Macro Split Calculator
Carbs and protein give 4 kcal per gram, fat gives 9. Choose the percentages and this converts them to grams.
Your numbers
Carbs
225g
Protein
150g
Fat
56g
Formula
Carbs = Calories × A share ÷ 100 ÷ 4, Fat = Calories × (100 − A share − B share) ÷ 100 ÷ 9
Most guidance keeps fat at 20% or more — it is needed for hormone synthesis and fat-soluble vitamin absorption.
What to enter
| Input | Default | Accepted range |
|---|---|---|
| Calories (kcal)Energy, in kilocalories. | 2,000 | 500 ~ 6,000 |
| A share (%)The percentage that applies to the first item. | 45 | 0 ~ 100 |
| B share (%)The percentage that applies to the second item. | 30 | 0 ~ 100 |
Step by step
Quick reference table
Results when only Calories (kcal) changes and everything else stays put.
| Calories (kcal) | Carbs (g) | Protein (g) | Fat (g) |
|---|---|---|---|
| 1,000 | 113 | 75 | 28 |
| 1,500 | 169 | 113 | 42 |
| 2,000 | 225 | 150 | 56 |
| 3,000 | 338 | 225 | 83 |
| 4,000 | 450 | 300 | 111 |
What each result means
| Result | At default values |
|---|---|
| Carbs (g)Grams of carbohydrate for the day; each gram is 4 kcal. | 225 |
| Protein (g)Grams of protein for the day; each gram is 4 kcal. | 150 |
| Fat (g)Grams of fat for the day; at 9 kcal a gram it is the densest. | 56 |
Common mistakes
Most guidance keeps fat at 20% or more — it is needed for hormone synthesis and fat-soluble vitamin absorption.
Glossary
- Calories
- Energy, in kilocalories.
- A share
- The percentage that applies to the first item.
- B share
- The percentage that applies to the second item.
- Carbs
- Grams of carbohydrate for the day; each gram is 4 kcal.
- Protein
- Grams of protein for the day; each gram is 4 kcal.
- Fat
- Grams of fat for the day; at 9 kcal a gram it is the densest.
Frequently asked questions
Q. How is Macro Split Calculator calculated?
Carbs = Calories × A share ÷ 100 ÷ 4, Fat = Calories × (100 − A share − B share) ÷ 100 ÷ 9 — Carbs and protein give 4 kcal per gram, fat gives 9. Choose the percentages and this converts them to grams.
Q. Can you walk through an example?
With Calories 2,000kcal, A share 45%, B share 30%, the answer is Carbs 225g.
Q. What do I need to enter?
Enter Calories, A share, B share. The result recalculates as you type, and an empty box counts as zero.
Q. How much does the answer move if I change a number?
Changing only Calories (kcal) moves the answer to Calories (kcal) 1,000 → Carbs (g) 113 and Calories (kcal) 4,000 → Carbs (g) 450. The table below lays out five steps.
Q. How are the numbers rounded?
Money is shown to the nearest whole unit, percentages to one decimal place and everything else to two. What you see is rounded; the calculation itself carries the unrounded value forward.
Q. Anything to watch out for?
Most guidance keeps fat at 20% or more — it is needed for hormone synthesis and fat-soluble vitamin absorption.
Related calculators
These calculators help you understand health figures; they do not replace diagnosis or prescription. See a clinician if you have symptoms.