free tool · no signup · runs in your browser
Macro calculator
Daily calories plus protein, carb, and fat targets for losing, maintaining, or gaining — from the Mifflin-St Jeor equation, with the safety clamps shown instead of hidden. Every number checks out on a calculator.
For adults 18 and up — goal-based calorie planning (deficits and surpluses) is designed for adult bodies, and teens' needs are different. We don't plan weight-change targets for anyone under 18.
Goal
Safe planning band: 0.25–1% of bodyweight per week. Anything outside gets clamped — and we say so.
The raw math lands at 1,717 kcal — below the 1,800 kcal adult female safety floor — so your target holds at 1,800kcal. We don't plan under-eating weeks, so your real deficit is 264 kcal/day — not the 347 kcal that pace implies.
The math, step by step
1 · BMR (Mifflin-St Jeor): 10×63.05 + 6.25×165.1 − 5×34 − 161 = 1,331.4
2 · TDEE = 1,331.4 × 1.55 = 2,064 kcal
3 · Lose 0.5%/week = 63.05 kg × 0.5% = 0.32 kg/week × 7,700 kcal/kg ÷ 7 days = −347 kcal/day
4 · Safety floor: 2,064 − 347 = 1,717 is below the 1,800 kcal adult female floor → target held at 1,800 kcal
5 · Protein: 2.2 g/kg × 63.05 kg = 139 g (556 kcal) — the Cut preset — protects muscle in a deficit (Helms 2014 · Morton 2018)
6 · Remaining 1,800 − 556 = 1,244 kcal → 50% carbs = 156 g, the rest fat = 69 g (4 · 4 · 9 kcal per g)
✓ Check: 139×4 + 156×4 + 69×9 = 1,801 kcal — grams are rounded to whole numbers, so this can drift a few kcal from the target
Planning estimates, not clinical prescriptions — talk to a professional before dietary changes for a medical condition.
How this calculator works
- 1 · Your BMR comes from Mifflin-St Jeor (the resting-energy equation dietitians default to) and your TDEE from the standard activity multipliers — the same math as our TDEE calculator.
- 2 · Your goal sets the calorie adjustment: bodyweight × weekly rate × ~7,700 kcal/kg ÷ 7 days. The rate is clamped to the 0.25–1%/week safe band, and the target never goes below the 2,000/1,800 kcal adult floors — when either clamp fires, the calculator says so.
- 3 · Protein is set in g/kg bodyweight by goal (2.2 losing · 1.2 maintaining · 2.0 gaining), then the remaining calories split into carbs and fat at 4 · 4 · 9 kcal per gram.
Sources: Mifflin-St Jeor, Am J Clin Nutr 1990 · Academy of Nutrition and Dietetics systematic review, J Am Diet Assoc 2005 · Helms et al. 2014, JISSN · Morton et al. 2018, Br J Sports Med · Jäger et al. 2017, JISSN (ISSN position stand) · ~7,700 kcal/kg energy-balance approximation. Planning estimates, not clinical prescriptions.
Common questions
- How are the macros split?
- Protein is set first, in grams per kilogram of bodyweight, because it has a job — protecting muscle. The calories left after protein are split between carbs and fat by ratio, at 4 kcal per gram of protein and carbs and 9 per gram of fat. The calculation chain above shows the exact split used for your numbers.
- Why is protein higher when losing than when maintaining?
- In a calorie deficit, higher protein intake helps preserve lean mass. This calculator uses 2.2 g/kg for weight loss — consistent with the hypocaloric-athlete research (Helms 2014; Morton 2018) — 2.0 g/kg for gaining (the top of the ISSN 1.4–2.0 g/kg band), and a 1.2 g/kg planning baseline for maintenance.
- What are the safety clamps?
- Two, both shown when they fire rather than silently applied. The weekly rate is clamped to 0.25–1% of bodyweight per week — faster than 1% mostly costs muscle and adherence. And the calorie target never drops below 2,000 kcal for men or 1,800 kcal for women — we don't plan under-eating weeks.
- Where does the calorie adjustment come from?
- From the ~7,700 kcal per kilogram energy-balance approximation: your bodyweight × weekly rate gives kilograms per week, × 7,700 gives weekly calories, ÷ 7 gives the daily deficit or surplus. It is a planning heuristic, not a law of physics — real-world results drift, so adjust from what the scale does over a few weeks.
Just want maintenance? The free TDEE calculator shows your BMR and maintenance calories at every activity level.