Calculators / Calorie calculator
Calorie calculator
A calorie calculator estimates how much energy a body uses in a day. This one shows the three numbers behind that estimate — BMR from Mifflin-St Jeor, the activity multiplier, and their product, TDEE — and what MacroDiet's lose and gain settings do to it.
Also on macrodiet.fit in six languages — same formula, same numbers.
BMR = 10×85 + 6.25×180 − 5×30 + 5 = 1830
TDEE = round(1830 × 1.55) = 2,837
| Goal (moderate rate, 0.5% BW/week) | kcal/day | vs TDEE |
|---|---|---|
| Lose | 2,370 | −467 |
| Maintain | 2,837 | — |
| Gain | 3,305 | +468 |
How the math works
- BMR = 10 × kg + 6.25 × cm − 5 × age + 5 (men) or − 161 (women) — Mifflin-St Jeor. Example: 850 + 1,125 − 150 + 5 = 1,830.
- TDEE = round(BMR × multiplier), the multiplier being training days per week plus a daily-movement adjustment. Example: 1,830 × 1.55 = 2,837.
- Lose / gain: kg × rate% × 7,700 ÷ 7 per day, capped at 35% of TDEE; cuts are held at a calorie floor. Example: 85 × 0.5% × 7,700 ÷ 7 = 467 → 2,370 / 3,305 kcal.
Activity levels and their multipliers
| Level | Training days / week | Daily movement | Multiplier | TDEE for the example |
|---|---|---|---|---|
| Sedentary (little or no exercise) | 0 | sedentary | × 1.15 | 2,105 |
| Lightly active (1–3 days/week) | 1-3 | sedentary | × 1.325 | 2,425 |
| Moderately active (3–5 days/week) | 4-6 | moderate | × 1.55 | 2,837 |
| Very active (6–7 days/week) | 7+ | very active | × 1.825 | 3,340 |
| Extra active (2× per day or physical job) | 7+ | very active | × 1.825 | 3,340 |
Multipliers are the v2 constants: training days {0: 1.2, 1–3: 1.375, 4–6: 1.55, 7+: 1.725} plus daily movement {sedentary −0.05, moderate 0, very active +0.1}. The two top levels share one multiplier in the source algorithm.
What the numbers are not
A BMR equation predicts the average of many people, not the metabolism of one — individual results can be a few hundred kcal above or below it. The multiplier is the coarsest input of all. Use the result as a first estimate, then let the weight trend correct it; that is the loop MacroDiet is built around. This is arithmetic, not medical advice.
Frequently asked
What is TDEE?
Total daily energy expenditure — an estimate of all the calories a body uses in a day: the resting share (BMR), digestion, and everything from walking to training. The calculator gets it as BMR × an activity multiplier; for the 85 kg example that is 1,830 × 1.55 = 2,837 kcal.
How many calories should I eat per day?
The calculator does not tell anyone what to eat; it estimates maintenance (TDEE) from sex, age, height, weight and activity, and then shows what its lose and gain settings do to that number — for the example, 2,370 kcal on a moderate cut and 3,305 kcal on a moderate gain. The estimate is a population average; MacroDiet checks it against the weight trend and adjusts.
Which activity level should I choose?
Pick the row that describes an actual week, not an intended one. Each level maps onto two things the formula reads — training days per week and how much you move outside training — and the multipliers run from × 1.15 (sedentary) to × 1.825 (very or extra active). The table under the calculator lists the mapping; the difference between neighbouring rows is a few hundred kcal, which is also roughly the equation's own margin of error.
What is the difference between BMR and TDEE?
BMR (basal metabolic rate) is the energy used at complete rest — 1,830 kcal for the example, from the Mifflin-St Jeor equation. TDEE adds activity and digestion on top by multiplying BMR: × 1.55 here, giving 2,837 kcal. BMR is a component; TDEE is the whole day.
Why does my number differ from other calculators?
Three reasons: a different BMR equation (Harris-Benedict, Katch-McArdle and Mifflin-St Jeor each give different values for the same person), different activity multipliers (there is no single standard set), and rounding at different steps. This calculator uses Mifflin-St Jeor and the multipliers in the table below, and rounds once, at TDEE — so the same inputs always reproduce the same number here and on macrodiet.fit.
How many calories do I need to lose weight?
The calculator's lose setting subtracts a rate-based amount from TDEE: body weight × 0.3%, 0.5% or 0.75% per week, converted at 7,700 kcal per kg and divided by 7 — 467 kcal/day for 85 kg at the moderate rate, so 2,370 kcal. The change is capped at 35% of TDEE and the target is held at a calorie floor. The calorie deficit calculator shows the cap and floor at work.
Do I need to count calories every day?
The estimate itself takes ten seconds and is a starting point, not a measurement. What makes it useful is comparison over time: MacroDiet logs intake against the target and reads the weight trend over weeks. As body weight changes the inputs change too — at 80 kg instead of 85 the same person's TDEE is 2,759 kcal — so recomputing after a change in weight or routine matters more than logging perfectly every single day.
Related calculators
Track against these targets
MacroDiet's own calculators run this exact v2 formula, and the same zyra-algo engine sets the targets inside the app — where logged food is compared against them and the dashboard shows the weight trend. Web app, live at macrodiet.fit — nothing to install.
Zyra is a training and nutrition tracking tool. Nothing on this page is medical advice, a diagnosis, or an individual prescription. The numbers are estimates from published formulas and the apps' own rules — consult a qualified professional for decisions about your health, and a coach for your training.