Macro calculator

How does the macro calculator work?

Four steps, in this order:

1. Calories. The same daily target as our TDEE calculator: Mifflin-St Jeor resting energy, times a factor for your training days, adjusted for your goal, never under 1,200 calories (1,500 for men), rounded to the nearest 50.
2. Protein from your body weight and how you train, using the ranges in our protein guide. The split uses the middle of your range.
3. Fat at 30% of calories: calories × 0.30 ÷ 9.
4. Carbs for what’s left: (calories − protein × 4 − fat × 9) ÷ 4, and at least 50 g. Fiber at 14 g per 1,000 calories, and at least 25 g.

Steps 1, 3 and 4 are the Coachh app’s own math, line for line: the same code is tested against the app’s cases.

The protein ranges, per kilogram of body weight a day:

• Mostly inactive (the minimum): 0.8 g/kg (RDA, National Academies)
• Exercising regularly: 1.4–2 g/kg (ISSN position stand (Jäger et al., 2017))
• Lifting to build or keep muscle: 1.6–2.2 g/kg (Morton et al., 2018 meta-analysis)
• Over 65 (at least this much): 1–1.2 g/kg (PROT-AGE Study Group (Bauer et al., 2013))

What does a worked example look like?

A 40-year-old man, 5 ft 10 in and 200 lb (90.7 kg), training 2–3 days a week and exercising regularly, wants to lose weight:

1. Calories: maintenance about 2,644, minus 500, rounded to 2,150.
2. Protein: 1.4–2.0 g/kg × 90.7 kg is 125–180 g; the middle is 153 g (612 calories).
3. Fat: 2,150 × 0.30 ÷ 9 = 72 g (648 calories).
4. Carbs: (2,150 − 612 − 648) ÷ 4 = 223 g. Fiber: 2,150 ÷ 1,000 × 14 = 30 g.

That’s 28% of calories from protein, 30% from fat and 41% from carbs.

What do macros look like at common calorie targets?

With protein held at 140 g, the split at each target:

Why 30% fat and carbs for the rest?

Thirty percent sits in the middle of the 20–35% range the National Academies’ Dietary Reference Intakes give for adults, and the same report sets fiber at 14 g per 1,000 calories. Carbs get the remainder because, once protein and fat are covered, they’re the most flexible.

Protein comes first because it’s the macro with the clearest evidence for people who train: the ISSN position stand puts regular exercisers at 1.4 to 2.0 g/kg, and a 2018 meta-analysis found the muscle benefit of extra protein leveled off around 1.6 g/kg.

What are the limits of a macro calculator?

• Every number starts from an estimate of your calories, and Mifflin-St Jeor describes groups of people, not you. Your weight trend over a few weeks is the real test.
• On a low calorie target with high protein, carbs drop fast; at the 50 g minimum the calculator says so. That’s a sign the target may be too low for how you train.
• It doesn’t cover medical diets. Kidney disease, diabetes, pregnancy or a history of disordered eating need a doctor or a registered dietitian, not a calculator.
• Weight-loss diets in the 2013 AHA/ACC/TOS guideline start at 1,200 calories for women and 1,500 for men; this calculator never goes below those.

How is this different from the Coachh app?

The calories, fat, carbs and fiber are the same math. Protein is the one difference: the app starts from your goal weight, about 0.8 g per pound of goal weight as a 20 g range, or the range your coach set with you, while this page uses the protein guide’s ranges. So the app’s protein, and therefore its carbs, can differ by a few grams.

Coachh does this for you every day: it suggests these targets from your latest weigh-in, logs what you eat from a sentence, a photo or a barcode, and shows where you are against each macro. You can set your own targets instead. Photo estimates are the roughest of the three ways to log; how Coachh works says by how much.