Macro Calculator

Take a 30-year-old man who is 5'10" (178 cm), weighs 185 lb (84 kg) and trains 3-5 days a week. His maintenance calories (TDEE) come to about 2,800 per day. On a balanced 30 / 40 / 30 split, that becomes roughly 210 g protein, 280 g carbs and 93 g fat. Switch his goal to cutting (-20%) and the target drops to about 2,240 calories, automatically rebalancing his macros. That is what a macro calculator does: it turns a calorie number into the three numbers you actually track each day.

How macros are calculated

Two steps. First we set your daily calories from your TDEE and goal. Then we split those calories into grams of each macronutrient, using the standard energy values:

Protein and carbohydrate each provide 4 calories per gram, and fat provides 9 calories per gram. The high-protein plan instead anchors protein to your body weight (about 0.9 g per pound), sets fat at 25% of calories, and fills the rest with carbs - the way most lifters set up their macros.

Calories come first, then macros

For weight change, your total calories decide the direction - a deficit loses fat, a surplus gains weight, maintenance holds steady. Macros decide the quality of that change. Adequate protein protects muscle in a cut and supports growth in a bulk, fat keeps hormones and satiety healthy, and carbs fuel training and recovery. That is why the calculator locks calories to your goal first, then divides them. If you only want that headline calorie number on its own, the Calorie Calculator and the TDEE Calculator give you the same maintenance figure this tool starts from.

Protein, carbs and fat: what each does

• Protein builds and repairs muscle and is the most filling macro. Aim for roughly 0.7-1.0 g per pound of body weight if you train - the dedicated Protein Calculator dials this in on its own.
• Fat supports hormones, vitamin absorption and satiety. Keep it at a minimum of about 0.3 g per pound (around 20-30% of calories).
• Carbs are your main training fuel. After protein and fat are set, the remaining calories usually go to carbs.

Balanced vs high-protein (IIFYM)

The balanced 30/40/30 split is easy to follow and works well for general health and moderate goals. The high-protein plan is better if your priority is keeping or building muscle, especially while cutting, because it ties protein to your actual body weight rather than a flat percentage. Both follow the IIFYM (if it fits your macros) idea: any foods are fine as long as the daily totals add up - though most of your calories should still come from whole, nutrient-dense foods.

Make your macros more accurate

No formula knows your exact metabolism, so treat the output as a starting point. Hit your targets consistently for 2-3 weeks, weigh yourself a few times a week and average the readings. If you are not progressing as expected, adjust calories by 100-200 and recalculate. Re-run the numbers after every 10-15 lb (5-7 kg) of weight change, since a lighter or heavier body has different needs.

How to use this macro calculator

You only need a few numbers to get a realistic daily target. Work through the fields in order:

1. Units: choose imperial (lb/ft-in) or metric (kg/cm). Every other field follows that choice.
2. Age, sex, height and weight: these feed the Mifflin-St Jeor equation that estimates your BMR (the calories your body burns at rest).
3. Activity level: pick the option that matches a typical week, from sedentary (desk job, little exercise) to very active (hard training or a physical job). This multiplies your BMR into your TDEE.
4. Goal: choose cutting (lose fat), maintaining, or bulking (gain weight). Cutting trims 20% off your TDEE, maintaining keeps it, and bulking adds 15%.
5. Macro plan: pick the balanced 30/40/30 split or the high-protein plan. The high-protein plan anchors protein to your body weight first, then divides the rest.

The result updates instantly. Read your daily calorie target at the top, then use the grams of protein, carbs and fat as your tracking goals for the day - that is what you log in a food app or build your meals around.

Who this calculator is for

This tool is built for anyone who wants to turn a vague "eat better" goal into concrete daily numbers. That includes:

• People losing fat who want to keep protein high so the weight they lose is fat, not muscle.
• Lifters and athletes setting up a bulk or cut and needing a protein target tied to their body weight.
• Flexible dieters (IIFYM) who track macros in an app and just need accurate starting targets.
• Beginners who have heard "hit your macros" but never had real numbers to aim at.
• Anyone maintaining weight who wants a balanced split that keeps energy and recovery steady.

A second worked example: a woman cutting on a high-protein plan

Consider a 35-year-old woman who is 5'5" (165 cm), weighs 150 lb (68 kg) and is moderately active. Her maintenance calories come to roughly 2,130 per day. She picks cutting, which trims 20% down to about 1,705 calories. On the high-protein plan, protein is anchored to her body weight at about 0.9 g/lb, which is roughly 135 g protein (540 calories). Fat is set near 25% of calories, about 47 g fat (427 calories), and the remaining 740 calories become carbs, about 185 g. Keeping protein high while calories are low is exactly what protects her muscle during the cut - the same calorie deficit with low protein would cost her more lean mass.

Key terms explained

• BMR (basal metabolic rate): the calories your body burns at complete rest to keep you alive. The calculator estimates it with the Mifflin-St Jeor equation.
• TDEE (total daily energy expenditure): your BMR multiplied by an activity factor - the calories you burn on a normal day. This is your maintenance level.
• Calorie deficit / surplus: eating below your TDEE (deficit) drives fat loss; eating above it (surplus) drives weight gain. Macros divide those calories; they do not set the direction.
• Macronutrient: protein, carbohydrate or fat - the three nutrients that supply energy. Protein and carbs give 4 cal/g, fat gives 9 cal/g.
• IIFYM: "if it fits your macros," a flexible-dieting approach where any food is allowed as long as your daily protein, carb and fat totals are met.
• Lean mass: everything in your body that is not fat - muscle, bone, organs and water. Adequate protein and resistance training protect it while you diet.

What changes the result the most

If you adjust the inputs and watch the numbers move, a few factors dominate:

• Goal: the single biggest lever - cutting vs. bulking swings your calorie target by 35% or more.
• Activity level: the jump from sedentary to very active can change your TDEE by 600-800 calories.
• Body weight: heavier bodies burn more at rest and need more protein, so weight moves both calories and protein grams.
• Macro plan: the high-protein plan raises protein and lowers carbs versus the balanced 30/40/30 split, at the same calorie total.
• Sex and age: these shift BMR modestly - men and younger people generally have a higher baseline burn.

Turning daily macros into meals

A daily target like 210 g protein, 280 g carbs and 93 g fat is easy to hit once you stop thinking in pure numbers and start thinking in building blocks. A practical approach is to anchor each meal around a protein source, then add carbs and fat to taste. Spreading protein across three or four meals of roughly 30-50 g each is slightly better for muscle protein synthesis than loading it all into one meal, though the daily total still matters most. Some easy reference points: a palm-sized portion of cooked chicken, fish or lean beef is about 25-30 g of protein; a cup of cooked rice or oats is roughly 45 g of carbs; a tablespoon of oil or nut butter is about 14 g of fat. You do not have to weigh everything forever - after a couple of weeks you will recognise these portions by eye and only need the scale for new or calorie-dense foods.

Carbohydrate timing is the one place where when you eat can help a little: putting a larger share of your carbs around training tends to improve workout energy and recovery. It is a minor optimisation, though. If a high-carb breakfast suits your routine better than a pre-workout one, the difference in results is small as long as your daily protein and total calories are on target.

When and how to adjust your macros

Your first calculation is a hypothesis, not a verdict. Bodies adapt: as you lose fat your maintenance calories fall, and as you gain muscle they rise, so the numbers that worked in week one will eventually stop producing the same result. The fix is to track the trend, not the day. Weigh yourself most mornings under the same conditions and watch the weekly average rather than any single reading, which can swing two or three pounds on water and food in your gut alone.

If you are cutting and the weekly average has not moved for two to three weeks, drop calories by about 100-200 - take it from carbs or fat and leave protein where it is, then recalculate the split. If you are bulking and gaining faster than roughly 0.25-0.5% of body weight per week, you are likely adding more fat than muscle; trim the surplus the same way. When your body weight changes by 10-15 lb (5-7 kg) in either direction, re-run this macro calculator from scratch, because a meaningfully lighter or heavier body has a different BMR, TDEE and protein requirement. Treating macros as a dial you nudge over time, rather than a fixed prescription, is what separates people who keep progressing from those who stall.

How it compares to related calculators

This page answers "what should my daily protein, carbs and fat be?" If your question is different, a sister tool fits better:

• To find just your daily calorie number, use the Calorie Calculator.
• To see your maintenance burn on its own, use the TDEE Calculator.
• To set only a protein target, use the Protein Calculator.
• To plan how big a deficit you need to hit a goal weight by a date, use the Calorie Deficit Calculator.
• To check the resting burn that sits underneath your TDEE, use the BMR Calculator.
• To estimate body composition rather than just weight, use the Body Fat Calculator.

Sources

• National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) - Weight Management.
• U.S. Department of Agriculture & HHS - Dietary Guidelines for Americans (Acceptable Macronutrient Distribution Ranges).
• National Institutes of Health (NIH) - protein and energy needs.
• U.S. Food & Drug Administration (FDA) - Nutrition Facts Label (4/4/9 calories-per-gram values).