Macro Calculator

The tool divides a calorie figure you already have. It does not work out how many calories you need, so decide that first, for instance with a calorie calculator.

1. Type your target in Daily calories, in kilocalories, the unit used on food labels in most countries.
2. Pick a Split: Balanced (40/30/30), Endurance (60/15/25), High protein (30/40/30), Low carb (20/35/45), Keto (5/20/75) or Custom percentages. The order of each preset is carbs, protein, fat.
3. If you chose Custom, fill in Custom: carbs (%), Custom: protein (%) and Custom: fat (%). They must total exactly 100, otherwise the tool tells you what they add up to instead of showing a result.
4. Set Meals per day to see how many grams land on each plate.
5. Read the daily grams in the headline, then the table of calories, share and grams per meal for each macro, and the proportion bar underneath.

The preset names are shorthand for a style of eating, not a promise about results. If a preset is close to what you want, choose it and then switch to Custom to nudge individual percentages, remembering that the three values must still total 100.

Protein and carbohydrate each supply about 4 kilocalories per gram, and fat supplies 9. The grams for each macro are therefore the calories multiplied by its share, divided by its energy per gram. This calculation is simple enough to check by hand.

Take 2,000 kcal on the Balanced split. Protein is 2,000 x 30% / 4 = 150 g. Carbohydrate is 2,000 x 40% / 4 = 200 g. Fat is 2,000 x 30% / 9 = 66.7, shown as 67 g. With three meals a day that is 50 g of protein, 67 g of carbohydrate and 22 g of fat per meal. Grams are rounded for display, so adding them back (150 x 4 + 200 x 4 + 67 x 9) gives 2,003 kcal, a few calories off the target.

For comparison, here is what 2,000 kcal looks like on every preset:

Notice how large the fat figure looks on the Keto split: it is only 75 percent of the calories, but each gram of fat carries more than twice the energy of a gram of carbohydrate, so the grams stay modest relative to the share.

Percentages describe proportions, not needs. The same 30 percent protein is roughly 110 g at 1,500 kcal and 225 g at 3,000 kcal, and actual protein requirements depend on body weight, training and goals more than on the calorie total. Many people set protein first from their body weight and let the other two macros fill what remains, which is exactly what the Custom option lets you do. Endurance athletes tend to lean on the carbohydrate-heavy presets, while the lower carbohydrate options trade that for more fat and protein.

Be clear about what the tool leaves out. It counts only the three macronutrients, so fibre, alcohol and the calories in drinks are not modelled separately, and it offers a division of calories, not a menu. It cannot know about allergies, medical conditions or cultural food patterns. Per-meal figures are simply the daily grams divided evenly by the number of meals, so if your meals are uneven, treat them as an average and adjust by hand.

One practical habit is to compare the tool output with the labels on the food you actually buy. Labels list grams of each macronutrient per serving, so adding up a day of labels and comparing the totals with the table here is a direct way to see whether a plan is realistic before you commit to it.

The output is general guidance and is not a personalised diet plan or medical advice. People with a medical condition, who are pregnant or who have a history of disordered eating should follow advice from a qualified professional. To explore related numbers, see the body fat calculator for body composition, the BMI calculator for a quick weight-to-height check, and the energy converter if your food labels use kilojoules rather than kilocalories.