Macro Calculator
Macro Calculator
Turn a calorie target into grams of protein, carbohydrate and fat. Most macro calculators hand you a 40/30/30 split with no explanation. This one sets protein first, from your body weight and your goal, against what the research actually found, then divides what is left between carbs and fat according to how you like to eat. It also shows what the split looks like meal by meal, which is the number you can act on.
Where the calories go
Your protein against the evidence
Calories per gram use the conventional Atwater figures: 4 for protein, 4 for carbohydrate, 9 for fat and 7 for alcohol. The protein targets here come from the 2018 meta analysis in the British Journal of Sports Medicine by Morton and colleagues, which pooled 42 study arms and 723 participants and found training gains stopped improving above about 1.62 grams per kilogram a day, with those authors suggesting about 2.2 as a prudent ceiling once the uncertainty is allowed for. The higher cutting figures follow the 2014 review by Helms and colleagues, which recommends 2.3 to 3.1 grams per kilogram of lean mass for lean people in a deficit. Fat is held at a floor because very low fat intakes are hard to sustain and provide the fat soluble vitamins. This is general information, not medical or dietetic advice. The CSV, image and printed report contain the values you entered, nothing preloaded.
How to use this tool
You need two numbers to start: your daily calorie target and your body weight. If you do not have a calorie target, work it out on the TDEE calculator first, because macros divide a calorie budget and cannot tell you what that budget should be. Then pick the goal and the eating style, and the split appears.
The goal box is doing more work than it looks. It sets the protein target, and the direction is the opposite of what people expect: protein goes up on a cut, not down. When you are in a deficit your body is looking for tissue to break down, and a high protein intake is most of what decides whether it takes fat or muscle. In a surplus the same logic barely applies, which is why the gain setting asks for less.
The eating style box does not affect protein at all. It only decides how the calories left over after protein are divided between carbohydrate and fat, and that division is almost entirely a matter of preference and of how hard you train. There is no research finding a best ratio for body composition at a fixed calorie and protein intake, which is worth saying plainly because a great many pages imply otherwise.
If you know your body fat percentage, type it in. Protein then comes from lean mass rather than total weight, which is the better anchor once you have a real measurement, and it matters most for people carrying a lot of fat, where a target set from total weight overshoots. The per meal panel is the number to actually use, since nobody eats a day of food in one go.
Protein first, and why
Of the three macronutrients, protein is the only one with a target that comes from experiments rather than from convention. In 2018 Morton and colleagues published a meta analysis in the British Journal of Sports Medicine pooling 42 study arms and 723 participants, and their meta regression found a break point at 1.62 grams per kilogram of body weight a day: above that, more protein produced no further gains in fat free mass from resistance training.
The confidence interval around that break point ran from 1.03 to 2.20, which is wide, and the authors were honest about it. Their own suggestion was that about 2.2 grams per kilogram a day is a prudent figure for someone wanting to be sure they are not leaving anything on the table. That is the upper end of the teal band on the chart, and it is where the cut setting on this page puts you.
For people who are already lean and in a deficit, the recommendations go higher still. The 2014 review by Helms and colleagues in the Journal of the International Society of Sports Nutrition recommends 2.3 to 3.1 grams per kilogram of lean body mass for natural bodybuilders in contest preparation, on the grounds that the leaner you get the more your body is willing to break down muscle. That is a specific situation, not a general recommendation, and it is why this page only reaches those numbers when you give it a low body fat figure.
The problem with 40/30/30 and every other fixed ratio
Percentage splits are the standard way macros are handed out, and they are structurally wrong for the one macro that matters. Protein requirements scale with how much body you have. Calorie requirements scale with body size too, but not in the same proportion, and they move with activity in a way protein does not.
Work it through. A 50 kg woman and a 100 kg man both eating 2,000 calories on a 40/30/30 split each get 150 grams of protein. For her that is 3 grams per kilogram, well above anything the research supports and a large chunk of her day spent on protein she does not need. For him it is 1.5 grams per kilogram, below the plateau, and if he is cutting it is not enough. The same ratio, applied honestly, gives one person too much and the other too little.
The fix is simply to work in the right units. Set protein in grams per kilogram of body weight, which is how every study that produced these numbers measured it. The percentage split then comes out as a consequence rather than as an input, and it will be different for different people, which is the point.
Common calorie and weight combinations
Exact arithmetic on a cut with a balanced style. Notice how the percentage split shifts across the rows even though the method is identical, which is what a fixed ratio cannot do.
| Calories and weight | Protein | Carbs | Fat | Per kg protein | Split |
|---|---|---|---|---|---|
| 1,500 kcal at 60 kg | 132 g | 138 g | 47 g | 2.20 | 35/37/28 |
| 1,800 kcal at 70 kg | 154 g | 170 g | 56 g | 2.20 | 34/38/28 |
| 2,000 kcal at 65 kg | 143 g | 217 g | 62 g | 2.20 | 29/43/28 |
| 2,200 kcal at 82 kg | 180 g | 216 g | 68 g | 2.20 | 33/39/28 |
| 2,500 kcal at 82 kg | 180 g | 270 g | 78 g | 2.20 | 29/43/28 |
| 2,800 kcal at 90 kg | 198 g | 306 g | 87 g | 2.20 | 28/44/28 |
| 3,200 kcal at 95 kg | 209 g | 367 g | 100 g | 2.20 | 26/46/28 |
On a cut with a balanced style. Every row is a link that opens the calculator on that combination.
Carbohydrate and fat, or why this part is preference
Once protein is set and calories are fixed, carbohydrate and fat are trading against each other, and the research on where that trade should land for body composition is thin. Controlled studies that match calories and protein generally find little to separate high carb from low carb diets for fat loss. What does differ is how people feel, how well they train, and how long they stick with it, and those are not small things.
There are two practical floors. Fat should not drop below about 20 percent of calories for long: it carries the fat soluble vitamins, it has a role in hormone production, and very low fat eating is miserable to sustain. Carbohydrate should not drop so low that hard training falls apart, unless you have deliberately chosen a very low carb approach and given yourself a few weeks to adapt. The calculator holds a fat floor for you and will tell you when the carbohydrate figure has got unreasonably low for the style you picked.
Beyond those floors, pick what you will actually eat. If you train heavily, push carbohydrate up. If you are happier on fattier food and find it more filling, push fat up. The scale will not notice the difference; your adherence will.
A worked check you can repeat on paper
Take 2,200 calories a day at 180 lb on a cut. 180 lb is 81.65 kg. The cut setting uses 2.2 grams per kilogram, so protein is 81.65 times 2.2, which is 179.6 grams, shown as 180. At 4 calories a gram that is 718 calories, or 33 percent of the total.
Fat on the balanced style is 28 percent of calories, so 2,200 times 0.28 is 616 calories, and at 9 calories a gram that is 68.4 grams, shown as 68. Carbohydrate takes what is left: 2,200 minus 718 minus 616 is 866 calories, and at 4 calories a gram that is 216.5 grams, shown as 216. Add the three back up, 718 plus 866 plus 616, and you get 2,200, which is where you started.
Now the per meal figure, which is the one you can act on. Across three meals that is 60 grams of protein, 72 of carbohydrate and 23 of fat in each, and 733 calories. Sixty grams of protein is roughly 200 grams of chicken breast, or a large tin of tuna and a pot of Greek yogurt, or two scoops of whey and three eggs. That is what the number means in food, and it is the translation most calculators leave out.
Mistakes that catch people out
Setting macros before calories. The split divides a budget. Work out the budget first, on the TDEE calculator or from your own weight trend, and then divide it.
Dropping protein on a cut. The opposite of what you want. Protein is the macro that decides whether the weight coming off is fat or muscle.
Chasing a percentage split. A ratio cannot be right for two people of different sizes eating the same calories. Grams per kilogram can.
Eating protein in one enormous meal. Three to five servings of roughly 0.4 grams per kilogram spread across the day does more for muscle protein synthesis than one large dose.
Cutting fat to almost nothing to make the carbs fit. Below about 20 percent of calories you are trading away vitamins, hormone substrate and most of the pleasure of eating for very little.
Re weighing the plan every few days. Macros are a fortnightly experiment, not a daily one. Set them, run them for two or three weeks, look at the weekly average weight, and adjust calories before you adjust ratios.
Popular macro splits
The calorie and weight combinations people look up most. Each opens the calculator on that pair with its own address.
By calorie level
By body weight, pounds
By body weight, kilograms
Maintaining and gaining
Other eating styles
How this was checked
The split was tested in Node across every combination of goal, eating style, calorie level from 700 to 6,000 and body weight from 40 to 200 kilograms, and in every case the three macronutrients multiplied by their Atwater factors add back to the calorie target exactly. The edge cases were checked deliberately: a very low calorie target with a high protein setting, where protein is capped at 60 percent of calories rather than allowed to exceed the budget; a very low carb style, where carbohydrate is pinned near 25 grams and fat takes the remainder instead of carbohydrate going negative; and a fat percentage below the floor for the chosen goal, where the floor is applied and carbohydrate absorbs the difference.
The protein figures were taken from the primary sources rather than from secondary summaries: the 1.62 grams per kilogram break point and its 1.03 to 2.20 confidence interval from the 2018 Morton meta analysis, and the 2.3 to 3.1 grams per kilogram of lean mass from the 2014 Helms review. The lean mass path was checked against the body weight path at a range of body fat percentages to confirm it crosses over where it should, giving a higher target for lean people and a lower one for people carrying more fat. The live page was then opened at every address linked above and each was checked for a distinct title, the right headline, charts that rendered, and clean CSV, image and print output containing only that combination, at desktop, tablet and phone widths.
Common questions
How do I calculate my macros?
In three steps, and the order matters. Set protein first from your body weight, because it is the one macro with a research backed target: about 1.6 to 2.2 grams per kilogram a day depending on your goal. Set fat next as a percentage of calories, somewhere between 20 and 35 depending on what you enjoy eating, with a floor because very low fat diets are hard to keep up. Whatever calories are left go to carbohydrate. Protein and carbohydrate are 4 calories a gram, fat is 9, and the three must add back to your calorie target.
How much protein do I actually need?
More than the RDA, less than the internet says. The RDA of 0.8 grams per kilogram is set to prevent deficiency, not to build anything. The 2018 meta analysis by Morton and colleagues in the British Journal of Sports Medicine pooled 42 study arms and 723 participants and found the gains from resistance training stopped improving above about 1.62 grams per kilogram a day. The confidence interval was wide, so those same authors suggested about 2.2 as a prudent ceiling. On a cut, where protein protects muscle while you are in a deficit, the higher end is worth having. Above about 2.2 you are eating protein instead of something else, not in addition to it.
Is 40/30/30 a good macro split?
It is a number somebody made up in the nineties and it has been copied ever since. The problem is not that the ratios are wrong, it is that a ratio cannot be right, because protein needs scale with your body weight and calories do not. A 50 kg person and a 100 kg person eating 2,000 calories each on a 40/30/30 split both get 150 grams of protein, which is generous for one and inadequate for the other. Set protein in grams per kilogram and let the ratio fall out of that.
What should my macros be to lose fat?
Calories decide whether you lose fat; macros decide what you lose. Set the calorie deficit first, then push protein towards the top of the range, around 2.2 grams per kilogram of body weight or 2.3 to 3.1 per kilogram of lean mass if you know your body fat, because that is what keeps muscle on you while the fat comes off. Keep fat above about 20 percent of calories and let carbohydrate take the remainder. If you are training hard, more of the remainder should be carbohydrate.
Do macros matter more than calories?
No. Calories decide the direction of the scale, and nothing in the macro split changes that. What macros change is the composition of what you gain or lose and how the diet feels day to day. Enough protein means more of the weight you lose is fat rather than muscle, and more of the weight you gain is muscle rather than fat. Enough carbohydrate means your training sessions do not fall apart. Enough fat means you can stay on the plan. Get calories right first and treat the split as the second order problem it is.
How should I split macros across meals?
Evenly is a reasonable default and the calculator does that, but the protein research is more specific than the rest. Spreading protein across three to five meals of roughly 0.4 grams per kilogram each gives a better muscle protein synthesis response than one enormous serving and two small ones. Carbohydrate is more flexible and is worth concentrating around training if you train hard. Fat is the most flexible of all and mostly follows whatever the meal happens to contain.
Related Calculators and Reference
- TDEE Calculator: the calorie target this page divides up, with every formula and activity level compared.
- Body Fat Calculator: the body fat figure that lets this page set protein from lean mass instead of total weight.
- One Rep Max Calculator: for the training the protein target is there to support.
- Steps to Miles Converter: the activity side of the budget, turning a step count into distance and energy.
- Grams to Ounces Converter: for weighing food when the packet is in ounces and the target is in grams.
- Percentage Calculator: for the percentage splits and the week to week adjustments.
- Calorie Deficit Calculator: a daily calorie target and a realistic date for a goal weight.
- Protein Intake Calculator: grams of protein a day for your weight and goal.
- Morton and others, British Journal of Sports Medicine 2018: the meta analysis the protein plateau on this page comes from.