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Simple Calculators

Macro Calculator

Calculate your daily protein, carbs, and fat targets based on your calories and diet style

Macro Calculator

Enter your daily calorie target (use a calorie calculator if unsure)

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Quick summary

This calculator divides your daily calories into protein, carbohydrates, and fat based on your chosen diet style. Four diet styles are supported: Standard (30/40/30), Low Carb (35/25/40), Ketogenic (25/5/70), and High Protein (40/35/25). Per-meal amounts are calculated assuming 3 meals per day.

Reviewed by Simple Calculators TeamLast reviewed

For information only — not medical advice. Results are estimates from published formulas and can't account for your health history. Talk to a doctor or other qualified clinician before making health decisions.

How to use this calculator

  1. Enter the inputs requested by the calculator.
  2. Choose the units or options that match your situation and review the assumptions.
  3. Run or update the calculation to see the result.
  4. Review the result, breakdown, and formulas shown on the page.
  5. Check the inputs, units, dates, and limitations before saving or sharing the result.

Macro Calculation Formulas

Protein Grams

Protein (g)=Calories×Protein %4\text{Protein (g)} = \frac{\text{Calories} \times \text{Protein \%}}{4}
Calories
Adjusted daily calorie target
Protein %
E.g. 0.30 for 30%
4
Protein has 4 kcal per gram

Worked example

2,000 cal standard diet (30% protein)

Given
Calories = 2,000
Protein % = 0.30
Calculation
Protein=2000×0.304\text{Protein} = \frac{2000 \times 0.30}{4}
Result
150g of protein per day

Fat Grams

Fat (g)=Calories×Fat %9\text{Fat (g)} = \frac{\text{Calories} \times \text{Fat \%}}{9}
Fat %
E.g. 0.30 for 30%
9
Fat has 9 kcal per gram

Worked example

2,000 cal standard diet (30% fat)

Given
Calories = 2,000
Fat % = 0.30
Calculation
Fat=2000×0.309\text{Fat} = \frac{2000 \times 0.30}{9}
Result
~67g of fat per day

Frequently asked questions

What is a macro?

Macronutrients — protein, carbohydrates, and fat — are the three main nutrients that provide calories. Protein and carbs each provide 4 kcal/g; fat provides 9 kcal/g.

What diet style should I choose?

Standard (30/40/30) suits most people. Low carb (35/25/40) reduces sugar and refined carbs. Ketogenic (25/5/70) puts your body into ketosis. High protein (40/35/25) supports muscle building.

How do I find my calorie target?

Use a calorie calculator (TDEE calculator) to estimate your maintenance calories, then enter that number here. The goal setting will add or subtract up to 300 kcal.

Key terms

Macronutrients
Protein, carbs, and fat — the three main sources of calories.
Ketogenic Diet
Very low-carb diet (under 5% of calories from carbs) designed to induce ketosis.
TDEE
Total Daily Energy Expenditure — the number of calories you burn each day.

Methodology, sources & limitations

This page shows the formula, assumptions, and limitations used for this estimate. Rates, thresholds, and other time-sensitive inputs can change, so verify them against the relevant official source before relying on a result.

For our review approach and the primary sources we consult, see the methodology and source policy. If you spot an outdated figure or formula, please contact us with a correction.