Macros (macronutrients) are the three main nutrients that give you calories: protein, carbohydrate and fat. To work out your macros, start with a daily calorie target, choose a split such as 50% carbs, 20% protein and 30% fat, then divide each share by its calories per gram. A 2,000 kcal day on that split is about 250 g of carbs, 100 g of protein and 67 g of fat.
The three macronutrients and their calories
| Nutrient | Calories per gram |
|---|---|
| Protein | 4 kcal |
| Carbohydrate | 4 kcal |
| Fat | 9 kcal |
Alcohol also provides 7 kcal per gram, though it is not counted as a macro. Fat is more than twice as calorie-dense as the others, which is why small amounts add up fast.
What each macro does
- Protein helps build and repair tissue, including muscle. Good sources include meat, fish, eggs, dairy, beans, lentils and tofu.
- Carbohydrate is the body’s main fuel, especially for exercise. It comes from foods such as bread, rice, pasta, potatoes, fruit and oats.
- Fat supports hormones, absorbing some vitamins and keeping you full. Sources include oils, nuts, seeds, oily fish and avocado.
Step 1: find your calorie target
Macros are shares of a calorie total, so start there. If you do not know your needs, Calories and TDEE: how many calories do you need? shows how to estimate your daily calories from your size, age and activity.
Step 2: choose a split and do the sums
The Calories and macros tool offers several common splits. For 2,000 kcal a day:
| Split | Carbs | Protein | Fat |
|---|---|---|---|
| Balanced (50/20/30) | 250 g | 100 g | 67 g |
| High protein (40/30/30) | 200 g | 150 g | 67 g |
The sums for the balanced row: 50% of 2,000 is 1,000 kcal, and 1,000 ÷ 4 = 250 g of carbs. Protein is 400 kcal ÷ 4 = 100 g. Fat is 600 kcal ÷ 9 = 67 g (rounded). Split over three meals, that is roughly 83 g carbs, 33 g protein and 22 g fat per meal.
The tool also includes lower-carb, lower-fat and endurance splits. There is no single best ratio: the right one depends on your activity, preferences, health and goals.
Practical tips for beginners
- Do not chase exact numbers. Treat grams as a guide and aim to be in the right area most days.
- Build meals around a protein source, add a carbohydrate and some vegetables, then include a modest amount of fat.
- Use food labels to check grams per portion, and weigh foods for a week or two to learn what portions look like.
- Pair macros with the basics: fibre, fruit and vegetables, fluids (see How much water should you drink each day?) and enough sleep.
- Review after two to four weeks and adjust, rather than changing things daily.
Note: This is general information, not medical or dietary advice. If you have diabetes, kidney problems, a food allergy, are pregnant or have had an eating disorder, speak to a GP or registered dietitian before changing how you eat.
Do macros matter more than calories?
For weight change, total calories matter most. Macros help shape how that food feels and what it supports, such as protein for muscle or carbohydrate for training. Weight alone is a limited measure, so you may also want to read BMI explained: what it tells you and what it doesn't to see what BMI can and cannot show.
Example day on a balanced split
Here is how 2,000 kcal might look in practice on the balanced split, as a guide only:
- Breakfast: porridge with milk and a banana, plus an egg, for carbs and some protein
- Lunch: a chicken or bean wrap with salad and a piece of fruit
- Dinner: salmon or tofu with rice and vegetables, cooked in a little oil
- Snacks: yoghurt, a handful of nuts or fruit, which mostly add protein and fat
Add up the grams from the labels and compare them with your targets. If protein is low, add a portion at one meal; if fat is high, trim oils or spreads.
Try the calculator
Use Calories and macros to turn a calorie target into grams per day and per meal, and Calorie and TDEE to estimate that target first. Results are estimates, not a prescription.
Open the free Calories and macros
Frequently asked questions
What are macros in simple terms?
They are protein, carbohydrate and fat, the nutrients that supply your calories. Tracking them means counting grams of each rather than just total calories.
How much protein do I need?
It varies with your size, activity and goals. The 20% to 30% shares used in the tool are starting points, and a dietitian can give a personal figure.
Do I need to count macros to lose weight?
No. A calorie deficit is the main driver, and many people succeed with portion awareness alone. Macros are an optional extra.
Why does fat have more calories per gram?
Fat stores more energy per gram: 9 kcal against 4 kcal for protein and carbohydrate. That is why small portions of oils and nuts add up quickly.