Macro calculator
Calculator
The calculator needs JavaScript. The tables below give the same numbers for common cases.
How it is worked out
- Carbohydrate and protein provide about 4 kcal per gram and fat about 9 kcal per gram (the standard Atwater factors).
- Grams = calories × share ÷ calories per gram, for example carbohydrate: 2,000 × 40% ÷ 4 = 200 g.
- The split is a starting point you choose; it is not a prescription.
| Inputs | Answer |
|---|---|
| Daily calories: 2000; Split: 40 / 30 / 30 | At 2,000 calories and a 40 / 30 / 30 split: 200 g carbohydrate, 150 g protein and 67 g fat. |
| Daily calories: 2500; Split: 50 / 20 / 30 | At 2,500 calories and a 50 / 20 / 30 split: 313 g carbohydrate, 125 g protein and 83 g fat. |
| Daily calories: 1800; Split: 30 / 40 / 30 | At 1,800 calories and a 30 / 40 / 30 split: 135 g carbohydrate, 180 g protein and 60 g fat. |
How to use it
Macronutrients provide energy: carbohydrate and protein about 4 kilocalories per gram and fat about 9 (the standard Atwater factors). Choose a percentage split and the calculator converts it to grams, for example 2,000 calories at 40 / 30 / 30 is 200 g carbohydrate, 150 g protein and 67 g fat.
The splits are common starting points, not prescriptions. Official dietary guidance gives ranges for each macronutrient; individual needs differ. This is general information and an estimate, not medical advice; talk to a healthcare professional about your own situation.
Frequently asked questions
How do I calculate macros?
Multiply your calories by each percentage and divide by 4 (carbs, protein) or 9 (fat).
What macro split is best?
There is no single best split; it depends on your goals, preferences and health.
Why are fats 9 calories per gram?
Fat is more energy-dense than carbohydrate or protein, which have about 4.
Method: standard arithmetic shown step by step; no outside data is used. Checked 2026-11-12.
About · How we verify this · Editorial policy · Corrections
General information only. Results are plain arithmetic on the numbers you enter; check anything important (money, health, school work) against your own records or the official source.