MacroDiet's free calculators — a macro calculator, a calorie calculator and a calorie-deficit calculator on macrodiet.fit, with the same three and six training tools on zyra.fit — compute a resting rate, a total daily energy expenditure, a daily target and a protein / fat / carb split from seven inputs, using the v2 algorithm the app itself runs. What they cannot compute is you: they are population estimates with fixed assumptions, and this guide is exact about both. MacroDiet is live at macrodiet.fit and evolving; screens change as features ship, and anything marked "coming" below is not in the app yet.
What it does
Each macrodiet.fit calculator page is the same layout: a heading and intro, the calculator card, a How We Calculate block, seven FAQs, related calculators, a disclaimer and a last-updated line. The pages exist at the root and under /de, /es, /fr, /it and /nl — six languages, same formula, same numbers. The zyra.fit versions (macro, calorie, calorie deficit) are rebuilt on the same code and declare the macrodiet.fit pages as their canonical home; the other six on the calculators hub are zyra.fit's own.
The inputs are: unit system (metric or imperial), sex, age, height, weight, an activity level from a five-item list, and a goal (lose, maintain, gain). The outputs are BMR, TDEE, a recommended daily calorie figure and, on the macro and deficit pages, protein, fat and carb grams.
Step by step
- Pick units — kg/cm or lb/ft-in. Conversions happen in the page.
- Enter sex, age, height and weight. These four are the whole resting-rate equation.
- Choose an activity level. The list is Sedentary (little or no exercise), Lightly active (1–3 days a week), Moderately active (3–5), Very active (6–7), Extra active (twice a day or a physical job). Behind the scenes each maps onto the app's two questions — sessions per week and movement outside training — as the table below shows.
- Choose a goal. Maintain returns the TDEE; lose and gain apply the rate-based change.
- Read the results and, on macrodiet.fit, optionally follow "Get started free" into the app to save them. Nothing is stored otherwise.
What the numbers mean
The formula. BMR = 10 × kg + 6.25 × cm − 5 × age + 5 (men) or − 161 (women). TDEE = round(BMR × multiplier). For lose or gain, change = weight × 0.005 × 7,700 / 7 a day, capped at 35% of TDEE; for lose, the result is raised to the calorie floor (1,500 men / 1,200 women) if it falls below. Protein is 1.6 g/kg (+0.2 when losing), fat is 35% of the calories left after protein (never below the larger of 0.6 g/kg and 20% of calories), carbs are the rest. Every step is in how to calculate TDEE and the app-side detail in what onboarding asks.
The activity mapping, which is where most "why is this different from calculator X" questions live (why calculators disagree):
| Calculator activity level | Sessions per week it assumes | Movement outside training | Multiplier |
|---|---|---|---|
| Sedentary | 0 | sedentary | 1.2 − 0.05 = 1.15 |
| Lightly active | 1–3 | sedentary | 1.375 − 0.05 = 1.325 |
| Moderately active | 4–6 | moderate | 1.55 |
| Very active | 7+ | very active | 1.725 + 0.10 = 1.825 |
| Extra active | 7+ | very active | 1.825 (same as Very active) |
The fixed assumptions. To fit on one card the calculators pin the settings the app asks about:
| The app asks | The calculator assumes | Effect on the number |
|---|---|---|
| Rate: 0.3 / 0.5 / 0.75% a week | moderate, 0.5% | for 85 kg, 468 kcal a day off maintenance rather than 281 or 701 |
| Diet style: balanced / low-fat / low-carb / keto | balanced | fat 35% of the remainder; keto would fix carbs at 30 g |
| Protein: low → extra high | moderate, 1.6 g/kg | 136 g for 85 kg, 153 g when losing |
| Calorie floor: standard / lower | standard | 1,500 / 1,200 kcal floor for lose |
| Weight trend, body-fat range, weight history, experience, identity | stable · 18–23% (men) / 24–29% (women) · no · beginner · regular | none today — the v2 maths does not read them |
Worked, 85 kg / 180 cm / 30 / male / moderately active / lose: BMR 1,830 · TDEE 2,837 · target 2,369 · 153 P · 68 F · 286 C. The zyra.fit page defaults to this example so the first render matches.
What a calculator does not compute. Whether the estimate is right for you. The resting-rate equation explains roughly seven-tenths of the variation between people; the rest is individual, and the activity list rounds a whole week into one of five buckets. A typical miss is 100–200 kcal; 400–500 is not rare. The app exists for the part the calculator cannot do — comparing the number with logged intake and weight change over weeks (macro calculator versus tracking app).
In plain terms: the calculators give the app's starting numbers under its default settings, instantly and privately. They are a first guess to test, not a result.
Gotchas
- Very active and Extra active give the same multiplier. Both map to 7+ sessions and very active movement; the second label is for people who recognise themselves in it, not a higher number.
- Age is an integer, not a birth date. The app uses your date of birth; the calculator builds one from the age, so results can differ by a year's worth of the age term (5 kcal) around a birthday.
- The calculators cannot show the keto, low-carb, aggressive-rate or lower-floor variants. Those are app settings; the protein calculator does let you change the protein tier on its own.
- A result at exactly 1,500 or 1,200 kcal means the floor fired. The zyra.fit versions show the engine's own warning when that happens; read why calculators stop at 1,200.
- The disclaimer is part of the tool. macrodiet.fit's pages end with a note that the results are estimates for information only, not medical or dietary advice — the same footing as this site.
The short version
Three free nutrition calculators on macrodiet.fit (six languages) and nine on zyra.fit compute BMR, TDEE, a target and a macro split from sex, age, height, weight, a five-level activity and a goal, with the v2 algorithm and fixed defaults — moderate rate, balanced split, moderate protein, standard floor. They run in the browser, store nothing, and estimate to within a couple of hundred kcal for most people. The number is where nutrition tracking starts, not where it ends. Educational overview only — not medical advice.