Macronutrient Calculator
Split a daily calorie target into grams and calories of protein, carbs and fat using a diet preset (balanced, high-protein, keto, endurance or zone) or a custom macro ratio, with an optional per-meal breakdown.
Input
Your TDEE or a target calorie level — estimate it with the BMR & TDEE Calculator if unsure.
Choose a preset, or pick Custom to set your own split.
Used for the per-meal breakdown.
Output
| Macro | Grams / day | Calories | % of Calories |
|---|---|---|---|
| No data yet | |||
| Macro | Grams / meal | Calories / meal |
|---|---|---|
| No data yet | ||
Guides
The Macronutrient Calculator turns a daily calorie target into a concrete plan for how many grams of protein, carbohydrate and fat to eat — and how many calories each of those macros contributes. Enter your calorie goal, pick a diet style, and the tool splits the total across the three macronutrients instantly, then breaks it down per meal so you know what each plate should look like.
What are macronutrients?
Macronutrients ("macros") are the three nutrients that supply energy: protein, carbohydrate and fat. Their energy densities are fixed by the Atwater system:
- Protein — 4 calories per gram
- Carbohydrate — 4 calories per gram
- Fat — 9 calories per gram
Because fat carries more than twice the calories of protein or carbs gram-for-gram, a "high-fat" diet like keto has far fewer total grams of food-energy per calorie than a carb-heavy endurance diet. This calculator handles that conversion for you, so you never have to multiply percentages by energy factors by hand.
How to use it
- Enter your daily calorie goal. This is usually your maintenance calories (TDEE), or that number adjusted up for a bulk or down for a cut. If you don't know it, estimate it first with the BMR & TDEE Calculator, then bring the figure here.
- Choose a diet preset, or select Custom to set your own protein/carb/fat percentages with the sliders:
- Balanced — 30% protein / 40% carbs / 30% fat. A sensible default for general health.
- High Protein — 40 / 35 / 25. Favoured for muscle retention while cutting.
- Keto / Low Carb — 25 / 5 / 70. Very low carbohydrate, high fat.
- Endurance — 20 / 60 / 20. Carb-forward for long-duration training.
- Zone — 30 / 40 / 30. The classic Zone-diet ratio.
- Set meals per day to see how the daily totals divide across each meal.
The results appear as two tables: a daily breakdown (grams, calories and the percentage each macro contributes) with a Total row, and a per-meal breakdown. Both are copyable and downloadable as CSV.
Do my percentages have to add up to 100?
No. When you use Custom, the calculator normalizes whatever three numbers you enter by their own sum, so the macro calories always add back up to exactly your calorie goal. If you enter 40/40/40, it treats that as an even three-way split. The built-in presets already total 100%.
Why don't the rounded grams multiply back to a round calorie figure?
Grams and calories are each rounded to whole numbers independently for readability, so a rounded gram figure times its energy factor can differ from the displayed calories by a calorie or two. The Total row always reflects your original calorie goal.
A note on estimates
This tool provides general nutritional estimates for educational purposes only. It is not medical or dietary advice, and individual needs vary with body composition, health conditions, training and goals. Consult a registered dietitian or physician before making significant changes to your diet.