Calculate your TDEE and BMR with the Mifflin–St Jeor formula. Free, no signup — get maintenance, weight-loss, and weight-gain calorie targets.
Between 14 and 100.
Most people overestimate this. When unsure, pick the lower option.
Estimates use the Mifflin–St Jeor equation with an activity factor of ×1.55. Expect roughly ±10% accuracy — adjust based on what the scale does over 2–3 weeks.
Your Total Daily Energy Expenditure is the total number of calories you burn in a day — at rest plus everything you do on top of that. It is the single most useful number for any nutrition goal, because every diet decision comes down to comparing what you eat against what you burn. Eat at your TDEE and your weight holds steady; eat below it and you lose; eat above it and you gain. The whole calculator exists to give you that one anchor number.
We estimate your resting burn (BMR) with the Mifflin–St Jeor equation, which a systematic review by the Academy of Nutrition and Dietetics found to be the most reliable predictive equation for healthy adults. For men it is 10 × kg + 6.25 × cm − 5 × age + 5; for women the constant at the end is − 161. That BMR is then multiplied by an activity factor — 1.2 for sedentary up through 1.9 for very active — to arrive at your TDEE. The biggest source of error is almost always the activity factor, so be honest, and if you sit between two levels, choose the lower one.
Knowing your TDEE is the easy part. Hitting a calorie target most days of the week for months is what actually changes your body — and that is a consistency problem, not a math problem. This is where a habit tracker earns its keep: log "stayed in my calorie range" or "logged my food" as a simple daily check-in in HabitBox, and the streak gives you a visible reason to keep the chain going. HabitBox is free, works on iOS and Android, keeps your data on your device with no account, and a check-in is a single tap.
Note: these are population estimates for healthy adults and are not medical advice. If you are pregnant, have a metabolic or thyroid condition, or are planning a large calorie change, talk to a doctor or registered dietitian first.
BMR (Basal Metabolic Rate) is the energy your body burns at complete rest just to keep you alive — breathing, circulation, cell repair. TDEE (Total Daily Energy Expenditure) is your BMR multiplied by an activity factor to account for movement, exercise, and digestion. TDEE is the number that matters for diet planning: eat at your TDEE to maintain weight, below it to lose, and above it to gain.
It uses the Mifflin–St Jeor equation, published in 1990, which research consistently finds to be the most accurate predictive BMR formula for the general population. For men: BMR = 10 × weight(kg) + 6.25 × height(cm) − 5 × age + 5. For women: the same, but − 161 instead of + 5. TDEE is then BMR × your activity factor (1.2 sedentary up to 1.9 very active).
Predictive equations are estimates with a typical error of around ±10%, because they can't see your actual muscle mass, genetics, or true activity level. Treat the number as a starting point. Track your weight and food intake for 2–3 weeks: if your weight is stable, that intake is your real maintenance. Adjust your target up or down by 100–200 calories from there based on what the scale actually does.
Most people overestimate this. 'Sedentary' (1.2) fits a desk job with little deliberate exercise. 'Lightly active' (1.375) is light workouts 1–3 days a week. 'Moderately active' (1.55) is genuine exercise 3–5 days a week. Reserve 'Active' (1.725) and 'Very active' (1.9) for hard daily training or a physically demanding job. When in doubt, pick the lower option — it's easier to add food than to wonder why the scale isn't moving.
A deficit of about 500 calories per day predicts roughly 0.45 kg (1 lb) of fat loss per week, since a pound of fat stores about 3,500 calories. A 250-calorie deficit gives a gentler ~0.23 kg (0.5 lb) per week, which preserves more muscle and is easier to sustain. Going much steeper than 500–750 calories below TDEE tends to increase muscle loss, hunger, and the odds you quit — slower is usually smarter.
Knowing your number is step one. Hitting it most days is what changes your body. HabitBox lets you track 'stayed in my calorie range' as a one-tap daily habit and watch the streak compound.
Free · Local-only data · No account required