How to use the calorie Calculator (TDEE)
- Choose your sex and enter your age.
- Choose metric or imperial units and enter your weight and height.
- Pick the activity level that best describes a typical week. If unsure, choose the lower one.
- The result updates instantly as you type. There is no button to press.
- Use Copy result to copy the figures, or Copy link to share a link that reopens the calorie Calculator (TDEE) with the same inputs.
How it works
Your total daily energy expenditure (TDEE) is the number of calories you burn in a typical day. It is the calorie intake that would keep your weight stable, often called your maintenance calories. Eat less than this and your body draws on stored energy, so you lose weight. Eat more and the surplus is stored, so you gain weight.
The calculator estimates TDEE in two steps. First it works out your basal metabolic rate with the Mifflin-St Jeor equation, the calories needed at complete rest. Then it multiplies that by an activity factor that accounts for exercise, daily movement and the energy used to digest food. These factors, from 1.2 for a desk-bound lifestyle to 1.9 for heavy physical work plus training, are the standard multipliers used by dietitians.
A deficit of about 500 kcal a day is a commonly recommended starting point for steady fat loss of roughly 0.45 kg (1 lb) a week, based on the rule of thumb that a kilogram of body fat stores about 7,700 kcal. Real-world results vary: as you lose weight your TDEE falls, and water shifts can hide progress for a week or two. Track your weight for 2–3 weeks and adjust by 100–200 kcal if the trend does not match your goal.
Formula
W is weight in kg, H height in cm and A age. Activity factors: 1.2, 1.375, 1.55, 1.725 or 1.9.
Example
A 30-year-old man, 70 kg and 175 cm, has a BMR of about 1,649 kcal. Exercising 3–5 days a week (factor 1.55), his TDEE is 1,649 × 1.55 ≈ 2,556 kcal a day. Eating about 2,056 kcal a day, a 500 kcal deficit, would be expected to take off roughly 0.45 kg a week at first. To gain muscle slowly he might eat around 2,806 kcal.
Frequently asked questions
Which activity level should I choose?
Most people overestimate their activity. If you have a desk job and train three times a week, 'Light' or 'Moderate' is usually accurate. You can fine-tune using your actual weight trend over a few weeks.
Why am I not losing weight on a deficit?
Common reasons are underestimating portion sizes, water retention masking fat loss, or a TDEE that is lower than estimated. Weigh yourself regularly and look at the average over 2–3 weeks.
Is it safe to eat 1,000 calories below TDEE?
Large deficits can cause muscle loss, fatigue and nutrient gaps, and very low intakes should only be followed with medical supervision. A deficit of 10–20% of TDEE is a more sustainable starting point for most people.
Do I need to count exercise calories separately?
No. The activity factor already includes your typical exercise. Adding exercise calories on top would count them twice.
Disclaimer: This calculator provides general estimates for education only and is not medical advice, diagnosis or treatment. Formulas are based on population averages and may not fit your body, age, pregnancy or health conditions. Talk to a doctor, midwife or registered dietitian before making decisions about your health.