Macro Calculator

Calories move the total; the split moves the plate

A calorie target says nothing about what lands on the plate, and a plate says nothing about the total — the macro split is the bridge between the two. This page takes a daily calorie figure and one of four common splits, then converts each nutrient's calorie share into grams using the energy densities nutrition labels are built on: 4 kcal per gram for protein and carbohydrate, 9 for fat. The output is three gram targets, plus the calories each one consumes, so a shopping list or a food-log day can be built directly from the panel.

The splits are starting points, not prescriptions. Balanced (30/40/30) suits a general-health week; high-protein (40/30/30) is the common choice when training hard and appetite runs high; low-carb (35/20/45) trades starch for fat to keep meals satisfying; endurance (25/55/20) front-loads carbohydrate for high-mileage weeks. The tool's job is to make whichever you pick arithmetically exact — the physiological judgement stays with you.

A worked example, step by step

Problem: 2,200 calories a day, balanced split. What does the plate look like in grams?

1. Protein: 30% of 2,200 = 660 kcal ÷ 4 = 165 g.
2. Carbs: 40% of 2,200 = 880 kcal ÷ 4 = 220 g.
3. Fat: 30% of 2,200 = 660 kcal ÷ 9 = 73.3 g.
4. Reality check on the fractions: fat's 9 kcal per gram means the same 660 kcal weighs only 73 g against protein's 165 g — that is energy density at work, not favouritism.
5. Other presets at a glance: high-protein 40/30/30 gives 220 g protein and 165 g carbs with the same 73 g fat; low-carb 35/20/45 gives 192.5 g, 110 g and 110 g.

The checks sum correctly by construction: 660 + 880 + 660 = 2,200 kcal, so the gram targets are internally consistent with the day — a property hand-splitting often loses.

The four presets at 2,200 kcal

Read the balanced row against the low-carb row and the trade is explicit: cutting carbs from 40% to 20% of the day removes 110 g of carbohydrate, while lifting fat from 30% to 45% adds only about 37 g — the 9 kcal per gram density does more work per gram, which is why low-carb plates look smaller and eat slower.

Grams are for shopping; the total is for trends

Body-weight trends follow the calorie total over weeks, not the daily gram gymnastics. The macro targets make the 2,200 kcal practical — they tell you a 165 g protein day is roughly two palm-size portions of meat or fish plus yogurt and legumes — but the weekly weigh-in arbitrates the number itself. A useful habit is to adjust the calorie input by results and re-run the split, keeping the food choices constant while the arithmetic moves.

Mistakes that quietly unbalance a split

• Reading the shares as grams. 30% protein is not 30% of the plate's weight; the 4-versus-9 kcal densities see to it.
• Adding alcohol silently. It carries 7 kcal per gram and appears in no preset; the tool's total is food-only.
• Comparing presets across different calorie totals. A low-carb 1,800 kcal day is not the low-carb row above; re-run the tool per target.
• Chasing sum-to-100 by hand. Rounding grams to whole numbers leaves a few kcal unaccounted; the panel's shares always sum to the input.

Keep exploring

• Calories Burned Calculator — the expenditure side of the same day's ledger.
• BMI Calculator — the weight-and-height frame the calorie target should serve.
• Daily Calorie Estimate — intake guidance, the number the split is built on.
• Guide: BMI and Calorie Estimates Explained.