TDEE Calculator

How your daily calories are estimated

Your Total Daily Energy Expenditure (TDEE) is the number of calories your body uses in a day. It's built in two steps. First we estimate yourBasal Metabolic Rate (BMR) — the energy your body needs at complete rest just to keep functioning. Then we multiply that BMR by an activity multiplier that accounts for movement and exercise, giving your maintenance calories.

The Mifflin-St Jeor equation

By default this calculator uses the Mifflin-St Jeor equation, which research has found to be among the most accurate predictive BMR formulas for the general adult population. It is:

• Men: BMR = 10 × weight(kg) + 6.25 × height(cm) − 5 × age + 5
• Women: BMR = 10 × weight(kg) + 6.25 × height(cm) − 5 × age − 161

Source: Mifflin MD, St Jeor ST, Hill LA, Scott BJ, Daugherty SA, Koh YO. "A new predictive equation for resting energy expenditure in healthy individuals." American Journal of Clinical Nutrition, 1990;51(2):241–247.

You can also switch to the revised Harris-Benedict equation (Roza & Shizgal, 1984) or the Katch-McArdle formula. Katch-McArdle is based on lean body mass rather than total weight, so it can be more accurate for very lean or very muscular people — but it requires you to enter an estimated body-fat percentage.

Activity multipliers

BMR is scaled to TDEE using the activity factors from the Harris-Benedict tradition. Pick the level that best matches a typical week — most people overestimate, so when in doubt, choose the lower option:

• Sedentary (× 1.2) — little or no exercise, desk job.
• Lightly active (× 1.375) — light exercise 1–3 days/week.
• Moderately active (× 1.55) — moderate exercise 3–5 days/week.
• Active (× 1.725) — hard exercise 6–7 days/week.
• Very active (× 1.9) — hard daily training or a physical job.

Cut, maintain and bulk targets

From your maintenance calories the tool shows three scenarios. The cut applies a 20% deficit, the maintain figure is your TDEE itself, and thebulk applies a 10% surplus — moderate, generally sustainable rates. The approximate weekly weight change shown for each card assumes roughly 7,700 kcal per kilogram of body mass; real results vary with water balance, training and adherence.

All figures are estimates. Because every equation is a population average, treat the number as a starting point: track your weight trend for two to three weeks and adjust your intake up or down based on what actually happens on the scale.

Frequently asked questions

Which BMR formula should I use?

Mifflin-St Jeor is the recommended default for most people and is what the tool uses unless you change it. If you know your body-fat percentage and are unusually lean or muscular, Katch-McArdle may track your needs more closely because it works from lean mass. Harris-Benedict is included for comparison; in practice the three usually land within a few percent of each other.

Why is my real-world result different from the estimate?

These equations predict an average — individual metabolism varies, and the activity multiplier is a broad bracket rather than a precise measurement. Day-to-day weight also swings with water, sodium and glycogen. Use the estimate to set a starting intake, then let your weight trend over a couple of weeks tell you whether to nudge the number.

How fast should I lose or gain weight?

A roughly 20% deficit (about 0.5 kg / 1 lb per week for many people) and a modest 10% surplus are commonly used because they're easier to sustain and tend to preserve muscle and performance better than aggressive swings. Larger deficits aren't necessarily "better" — adherence over time matters far more than speed.

Is my information saved or sent anywhere?

No. Your inputs are stored only in this browser so the calculator remembers them on your next visit. Nothing is uploaded to a server and no account is required — clearing your browser data removes them.