How to use it
Pick Male or Female, choose cm/kg or in/lb, then enter your age, height, weight and activity level. You instantly get your maintenance calories (your TDEE) plus a goal table with calorie targets for losing or gaining weight — no calculate button.
Tap Go advanced to add your body fat percentage. That switches the estimate to the Katch-McArdle equation, which uses your lean body mass, and reveals your BMR and a protein, carb and fat split for the day.
TDEE, BMR and maintenance calories
Your BMR is what you'd burn at complete rest. Multiply it by an activity factor and you get your TDEE — the calories you actually burn in a normal day. Eating at your TDEE holds your weight steady, which is why TDEE and maintenance calories are the same number.
Losing or gaining weight
To lose weight, eat below maintenance; to gain, eat above. A daily gap of about 500 calories is roughly half a kilo (about a pound) a week. The goal table does this for you. Treat every figure as a starting estimate and adjust from how your weight actually trends.
Get your body fat % first
For the more precise Katch-McArdle estimate, you need your body fat percentage — grab it in seconds with our Body Fat Calculator, then come back and enter it in advanced mode.
Activity multipliers
| Activity | × BMR |
|---|---|
| Sedentary — little/no exercise | 1.2 |
| Light — 1–3 days/week | 1.375 |
| Moderate — 3–5 days/week | 1.55 |
| Active — 6–7 days/week | 1.725 |
| Very active — hard training | 1.9 |
The equations we use
Mifflin-St Jeor (default) estimates BMR from sex, age, height and weight — the modern standard, accurate for most people. Katch-McArdle instead uses your lean body mass, so it can be sharper for lean or very muscular people. Advanced mode uses it automatically once you enter a body fat %.
A sensible macro split
Advanced mode splits your maintenance calories into protein (about 1.6 g per kg of bodyweight), fat (around 25% of calories) and carbs (the remainder). It's a balanced starting point — nudge it to fit your training and preferences.
Training too?
Set your fat-burning effort with the Heart Rate Zone Calculator, or plan runs with the Pace Calculator.
Common questions
What is TDEE and how is it calculated?
TDEE is your total daily energy expenditure — the calories you burn in a day. We estimate BMR with Mifflin-St Jeor from your sex, age, height and weight, then multiply by an activity factor from 1.2 (sedentary) to 1.9 (very active). That's your maintenance calories.
What are maintenance calories?
The daily intake that keeps your weight stable — it equals your TDEE. Eat below it to lose weight, above it to gain. A gap of about 500 calories a day is roughly half a kilo per week.
How many calories to lose or gain weight?
A common target is 250–500 calories below maintenance for steady fat loss, or 250–500 above for lean gaining. The goal table shows both. Adjust based on how your weight actually trends over a few weeks.
Mifflin-St Jeor or Katch-McArdle — which is more accurate?
Mifflin-St Jeor is the reliable default and needs no body composition. Katch-McArdle can be sharper for lean or muscular people because it uses lean body mass from your body fat %. Enter your body fat % in advanced mode to switch to it.
How much protein, carbs and fat should I eat?
A solid starting split is protein around 1.6 g per kg of bodyweight, fat around 25% of calories, and the rest from carbs. Advanced mode shows the breakdown in grams for your maintenance calories; scale it to your goal.