Macro calculator
Your protein, fat and carbs — and the calorie number they were split from.
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Your likely daily energy use
2,041 as low as
2,430 kcal/day
2,819 as high as
±16% — the shaded band is where your real figure most likely sits.
Show the arithmetic
- BMR (Mifflin-St Jeor)
- 10(82) + 6.25(178) − 5(34) + 5 = 1768 kcal
- Activity — Lightly active
- 1768 × 1.375 = 2430 kcal
- Honest band — ±16%
- 2041 – 2819 kcal/day
Mifflin-St Jeor is the default because it is the best-validated equation that needs no body-fat number. Harris-Benedict would give 1,848 kcal for the same person — a difference of well under 100 kcal. The formula is not what makes these calculators wrong; the activity multiplier is.
Your calorie target, then your macros
Macros are a split of a calorie number, so the calorie number comes first. Moderate loss is marked because it is the rate most people actually sustain — pick another row and the grams below follow it.
Clamped. A target below 1,500 kcal is not something to run unsupervised, so we show the floor instead of the number the percentage asked for.
1,944 kcal/day · -0.44 kg per week, estimated
Your macros — as ranges, because that is what the evidence supports
- Protein 148–180 g 1.6–2.2 g per kg bodyweight, upper end while cutting
- Fat 43–65 g 20–30% of calories
- Carbs 160–241 g whatever the calorie target has left
How to replace this estimate with your own number
Every figure on this page is a starting point, and the ±band is the honest size of the error. After two to three weeks of eating near your target, weigh yourself daily and compare the weekly averages, not single days. If the average moved less than the estimate predicted, your real maintenance is lower than shown — subtract roughly 100 kcal and hold for another fortnight. If it moved faster, add 100. Two cycles of that beat any formula, including this one.
What this free macro calculator actually does
It works out how many calories you burn in a day, shifts that number for the goal you pick, and splits the result into grams of protein, fat and carbohydrate. Every macro calculator does those three things. The difference here is that all three are visible: the calorie estimate is shown as a range rather than a single confident figure, the formula that produced it is printed with your own numbers substituted, and the macro targets are given as ranges because a split of an uncertain number cannot be certain.
That ordering is not a design quirk — it is the actual dependency. Macros are a division of a calorie total, so if the calorie total is wrong by 300 kcal, every gram figure below it is wrong too, no matter how precisely it is printed. Most calculators hide this by displaying the split to the nearest gram. Getting the calorie number approximately right, and knowing how approximate it is, matters more than the ratio you choose.
How to calculate your macros, step by step
First, maintenance calories. An equation estimates your basal metabolic rate from your sex, age, height and weight, and that figure is multiplied by an activity factor between 1.2 and 1.9. This is the same calculation the TDEE calculator on the homepage performs, and it is where nearly all of the uncertainty lives.
Second, the goal shift. A deficit or surplus is applied as a percentage of maintenance rather than a flat number of calories, because a flat 500 kcal cut is mild for a large person and aggressive for a small one.
Third, the split. Protein is set from bodyweight, at 1.6–2.2 g per kilogram. Fat is set as 20–30% of the calorie target and converted at 9 kcal per gram. Carbohydrate is whatever remains, at 4 kcal per gram. Protein and fat are anchored to something real — your body and your energy intake — and carbohydrate absorbs the leftovers, which is why it is the number that swings most when you change goals.
Where each macro number comes from
Protein is the best-evidenced of the three. Intakes around 1.6 g per kilogram of bodyweight capture most of the benefit for people training with weights, with little further gain much beyond 2.2 g/kg; the upper part of that band is worth using while dieting, when adequate protein helps protect lean mass. Because the target scales with bodyweight rather than with calories, your protein figure barely moves when you change goal — which surprises people expecting it to fall in a cut.
Fat is expressed as a share of calories rather than per kilogram, with a floor worth respecting: dietary fat carries the fat-soluble vitamins and supports hormone production, so pushing it very low to make room for other things tends to cost more than it gains. Carbohydrate takes the remainder. It is not the least important macro — it is the most flexible one, and flexibility is what makes a target survive contact with real meals.
Why the targets are ranges, not exact grams
The calorie estimate underneath carries a band of roughly ±16%, narrowing to about ±11% if you have a measured body fat percentage to hand. Dividing a number that uncertain cannot produce a certain one. A macro calculator that returns "182 g carbohydrate" has not eliminated that error; it has painted over it, and the false precision invites you to chase a target that was never that exact.
So the ranges here are the honest width of the answer. Any value inside one is a reasonable target, and hitting the middle of your protein range across a week matters considerably more than hitting the top of it on Tuesday.
Setting a calorie deficit without guessing
For fat loss, 10–25% below maintenance is the usual working range, landing near 0.25–0.7% of bodyweight per week. Below about 1,200 kcal for women or 1,500 for men, this calculator shows the floor instead of the number the percentage asked for — those intakes are hard to meet nutritional needs on and are not something to run without supervision.
The more useful move, once you have a target, is to stop trusting it. Eat near it for two to three weeks, weigh yourself daily, and compare weekly averages rather than single days. If your weight moved less than predicted, your real maintenance is lower than the estimate — take about 100 kcal off and hold. Two cycles of that beat any equation, including this one, because your own weight trend is a measurement and the equation is only a prediction.
Cutting, maintaining and bulking
These are the same calculation with a different percentage, which is why they are goal settings in the tool above rather than separate pages. For a lean gain, roughly 10% above maintenance alongside resistance training is enough for most people, at around 0.25% of bodyweight per week; larger surpluses add fat rather than muscle, because the rate at which tissue can be built has a ceiling that eating more does not raise. In all three cases protein stays in the same band and carbohydrate absorbs the difference.
What a macro calculator cannot tell you
It cannot see your food quality, your fibre intake, your micronutrients, your sleep, or your medical history. Macros are an energy and body-composition tool, not a nutrition plan — a day can hit every target here and still be a poor day of eating. It also cannot account for conditions that affect metabolism or for medication that changes appetite or energy use.
This page is written by Madhu Kinnera, who is not a clinician — about this calculator explains what that means for how much weight to give it. Nothing here is medical advice. If you are pregnant, have a condition affecting your metabolism, or are planning a large change in intake, speak to a doctor or a registered dietitian first.
Frequently asked questions
What are macros?
Macros — macronutrients — are the three things food is built from that carry energy: protein, fat and carbohydrate. Protein and carbohydrate supply about 4 kcal per gram, fat about 9. Counting macros rather than only calories means you are deciding not just how much energy you eat, but what that energy is made of.
How does a macro calculator work?
In three steps. It estimates your maintenance calories from your body and activity level, shifts that number up or down for your goal, then splits the result into grams of protein, fat and carbohydrate. Every macro calculator is a calorie calculator with a division step on the end, which is why the calorie estimate underneath matters more than the split.
How do I calculate my macros by hand?
Start from your calorie target. Set protein at 1.6–2.2 g per kg of bodyweight and multiply by 4 to get its calories. Set fat at 20–30% of your target calories and divide by 9 for grams. Subtract both from your target and divide what is left by 4 — those are your carbohydrate grams. That is the whole calculation.
What is the best macro split?
There is no single best split, which is why this calculator does not print one. Protein has good evidence behind a target near 1.6–2.2 g per kg. Fat has a sensible floor for hormone and vitamin reasons. Beyond that, the ratio of fat to carbohydrate is largely a preference question, and the split you will actually stick to beats the theoretically optimal one.
How much protein should I eat?
Between 1.6 and 2.2 grams per kilogram of bodyweight covers almost everyone training with weights, with the upper half of that range being the sensible place to sit while in a deficit, when protein also helps protect lean mass. Going above roughly 2.2 g/kg has not been shown to add anything for most people.
How much fat should I eat?
Twenty to thirty percent of your calorie target is the usual working range, and this calculator uses it. There is a floor worth respecting — fat is needed to absorb the fat-soluble vitamins and to support hormone production — so very low-fat targets are best avoided even when the calorie arithmetic would allow them.
How many carbs should I eat?
Whatever your calorie target has left after protein and fat are set. That sounds dismissive, but it is genuinely how the arithmetic works: carbohydrate is the flexible remainder. If you train hard, more carbohydrate in that remainder tends to help performance. If you prefer eating fewer, nothing breaks.
Why does this calculator show macro ranges instead of exact grams?
Because the calorie estimate underneath carries roughly a ±16% error, and dividing an uncertain number cannot produce a certain one. A calculator that tells you to eat 187 g of carbohydrate has hidden that error rather than removed it. The ranges shown here are the honest width of the answer, and any point inside one is a reasonable target.
Is this macro calculator free?
Yes, fully. No account, no email, no paywall, and no gated result — the macro split is on the same page as the calorie estimate, not behind a form. The calculation runs in your browser rather than on a server, so nothing you type is sent anywhere. There is no paid version for this to be a trial of.
What calorie deficit should I use to lose weight?
Ten to twenty-five percent below your maintenance calories, which works out at roughly 0.25–0.7% of bodyweight per week. Percentages beat flat rules like "500 calories a day" because that same deficit is gentle for a 120 kg person and severe for a 55 kg one. Larger deficits do not reliably produce faster fat loss, only faster lean-mass loss.
Should my macros change when cutting or bulking?
The calorie target changes a lot; the macro logic barely changes at all. Protein stays in the same 1.6–2.2 g/kg band and is worth biasing upward in a deficit. Fat stays a percentage of whatever the new calorie number is. Carbohydrate absorbs almost all of the difference, because it is the remainder in both directions.
Do I need to hit my macros exactly every day?
No. Weekly consistency matters far more than daily precision, and the estimate you are working from is not precise enough to justify chasing single grams. Landing inside your protein range most days and near your calorie target across the week is the part that does the work.
Is IIFYM the same as counting macros?
Broadly yes — IIFYM, "if it fits your macros", is the flexible-dieting name for hitting macro targets without restricting particular foods. The arithmetic is identical to what this page produces. The caveat is that macros say nothing about fibre or micronutrients, so an IIFYM target still needs real food behind it.
Are macros different for women?
The equations use sex as an input, so the calorie estimate already differs, and everything downstream follows from it. The macro rules themselves — protein per kilogram, fat as a percentage, carbohydrate as remainder — are not sex-specific. What does apply is the intake floor: below roughly 1,200 kcal, this calculator shows the floor rather than the number the percentage asked for.
Why do other macro calculators give me different numbers?
Almost always because they assumed a different activity multiplier or a different split convention, not because their formula is better. Change your activity bucket by one step and the calorie target moves 150–250 kcal, which moves every macro with it. That is why the arithmetic is shown here — so you can see which assumption you disagree with.