About this calculator
Your total daily energy expenditure (TDEE) is how many calories your body actually burns in a day: the energy to simply exist (your basal metabolic rate, BMR) plus everything you do on top of it. Eat at TDEE and your weight holds steady; eat below it and you lose; above it, you gain. It is the most useful single number in nutrition, and the starting point for any diet that is based on math rather than hope.
This calculator uses the Mifflin-St Jeor equation, which studies have found to be the most accurate of the common BMR formulas for the general population — typically within about 10%. Even so, treat the output as a well-informed estimate: track your weight trend for two to three weeks at the suggested intake and adjust by 100–200 calories if the trend disagrees.
How to use it
- Enter your sex, age, weight and height.
- Pick the activity level that matches a normal week, not your best week — most people overestimate this.
- Choose your goal to see the target intake, and use the table to see how activity changes the picture.
The formula
Mifflin-St Jeor estimates resting burn from weight, height, age and sex. Multiplying by 1.2 (sedentary) up to 1.9 (athlete) accounts for daily movement and exercise. A pound of body fat stores roughly 3,500 kcal, which is why a daily ±500 kcal adjustment maps to about a pound a week.
Worked example
A 30-year-old man at 80 kg and 180 cm has a BMR of 1,780 kcal. With a moderately active lifestyle (×1.55) his TDEE is 2,759 kcal a day: eat about that to maintain, about 2,259 to lose roughly a pound a week, about 3,259 to gain at the same pace. A 30-year-old woman at 65 kg and 165 cm has a BMR of 1,370 kcal — activity level alone swings her needs by nearly 1,000 kcal between sedentary and athlete.
Frequently asked questions
How accurate is a TDEE calculator?
Expect roughly ±10%. The formulas estimate averages for people of your size and age; individual metabolisms, muscle mass and — biggest of all — how active you truly are can shift real needs by a few hundred calories. The fix is empirical: hold the suggested intake for 2–3 weeks, watch the weight trend, and adjust in 100–200 kcal steps.
How many calories should I eat to lose weight?
A deficit of 300–500 kcal below TDEE is the standard sustainable range, giving about 0.5–1 lb (0.25–0.5 kg) of loss per week. Faster is rarely better: aggressive deficits cost muscle, energy and adherence. Keep protein up (see our Macro Calculator) to protect muscle while you cut.
What is the minimum safe calorie intake?
Common clinical guidance is not to go below about 1,200 kcal/day for women or 1,500 kcal/day for men without medical supervision — below that it becomes hard to cover basic nutrient needs. If your calculated target falls below those floors, widen the timeline instead of the deficit.
Why did my maintenance calories change after losing weight?
Because you are now maintaining a smaller body: BMR scales with weight (10 kcal per kilo in the formula), and moving a lighter body costs less energy too. Recalculate every 5–10 lb of change — this "adaptive" drop is the main reason weight loss slows over time.