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Macro Calculator

100% Free

Calculate your daily protein, carb, and fat targets from your body stats, activity level, goal, and diet style — with a clear macro split donut, instantly and in-browser.

Macro Split
Visual Donut
Instant
100% Client-Side

1. Your details

Gender
Diet approach

Informational only — not medical or dietary advice. Estimates use population-average equations; individual needs vary. Consult a professional before major diet changes.

2. Daily macro targets

2759kcal/day
Protein
207 g
30% · 828 kcal
Carbs
276 g
40% · 1104 kcal
Fat
92 g
30% · 828 kcal
BMR
1780 kcal
Maintenance (TDEE)
2759 kcal

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<iframe
  src="https://tools.town/embed/macro-calculator/"
  width="100%"
  height="600"
  style="border:none; border-radius:12px;"
  loading="lazy"
  title="Macro Calculator">
</iframe>

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How to Use

  1. 1 Pick your gender and enter age, height, and weight
  2. 2 Choose your activity level
  3. 3 Select a goal: lose, maintain, or gain weight
  4. 4 Pick a diet approach (balanced, low carb, high protein, or keto)
  5. 5 Read your daily calorie target and protein/carb/fat grams

Features

  • BMR via the Mifflin-St Jeor equation
  • TDEE from your activity level
  • Goal-adjusted calorie target (deficit, maintenance, or surplus)
  • Four diet presets with sensible macro ratios
  • Visual donut showing the protein/carb/fat split
  • Save profiles, per-meal splits, and exports with Pro

Why it Matters

Hitting a calorie target is only half the picture — how those calories split across protein, carbs, and fat shapes how you feel, perform, and change body composition. Translating a goal into concrete daily grams turns vague intentions into a plan you can actually shop and cook for.

★★★★★

Use Cases

Body Recomposition

Set protein high enough to preserve muscle in a deficit

Meal Planning

Turn a calorie goal into shoppable gram targets

Gym Goals

Dial in a surplus and protein for lean gains

Diet Switching

Compare balanced, low-carb, and keto splits instantly

What this tool does

The Macro Calculator converts your body stats and goal into a daily calorie target and a concrete split of protein, carbs, and fat in grams. Pick a diet style — balanced, low carb, high protein, or keto — and see the split as a donut plus a per-macro calorie breakdown.

How it works

It estimates BMR with the Mifflin-St Jeor equation, multiplies by your activity level for TDEE, adjusts for your goal, then divides the calorie target by your diet’s macro ratio. Grams come from the Atwater factors: 4 kcal/g for protein and carbs, 9 kcal/g for fat.

A note on accuracy

This is an informational estimate, not medical or dietary advice. The formulas are population averages; individual needs vary with genetics, health, and training. Treat the targets as a starting point and consult a doctor or registered dietitian before significant changes, especially aggressive deficits.

Free vs Pro

The free calculator runs one scenario and stores nothing. A proposed Macro Pro would add saved profiles, per-meal breakdowns, custom gram targets, and exports — while the single-shot calculator stays free.

Privacy

Everything runs locally in your browser. Nothing you enter is uploaded, logged, or stored.

Frequently Asked Questions

How does the macro calculator work?
It estimates your BMR with the Mifflin-St Jeor equation, multiplies by an activity factor to get your TDEE, adjusts for your goal (a deficit to lose, surplus to gain), then splits the calorie target into protein, carbs, and fat using your chosen diet ratio. Grams are derived using 4 kcal per gram of protein and carbs and 9 kcal per gram of fat.
What are macros?
Macros — short for macronutrients — are protein, carbohydrates, and fat, the three nutrients that supply calories. Protein supports muscle, carbs fuel activity, and fat supports hormones and absorption. Hitting your macro targets, not just a calorie number, is what shapes body composition and energy.
Which diet split should I pick?
Balanced (30/40/30) suits most people. High protein helps when preserving muscle in a deficit, low carb suits those who feel better on fewer carbs, and keto pushes fat very high and carbs very low. There's no single best split — pick what you can stick to.
Are these targets exact?
No. They're estimates from population-average formulas. Real needs vary with genetics, health, sleep, and training. Use the numbers as a starting point, track how you respond over 2–3 weeks, and adjust — or consult a registered dietitian.
Can I save my profile or get a per-meal breakdown?
The free tool runs one calculation and stores nothing. Macro Pro will add saved profiles, per-meal macro splits, custom gram targets, and PDF/CSV export — while the core calculator stays free.
Is my data stored anywhere?
No. Every calculation runs locally in your browser. Nothing you enter is uploaded, logged, or stored.
📖

Want to understand the math?

Browse all guides →
How to Calculate Your Macros
macros

How to Calculate Your Macros: A Practical Guide

Learn what macros are, how a macro calculator turns your stats into protein, carb, and fat targets, which diet split to choose, and how to adjust as you go.

24 Jun 2026

5 min read

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