Calorie Calculator (TDEE)
Estimate your daily calorie needs for maintaining, losing or gaining weight — using the well-validated Mifflin-St Jeor equation and your activity level.
2026 rates · Last reviewed: 2026
How your calorie needs are estimated
This calculator uses the Mifflin-St Jeor equation — widely regarded as one of the most accurate for the general population — to estimate your BMR (the energy you burn at rest). It then multiplies that by an activity factor to get your TDEE: roughly how many calories you burn in a full day.
What each input means
- Age, sex, height, weight — the inputs the Mifflin-St Jeor equation uses to estimate your resting burn (BMR).
- Activity level — multiplies your BMR to reflect how active your whole week is, turning BMR into TDEE.
- Goal — maintain, lose, or gain; this shifts your daily target above or below your TDEE.
- Units — switch between metric (kg/cm) and imperial (lb/in); the result is the same either way.
Activity levels explained
Your TDEE is your BMR multiplied by an activity factor. The standard multipliers are:
| Activity level | Multiplier |
|---|---|
| Sedentary (little or no exercise) | ≈ 1.2 |
| Lightly active (1–3 days/week) | ≈ 1.375 |
| Moderately active (3–5 days/week) | ≈ 1.55 |
| Very active (6–7 days/week) | ≈ 1.725 |
| Extra active (hard training / physical job) | ≈ 1.9 |
Eating for your goal
To maintain your weight, eat around your TDEE. To lose weight, eat a little below it; to gain, a little above. A deficit of about 500 calories a day points toward roughly a pound a week.
Use it as a starting point
These are estimates. Bodies vary, and the real test is what happens over a few weeks. Track the trend and adjust gently. For more, see how many calories to lose weight and BMR vs TDEE.
Worked example
Suppose a 30-year-old woman, 165 cm tall, weighing 65 kg. The Mifflin-St Jeor equation gives a BMR of about 1,370 calories a day (10 × 65 + 6.25 × 165 − 5 × 30 − 161). If she's moderately active, her TDEE is roughly 1,370 × 1.55 ≈ 2,120 calories a day to maintain her weight. To lose about a pound a week she'd aim for roughly 1,600 calories. These numbers are an illustration — your own figures will differ.
Key terms
- BMR — basal metabolic rate: the calories your body burns at complete rest.
- TDEE — total daily energy expenditure: BMR plus everything else you do in a day.
- Calorie (kcal) — the unit of food energy shown on nutrition labels.
- Deficit / surplus — eating below TDEE (to lose) or above it (to gain).
- Maintenance — eating at your TDEE so your weight stays steady.
- Macronutrients — protein, carbohydrate and fat, the three sources of calories.
Common misunderstandings
- "Fewer calories is always better." Very low intake costs muscle and energy and rarely lasts; a moderate deficit works better.
- Overestimating activity. Most people pick too high a level — when unsure, choose the lower one.
- Expecting the scale to move daily. Water and food weight fluctuate; judge by the multi-week trend.
- Treating the number as exact. It's a well-founded estimate, not a precise measurement — adjust based on real results.
An important note
This tool is general information, not medical or nutritional advice, and isn't suitable for children, pregnant or nursing people, or anyone managing a health condition or eating disorder. If food and weight feel stressful, please reach out to a doctor or a qualified professional for support.
Frequently asked questions
How many calories should I eat a day?
It depends on your age, sex, height, weight and activity level. This calculator estimates your TDEE — the calories you burn in a typical day — so you can eat at that level to maintain, below it to lose, or above it to gain weight. Your personal number is far more useful than any average.
What is TDEE?
TDEE (Total Daily Energy Expenditure) is all the calories you burn in a day: your resting burn (BMR) multiplied by an activity factor. This calculator works out both steps for you based on the activity level you select.
How many calories should I eat to lose weight?
Eat about 500 calories a day below your TDEE for a safe loss of roughly 0.5 kg (1 lb) per week. Read how many calories to lose weight for a practical approach, and avoid dropping below your BMR.
Which activity level should I choose?
Pick the level that reflects your whole week: sedentary for desk jobs, lightly active for 1–3 workouts weekly, moderately active for 3–5, very active for hard training most days. Most people overestimate, so choose the lower option if unsure.
Do I eat back calories burned during exercise?
If your chosen activity level already includes exercise, no — those calories are in your TDEE and eating them back would double-count. Only add them separately if you selected a sedentary level and track workouts on their own.
What's the difference between BMR and TDEE?
BMR is the energy your body uses at complete rest just to stay alive. TDEE is your BMR plus the calories you burn moving, exercising and digesting food — it's the number that reflects a real day. This calculator estimates BMR first, then scales it by your activity level to get TDEE.
How accurate are calorie estimates?
Equations like Mifflin-St Jeor are accurate for most people within a modest margin, but real metabolism varies with genetics, muscle mass and other factors. Treat the number as a well-founded starting point and fine-tune it based on how your weight actually responds over a few weeks.
Should I eat below my BMR to lose faster?
Generally no. Eating below your BMR for long stretches can cost muscle, sap energy and be hard to sustain. A moderate deficit below your TDEE is safer and more effective. If you have specific medical goals, speak to a doctor or dietitian.
This calculator provides estimates for general information only and is not medical advice. See our disclaimer.