HisabCalc › Discounts & tips

Macro Calculator

Splits a daily calorie target into protein, carbohydrate, and fat grams from your chosen percentages.

Enter your numbers

Calories

Example: 2000

Protein (%)

Example: 30

Carbohydrate (%)

Example: 40

Fat (%)

Example: 30

Result

Currency

Figures are computed on your device; nothing is sent anywhere.

Formula

grams = calories * pct / 100 / (4 for protein and carbohydrate, 9 for fat); also returns the calorie share of each macro

How the calculation works

This split takes a total daily calorie target and divides it among protein, carbohydrate, and fat according to the percentage you assign to each macronutrient.

Protein and carbohydrate both provide about 4 kcal per gram while fat provides about 9 kcal per gram, so the grams differ even when two macros share the same percentage.

At 2000 kcal with 30 percent protein, 40 percent carbohydrate, and 30 percent fat you get 600, 800, and 600 calories, which become 150 g, 200 g, and about 66.7 g.

Common mistakes

The three percentages must add up to exactly 100; if they do not the tool throws an error rather than quietly normalising them for you.
Do not assume equal percentages mean equal grams: fat's 9 kcal per gram makes its gram figure roughly half of a same-percentage protein or carb share.
Enter the calorie figure as your daily total, not per meal, or every macro will come out about three times too small.

When to use it

Use it when planning a day of meals so you know how many grams of each macronutrient to aim for, not just the calorie total.
Use it to compare diet styles, such as a higher-protein cut versus a higher-carb endurance plan, by changing the percentages while keeping calories fixed.

Worked example

At 2000 calories with 30% protein, 40% carbohydrate and 30% fat you get 150 g protein, 200 g carbohydrate and about 66.7 g fat.

Protein (g) 150.00

Carbs (g) 200.00

Fat (g) 66.67

Protein calories 600.00

Carb calories 800.00

Fat calories 600.00

Common questions

Why do equal percentages give different gram amounts?

Protein and carbohydrate supply about 4 kcal per gram while fat supplies about 9 kcal per gram, so a 30% fat share weighs far fewer grams than a 30% protein share.

What happens if my percentages do not add up to 100?

The calculator refuses the input and reports an error, so you should adjust the three values until protein, carbohydrate and fat together total exactly 100%.

Last updated: 2026-10-03