight loss despite an apparently correct calorie deficit on paper.
Frequently Asked Questions
Sources & Methodology
Calculations are based on the most current publicly available data from authoritative government and industry sources: