Macro Calculator (Protein / Carbs / Fat)
Macronutrients — protein, carbohydrate and fat — are the energy-providing parts of food, each with a caloric density: protein and carbs give 4 kcal per gram, fat gives 9. A macro split turns a calorie target into gram targets for meal planning.
Enter your daily calorie target and a macro ratio (protein / carbs / fat as percentages). The calculator returns the grams of each macro.
It turns a daily calorie target into gram amounts for meal planning, so you know how much of each food group to put on the plate rather than just a total calorie ceiling.
Enter your values to see the result.
How this is calculated
Macronutrients — protein, carbohydrate and fat — are the energy-providing parts of food, each with a different caloric density: protein and carbohydrates supply 4 kcal per gram, fat supplies 9. This calculator takes a daily calorie target and a macro ratio (protein, carbs and fat as percentages), normalises the three percentages to sum to 100, then converts each share into grams by dividing its calories by the matching density.
A balanced starting point many people use is 30% protein, 40% carbs, 30% fat, but the right split depends on goals: endurance work favours more carbs, low-carb approaches raise fat, and muscle gain often raises protein. The calculator normalises whatever you enter, so any reasonable split works.
The model is pure energy arithmetic. It does not address food quality (whole grains versus refined, lean versus fatty protein), fibre, micronutrients, meal timing, or the satiety differences between macros. It also assumes the three percentages roughly sum to 100; wildly off totals produce skewed gram targets. Use it alongside the TDEE calculator to set the calorie total, and the protein calculator to sanity-check the protein gram figure.
Worked example
A 2,200 kcal daily target with a 30/40/30 protein/carbs/fat split.
- 1Protein calories = 2,200 × 0.30 = 660; grams = 660 ÷ 4 = 165 g.
- 2Carb calories = 2,200 × 0.40 = 880; grams = 880 ÷ 4 = 220 g.
- 3Fat calories = 2,200 × 0.30 = 660; grams = 660 ÷ 9 ≈ 73 g.
Frequently asked questions
- What macro ratio should I use?
- A balanced starting point is 30% protein, 40% carbs, 30% fat. Endurance athletes may favour more carbs; low-carb approaches raise fat. Adjust by goals and results.
- How much protein do I need?
- Most active adults benefit from 1.6–2.2 g of protein per kg of body weight per day. The protein calculator gives a tailored target.
- Are the three ratios required to total 100%?
- Yes. The calculator normalises them to 100% so any reasonable split works, but they should sum to about 100 for a sensible result.
- What macro ratio should I use?
- A balanced starting point is 30% protein, 40% carbs, 30% fat. Endurance athletes may favour more carbs; low-carb approaches raise fat. Adjust by your goals and the results you see over a few weeks.
- Are the three ratios required to total 100%?
- They should sum to about 100 for a sensible result. The calculator normalises them to 100% so any reasonable split works, but extreme totals produce skewed gram targets.
Related calculators
Method: calorie split converted to grams using 4/4/9 kcal per gram. No external data source. Last updated: September 2026.
These results are general estimates from established formulas and are not medical advice. They depend on the accuracy of the values you enter and on individual factors the formulas cannot capture. Consult a qualified healthcare professional before making decisions about your diet, training or treatment.