Macro Split Calculator
Turn a daily calorie target into protein, carb and fat grams using balanced, high-protein, low-carb, keto or custom splits.
About this tool
Macro Split Calculator
Turn a daily calorie target into protein, carb and fat grams using balanced, high-protein, low-carb, keto or custom splits.
Macro Split Calculator converts a daily calorie target into grams of protein, carbohydrate and fat using the standard Atwater values — 4 kcal per gram for protein and carbs, 9 kcal per gram for fat. Choose a preset such as balanced 30/40/30, high protein 40/35/25, low carb, ketogenic 25/5/70 or high-carb endurance, or type your own percentages and the tool checks they add to 100. It also divides each macro across your chosen number of meals so you know what a single plate should look like.
How to use Macro Split Calculator
- 1
Open Macro Split Calculator on AltFTool — it loads instantly in your browser.
- 2
Enter 'Daily calories (kcal)' (800-8,000) and 'Meals per day' (1-10), then pick a 'Diet split' preset — from Balanced (30P / 40C / 30F) to Ketogenic (25P / 5C / 70F) — or Custom split.
- 3
For a custom plan, press 'Fine-tune these percentages' and set Protein %, Carb % and Fat %; the tool flags any split that does not total 100%.
- 4
Read the 'Protein target' g/day headline, the grams-and-kcal table for all three macros and the per-meal cards, then press 'Copy result'.
Why use Macro Split Calculator
Six ready-made splits
Balanced, high protein, low carb, ketogenic and endurance presets, plus a fully custom option.
Custom split validation
Percentages that don't total 100 are flagged immediately instead of silently producing wrong grams.
Per-meal breakdown
Divides protein, carbs and fat across 1 to 10 meals so each plate has a concrete target.
Common use cases
- Translate the calorie number from a TDEE calculation into macros you can actually log in a food-tracking app.
- Compare what switching from a balanced split to keto does to your daily carb allowance in grams.
- Work out per-meal protein when you're meal-prepping four containers for the week.
Frequently asked questions
How are macro grams calculated from calories?
Each macro's calorie share is the target multiplied by its percentage, then divided by its energy density: 4 kcal per gram for protein and carbohydrate, 9 kcal per gram for fat.
What is a good macro split for fat loss?
There is no single best split — total calories drive weight change. Higher protein splits (around 30-40% of calories) are commonly used during a deficit because protein helps preserve lean mass and increases fullness.
Why do my rounded grams not add back to my exact calories?
Grams are rounded to whole numbers for practicality, so the recomposed total can be off by a few kcal. Use the unrounded percentages if you need an exact match.
Do I need to hit my macros exactly every day?
Most people do fine landing within about 5-10 grams of each target and looking at weekly averages. This tool is informational — speak to a dietitian or doctor before following a restrictive diet such as ketogenic eating.
Embed this tool on your site
Add the Macro Split Calculator widget to your blog or website — free, responsive, no signup. Just keep the “Widget by AltFTool” credit link visible.
<iframe src="https://www.altftool.com/embed/widget/macro-split-calculator"
title="Macro Split Calculator — free AltFTool widget"
width="100%" height="640" style="border:0;border-radius:12px;overflow:hidden"
loading="lazy" referrerpolicy="no-referrer-when-downgrade" allow="clipboard-write"></iframe>
<p style="font-size:12px;margin:4px 0 0">Widget by <a href="https://www.altftool.com/tools/all/macro-split-calculator?utm_source=embed&utm_medium=widget" rel="nofollow">AltFTool — free online tools</a></p>