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Macro Split Calculator

A macro split turns a daily calorie budget into gram targets for protein, carbohydrate, and fat using the standard energy densities: 4 kcal per gram of protein or carbohydrate and 9 kcal per gram of fat. Pick a plan — balanced (30/40/30), low-carb (30/20/50), or high-protein (40/35/25) — and the calculator does the division.

Protein · Carbs · Fat
180g · 240g · 80g
2,400 kcal / day · Balanced
Daily macros
Balanced
2,400KCAL / DAY
Protein30%180g
Carbs40%240g
Fat30%80g
Inputs
calories a day, split
Part of a chain:BMRTDEECalorie deficitMacro split — you are here
Protein is the anchor macro
It matters most for satiety and holding muscle in a deficit — roughly 0.7–1 g per pound is a common target. Fat has a floor near 0.3 g/lb for hormones; carbs are the flexible lever.
These splits are starting points
Balanced spreads calories evenly and suits general maintenance. The AMDR permits wide macro ranges, so adjust to how you eat and train — hitting your calorie total matters more than the exact ratio.
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Uses your inputs above
180g · 240g · 80g protein · carbs · fat. Want to try a variation?

The math

Reviewed 2026
Formula
g = kcal · ratio / (4 for P/C, 9 for F)
Sources: AMDR (IOM)

Related calculators

TDEE
Calorie deficit
BMR

Example: how macro split is calculated

Step-by-step with default inputs

Suppose you put the default values into Macro Split Calculator:

Daily calories
2400
Plan
Balanced

Plug those into the formula g = kcal · ratio / (4 for P/C, 9 for F) and the result is:

Protein · Carbs · Fat
180g · 240g · 80g

How to calculate macro split by hand

  1. Start with your daily calorie budget (kcal) — the TDEE calculator gives a maintenance estimate.
  2. Multiply kcal by the plan's protein ratio and divide by 4 for grams of protein.
  3. Multiply kcal by the carb ratio and divide by 4 for grams of carbohydrate.
  4. Multiply kcal by the fat ratio and divide by 9 for grams of fat.

How does the macro split calculator work?

Each macronutrient's share of calories is fixed by the chosen plan — balanced allocates 30% protein, 40% carbs, 30% fat; low-carb 30/20/50; high-protein 40/35/25 — then converted to grams with the standard energy factors of 4 kcal per gram for protein and carbohydrate and 9 kcal per gram for fat, the values used throughout the Institute of Medicine's Dietary Reference Intakes. The presets are common templates rather than clinical prescriptions, and the calculator works purely from calories: it does not scale protein to body weight or lean mass, which serious training plans often do.

References: AMDR (IOM).

Last reviewed July 2, 2026 · Editorial policy

Frequently asked questions

Why divide fat by 9 but protein and carbs by 4?

Fat is more energy-dense — about 9 kcal per gram versus 4 kcal per gram for protein and carbohydrate. These are the standard energy factors used in the IOM's dietary reference intakes, and they are why fat grams always look small next to their calorie share.

How many grams of protein does each plan give?

At the default 2,400 kcal: the balanced and low-carb plans (30% protein) both give 180 g, while high-protein (40%) gives 240 g. Only the ratios differ between plans — every plan spends exactly the calorie budget you enter.

Do the plans change my total calories?

No — the split reallocates the same budget. At 2,400 kcal, switching balanced to low-carb moves carbs from 240 g down to 120 g while fat rises from 80 g to about 133 g, and the calorie total stays identical.

How accurate is this macro split calculator?

The math is deterministic — the same inputs always produce the same output, and the formula is shown above. Accuracy of the answer for your situation depends on how well your inputs match reality and how well the formula models the question.

Is this a substitute for medical advice?

No. Health calculators give informational baselines from published formulas. For decisions about your body, talk to a clinician.

How do I share my result?

Hit Share at the top of the page. Every input you change is encoded in the URL, so a permalink reproduces exactly what you see. No account needed.