How to work out your macros
- Let the calculator Work out your calories from your body and activity, or choose I know my target and type it.
- Pick a Goal and a Split. Choose Custom to set your own protein and fat percentages; carbs take the rest.
- Read your grams of protein, carbs and fat a day, and the amounts per meal underneath.
How the numbers are worked out
When the calculator works out your calories, it uses the Mifflin-St Jeor equation for your resting rate, multiplies it by your activity level and then adds or takes away calories for your goal: 550 a day for about 0.5 kg (1 lb) a week and 275 for about 0.25 kg (0.5 lb). The total is rounded to the nearest 10.
For the default example, a 35-year-old woman of 168 cm and 68 kg who exercises 3 to 5 days a week needs about 2,160 calories to keep her weight. With the balanced split that is:
| Macro | Share | Calories | Grams |
|---|---|---|---|
| Protein | 20% | 432 | 108 g |
| Carbohydrates | 50% | 1,080 | 270 g |
| Fat | 30% | 648 | 72 g |
Choosing a split
A balanced split suits most people and matches the ranges in the US Dietary Reference Intakes. A higher protein share can help you feel full while eating less, and many people who lift weights use one. Lower carb splits shift calories to fat and protein, which some people find easier to stick to. Whichever you pick, total calories decide whether you lose or gain weight; the split changes what those calories are made of.
Tracking macros in practice
Food labels list grams of protein, carbohydrate and fat per serving, and most food tracking apps add them up for you. Aim to land near your targets over a day or a week rather than hitting them exactly at every meal.