TDEE Calculator

How to use this calculator

1. Choose Imperial (lbs / ft) or Metric (kg / cm).
2. Select your biological sex.
3. Enter your age, height, and weight.
4. Select your activity level — be honest about your average week, not your best week.
5. Click Calculate TDEE.

Tip: TDEE is your maintenance calories — the amount you need to eat to stay the same weight. Eat less to lose weight; eat more to gain. The "steps to add 500 kcal deficit" result shows how much extra walking creates a 1 lb/week weight loss rate through movement alone.

How it works

The Mifflin-St Jeor formula

BMR (Basal Metabolic Rate) is the calories your body needs at complete rest — just to keep organs functioning. This calculator uses the Mifflin-St Jeor equation, validated in a 2005 systematic review in the Journal of the American Dietetic Association as the most accurate predictive equation for most adults: Men: BMR = (10 × kg) + (6.25 × cm) − (5 × age) + 5 and Women: BMR = (10 × kg) + (6.25 × cm) − (5 × age) − 161. TDEE is then calculated as TDEE = BMR × activity multiplier, using Harris-Benedict activity factors (1.2–1.9) that account for exercise frequency and intensity.

TDEE and weight management

A deficit of 3,500 calories produces approximately 1 pound of fat loss — the basis of the "500 kcal/day deficit = 1 lb/week" guideline widely used in clinical nutrition. This deficit can come from eating less, moving more, or both. Walking contributes roughly 0.04 kcal per step at average weight, meaning approximately 12,500 steps above your baseline creates a 500 kcal deficit. In practice, the most sustainable approach combines a modest dietary reduction (300–400 kcal) with increased walking (100–200 extra kcal), rather than targeting either extreme alone.

Track it with StepGoals

Walking is the most accessible lever most people have for increasing their daily calorie burn. StepGoals tracks your step count and displays active calorie burn directly from Apple Health on the main screen — including from Apple Watch heart rate data when available, which makes the calorie figure more accurate than step-count estimates alone. You can set a calorie goal alongside your step goal under Settings → Goals.

Once you know your TDEE from this calculator, you can use the Walking Weight Loss Planner to model how long it takes to reach a specific weight goal through walking, or the Steps to Calories calculator to see exactly how many calories a given step count burns at your weight.