Macronutrient Calculator
Daily nutrition arithmetic
Distribute a calorie target
Result
Calculation summary
Enter values to see the result
Macro preview
One calorie target, three energy sources
How to use this calculator
- 1Enter a daily calorie target, optionally copied from the BMR and TDEE calculator.
- 2Choose a transparent preset or enter custom protein, carbohydrate, and fat percentages totaling 100%.
- 3Review daily grams, calorie contribution, per-meal arithmetic, and the adult AMDR comparison.
Formula
grams = calories × percentage ÷ calories per gram
Protein and carbohydrate use 4 kcal/g; fat uses 9 kcal/g. Per-meal values divide daily grams evenly by the selected meal count.
Calculation steps
- Select or validate a percentage split totaling 100%.
- Allocate daily calories to each nutrient and convert energy to grams.
- Divide grams by meal count and compare percentages with adult AMDR reference ranges.
Worked example
At 2,000 kcal with a 25% protein, 45% carbohydrate, and 30% fat split, the arithmetic allocation is 125 g protein, 225 g carbohydrate, and about 66.7 g fat.
Assumptions
- The calorie target is already appropriate for the user; this tool only distributes it mathematically.
- Food labels and tracking databases may round energy and grams, so logged totals may not reconcile exactly.
- Per-meal values assume an even split and do not prescribe meal timing.
- Pregnancy, breastfeeding, childhood, medical conditions, allergies, and performance nutrition require individualized guidance.
Sources
Frequently asked questions
What are the adult AMDR ranges?
The comparison uses 10–35% of energy from protein, 45–65% from carbohydrate, and 20–35% from fat. A value outside the range is flagged, not automatically rejected.
Why do grams not add up to calories at the same multiplier?
Protein and carbohydrate use about 4 kcal per gram, while fat uses about 9 kcal per gram.
Is the high-protein preset right for everyone?
No preset is an individualized recommendation. Medical history, training, preferences, and total diet quality matter.
Does the calculator include fiber?
It displays the common 14 g per 1,000 kcal reference separately, but fiber remains part of total carbohydrate labeling and is not a fourth calorie allocation.