Split energy into protein, carbs, and fat

You enter a calorie budget — often from the calorie calculator — and one of three profiles. Each profile is a triplet of percents that sum to 100%. Grams follow: protein = (kcal × share) / 4, carbohydrate = (kcal × share) / 4, fat = (kcal × share) / 9. The 4 / 4 / 9 factors are the usual Atwater energy equivalents used on labels, not a lab analysis of a mixed meal. USDA Dietary Guidelines speak to overall eating patterns (food groups, added sugars, sodium). They do not dictate these three percents: we say so to avoid treating “25 / 45 / 30” as a federal nutrition decree.

protéines (g) = calories × part_protéines / 4

glucides (g) = calories × part_glucides / 4

lipides (g) = calories × part_lipides / 9

The three templates are interface choices: balanced 25/45/30, higher protein 30/40/30, lower carb 30/30/40. They do not copy a prescription, a named sports protocol, or a USDA macro table. Alcohol (7 kcal/g) is not a fourth slider. A real food mixes all three macros; this page is only arithmetic on a total. For a g/kg protein target rather than a percent of calories, the protein calculator is more direct, with EFSA / ISSN coefficients spelled out there.

Starting calories

If you came from the calories page, copy the displayed goal, not BMR. A total that is too low stays too low once split.

Split template

Changing template moves grams without changing total energy. “Lower carb” here is 30% of energy from carbohydrate, not a ketogenic diet.

Assumptions

• The calorie total was already chosen elsewhere (TDEE, goal, or a trial).
• 4 / 4 / 9 apply to the macros as energy, not to a mixed dish analyzed in a lab.
• Percents are HexaCalc templates, not individual DRIs.

Limits

• No fiber, alcohol, micronutrients, or fat quality.
• No automatic link to body weight (see protein in g/kg).
• USDA Dietary Guidelines are not translated into these three sliders.
• Unsuitable for insulin-treated diabetes, kidney disease, medical diets — outside this tool.

Grams help sketch a typical day, for example against food pages. They do not say breakfast “must” be high protein. If protein as a percent is far from a g/kg target you use elsewhere, that is consistent: two logics (energy share vs per kilogram). The protein calculator clarifies the second.

• Taking “balanced” as a USDA badge.

  It is a 25/45/30 triplet chosen for the tool. Dietary Guidelines talk mainly about foods and patterns, not this split.

• Forgetting that 30% of energy from fat is not 30% of plate weight.

  Fat is denser in kcal per gram. 70 g of fat is not 70 g of “visible grease” only.

• Adding shake macros “on top” of a total already typed.

  If 2,100 kcal already includes everything, so do the grams. Otherwise raise the calorie budget first.

• Calorie calculatorThree steps: Mifflin-St Jeor resting burn, times a lump activity factor, then a goal offset. The result is an estimate, not a diet.
• Protein calculatorThree coefficients per kilogram: the EFSA PRI 0.83 g/kg for a healthy adult, 1.2 g/kg as an internal “active” rung, 1.6 g/kg as an example in the middle of the 1.4–2.0 g/kg range often cited for training (ISSN 2017).
• Basal metabolic rateTwo resting-energy equations: Mifflin-St Jeor as the main result, revised Harris-Benedict (1984) as a comparison. No activity factor is applied.
• TDEE calculatorTDEE here is Mifflin-St Jeor resting metabolism times an activity factor. It includes no deficit, no surplus, and no 1,200 kcal floor.

Written by Rédaction HexaCalc (editorial team). Content last updated: August 25, 2026. No third-party medical or financial review is claimed.

• Repères nutritionnels du PNNS — Santé publique France / ANSES