How to Count Macros: A Worked Day in Grams

To count macros, weigh each food, multiply its protein, fat and carbohydrate per 100 g by your portion, and add the foods up. Then compare the day’s totals with your targets. One food takes one multiplication. A full day takes a table, like the one below. The per-100 g figures come from a food record, such as cooked brown rice in USDA FoodData Central. New to the terms? Start with what macros are.

How do I calculate the macros in one food?

Here is the sum for 180 g of cooked brown rice, with the record’s figures in the first column and the arithmetic beside them.

Per 100 g (record)	× 180 g ÷ 100	Result
Protein 2.74 g	2.74 × 1.8	4.9 g
Fat 0.97 g	0.97 × 1.8	1.7 g
Carbohydrate 25.58 g	25.58 × 1.8	46.0 g
Energy 123 kcal	123 × 1.8	221 kcal

Ounces need one extra step. Multiply by 28.35 to get grams, then run the same sum, so a 6 oz portion becomes 170 g.

Weigh the food in the state the record names. A dry portion and a cooked portion of the same food are different entries. The raw brown rice record lists 368 kcal per 100 g, and the cooked one lists 123. Mix them up and you’re off by a factor of three.

How do I count macros in a recipe?

Add up every ingredient, weigh the finished pot, then work out the pot per 100 g. Here is a lentil and chicken pot. Each ingredient has its own record.

Ingredient	Grams	Protein	Fat	Carbs	kcal
Chicken breast, braised	400 g	128.4 g	13.0 g	0.0 g	664
Lentils, boiled	800 g	72.2 g	3.0 g	161.0 g	928
Baby spinach, raw	240 g	6.8 g	1.5 g	5.8 g	50
Crushed tomatoes, canned	400 g	5.8 g	1.6 g	28.5 g	129
Olive oil	20 g	0.0 g	20.0 g	0.0 g	177
Pot total	1,860 g	213.2 g	39.1 g	195.4 g	1,948

The ingredients total 213.2 g of protein, 39.1 g of fat, 195.4 g of carbohydrate and 1,948 kcal. Simmering drives off water, so the finished pot weighs less than its ingredients. Say it reads 1,720 g on the scale. Divide each total by 17.2 and you have the pot per 100 g. That’s 12.4 g of protein, 2.3 g of fat, 11.4 g of carbohydrate and 113 kcal.

A 350 g plate then holds 43.4 g of protein, 8.0 g of fat, 39.8 g of carbohydrate and 396 kcal. Spoon out whatever you like, weigh it, and multiply.

The pot’s weight on the scale is the number that makes this work. Without it you would be dividing by the number of bowls, and my bowls never come out the same size.

How do I count macros for a whole day?

Set targets first, then log against them. For the example I’ll use 2,000 kcal with 120 g of protein, 67 g of fat and 230 g of carbohydrate. The protein figure is 1.6 g per kg for a 75 kg adult, the top of the 2025–2030 Dietary Guidelines range of 1.2–1.6 g/kg. Fat is 30% of calories: 600 kcal, and 600 ÷ 9 gives 67 g. Carbohydrate takes the rest: 2,000 − 480 − 600 = 920 kcal, and 920 ÷ 4 gives 230 g. Picking your own split is covered in what your macros should be. To get yours, use the macro calculator. It turns a calorie goal into grams of protein, fat and carbohydrate.

Now the day. Each row is one food, weighed in the state shown, with figures from its USDA record.

Meal	Food and grams	Protein	Fat	Carbs	kcal
Breakfast	Rolled oats, dry, 50 g	6.7 g	2.9 g	34.3 g	189
Breakfast	Banana, 115 g	0.9 g	0.3 g	26.4 g	101
Breakfast	Greek yogurt, plain, nonfat, 150 g	15.5 g	0.6 g	5.5 g	92
Breakfast	Almonds, raw, 10 g	2.1 g	5.1 g	2.0 g	58
Lunch	Chicken breast, braised, 120 g	38.5 g	3.9 g	0.0 g	199
Lunch	Brown rice, cooked, 180 g	4.9 g	1.7 g	46.0 g	221
Lunch	Broccoli, raw, 150 g	3.9 g	0.5 g	9.4 g	48
Lunch	Olive oil, 5 g	0.0 g	5.0 g	0.0 g	44
Snack	Gala apple, raw, 150 g	0.2 g	0.2 g	22.2 g	82
Snack	Almonds, raw, 15 g	3.2 g	7.7 g	3.0 g	88
Dinner	Atlantic salmon, farmed, raw, 120 g	24.4 g	15.7 g	0.0 g	244
Dinner	Sweet potato, peeled, raw, 200 g	3.2 g	0.8 g	34.7 g	155
Dinner	Baby spinach, raw, 60 g	1.7 g	0.4 g	1.4 g	12
Dinner	Olive oil, 5 g	0.0 g	5.0 g	0.0 g	44
Total		105.2 g	49.8 g	185.0 g	1578

The day lands at 105.2 g of protein, 49.8 g of fat, 185.0 g of carbohydrate and 1,578 kcal. Set against the targets, that leaves 14.8 g of protein, 17.2 g of fat, 45.0 g of carbohydrate and 422 kcal.

	Protein	Fat	Carbs	kcal
Target	120 g	67 g	230 g	2,000
Logged	105.2 g	49.8 g	185.0 g	1,578
Left	14.8 g	17.2 g	45.0 g	422

Protein is the gap that matters. One 156 g tub of Greek yogurt adds 16.1 g of protein and 95 kcal, which closes it. I treat the Left row as the brief for the rest of the day.

Read the log by meal as well as by total. Breakfast gave 25.2 g of protein, lunch 47.3 g, dinner 29.3 g and the snack 3.4 g. Lunch carried 45% of the day’s protein and the snack 3%. If a day runs short, that tells you which meal to change first.

Watch the oil. In this day, 10 g of olive oil is 88 kcal. A full tablespoon of 13.5 g is 119 kcal, so weigh the oil before it goes in the pan.

Which numbers should I trust: the label, an app or my own math?

Start with the label when you eat packaged food, and with a database record when you don’t. The NHS says UK labels give figures per 100 g, sometimes per portion. It warns that the maker’s idea of a portion may differ from yours. Read per 100 g. Weigh your own portion.

I trust records from national food tables over entries typed by other users. When an app offers six versions of the same food, pick the one that names its state and source. If the figures look odd, compare them with the USDA record for the same food.

Food with no label and no record, such as a restaurant plate, gets an estimate. Pick the closest record, weigh what you can, and mark the entry as a guess so you don’t treat it as a measurement.

Two traps cause drift. The first is state: raw and cooked, as above. The second is the 4, 9 and 4 shortcut. Here the day’s protein, fat and carbohydrate sum to 1,609 kcal at 4, 9 and 4 per gram, while the records list 1,578 kcal. That’s a 2% gap, because records use food-specific energy factors. Log the listed figure and use the sum only as a sanity check, the way I did across eight records in protein calories per gram.

How close do my macros need to be?

Closer on protein than on the other two. Protein is the one target with a body-weight formula behind it, the 1.2–1.6 g/kg range. My rule is a weekly average within 10% of the protein target, so 108–132 g against 120 g. Fat and carbohydrate trade places from day to day without much cost, so I watch them loosely.

A single day that misses by 20 g either way is normal, and I leave it alone instead of eating a spoonful of peanut butter at 10 pm to fix the arithmetic. The weekly average is the number I read.

For today, weigh just one meal. Dinner is the easiest, because it’s the meal you control most. Log it in grams and read the three numbers. Do that for a week before you decide whether full counting is worth it. If the aim is weight loss, how to count macros for weight loss starts from the calorie goal.

Who shouldn’t count macros?

Ask your doctor before setting gram targets if you have kidney disease, are pregnant or breastfeeding, or are under 18, since a calculator can’t set protein for any of those situations.

Weighing every gram can also start to run your day. If you notice that happening, I’d drop back to calories alone or pause for a few weeks, and the log will still be there when you return.

If counting calories has started to feel hard to stop, or eating feels out of control, talk to someone: ANAD in the US (1-888-375-7767), Beat in England (0808 801 0677), NEDIC in Canada (1-866-633-4220) or the Butterfly Foundation in Australia (1800 33 4673). If you’re in danger right now, call your local emergency number. Other UK numbers and crisis lines are on our crisis support page.