What is a macro calculator and how do I calculate my macros?

A macro calculator estimates your daily calorie needs and how many grams of protein, carbs, and fat you should eat based on your body data, activity level, and goal. To calculate your macros, it first finds your TDEE (total daily energy expenditure), applies a calorie surplus or deficit for your goal, then splits those calories into protein, carbohydrate, and fat grams. This makes it a high protein macro calculator for weight loss, cutting, bulking, and muscle gain.

What is the best macro ratio for weight loss?

A common starting point for weight loss is a 40/30/30 split (40% carbs, 30% protein, 30% fat), but a higher-protein ratio around 40% protein, 30% carbs, 30% fat often works better for fat loss because protein preserves muscle and has the highest thermic effect of food. The best macro ratio is the one you can stay consistent with inside your calorie deficit, which is why this 40/30/30 macro calculator lets you pick a diet preference.

How many grams of protein, carbs, and fat should I eat per day?

Your grams of protein per day, plus carb and fat grams, depend on your calories and goal. Each gram of protein and carbohydrate has about 4 calories and each gram of fat about 9 calories, so the calculator converts your calorie target and chosen ratio into exact daily grams. For fat loss, protein is set high first, then the remaining calories are divided between carbs and fat.

How much protein per pound or per kilogram should I eat?

For muscle gain and cutting, research supports roughly 0.7 to 1 gram of protein per pound of body weight (about 1.6 to 2.2 grams per kilogram), often calculated from lean body mass to maximize muscle protein synthesis. The high protein macro calculator uses your inputs to set protein in this range so you preserve or build muscle while losing fat.

What is IIFYM and flexible dieting?

IIFYM means "If It Fits Your Macros," a flexible dieting style where any food is fine as long as it fits your daily protein, carb, and fat targets. Instead of banned foods, you eat to a calorie number and a macro split. This tool is an IIFYM calculator: the targets it gives you are the budget you track against.

How do macros differ for cutting vs bulking?

Cutting means eating in a calorie deficit to lose fat, with protein kept high to preserve lean mass, so use this as your macro calculator for cutting. Bulking means eating in a calorie surplus to support muscle gain, with more carbs to fuel training. The macros for muscle gain use the same protein target but add calories instead of subtracting them, which is why the calculator lets you set your goal and approach.

What are TDEE and the thermic effect of food?

TDEE is your total daily energy expenditure: the calories you burn per day from your resting metabolism (BMR), activity, and digestion. The thermic effect of food is the energy used to digest meals, and protein has the highest thermic effect, which is one reason high-protein plans help with fat loss. The calculator estimates your TDEE first, then builds your calorie and macro targets from it.

How accurate is the DrinkDigits Macro Calculator?

The DrinkDigits Macro Calculator uses validated formulas such as the Mifflin-St Jeor equation and standard activity multipliers. The results are reliable estimates for general nutrition planning and should be fine-tuned based on real-world progress and consistency.

How often should I recalculate my macros?

Most people should recalculate their macros every 2 to 4 weeks, especially if body weight, activity level, or training intensity changes.

Does this macro calculator work for different diets?

Yes. The macro targets can be applied to a wide range of eating styles, including balanced, high-protein, lower-carb, ketogenic, plant-based, and Mediterranean diets.

What should I do after calculating my macros?

Use your macro targets to plan meals, track intake, and monitor progress over 2 to 3 weeks. Adjust portions slightly over time based on energy levels, hunger, performance, and results.

Free nutrition tool

Your daily macros, dialed in.

Your daily macros are the grams of protein, carbs, and fat that make up your calorie target. A common starting split is roughly 30% protein, 40% carbs, and 30% fat, with protein near 0.7 to 1 gram per pound of body weight, then adjusted for whether you are cutting, maintaining, or bulking. Enter your body data and goal below for exact gram targets in under a minute, no signup.

Start calculating

Mifflin-St Jeor formulaUSDA macro ratiosNo signup

Live previewSample

Daily target

2,358kcal

Protein177g (30%)

Fat79g (30%)

Carbs236g (40%)

Body composition

23.7

BMI

1,715

BMR

2,358

TDEE

Verified math

Basic information

Your body data drives the BMR calculation.

Gender

Average uses the midpoint of male and female formulas for non-binary users.

Units

Height

Weight (lbs)

Age (years)

Activity & goal

Pick the option that matches your real week, not your ideal one.

Activity level

Primary goal

Approach

Diet preference

Your results

Fill in your body data, activity, goal, and approach. Results show here.

Method

How the math works.

Three numbers drive everything: BMR, TDEE, and your calorie adjustment. Whether you want macros for weight loss, macros for cutting, or macros for bulking, the same engine runs underneath: it sets a calorie deficit for fat loss or a calorie surplus for muscle gain, then splits the result into protein, carb, and fat grams. The best macro ratio for weight loss usually leans high protein, so the calculator front-loads protein before dividing the rest.

Step

BMR (Mifflin-St Jeor)

Calories your body burns at rest. Validated equation for healthy adults.

Men: 10×kg + 6.25×cm - 5×age + 5
Women: 10×kg + 6.25×cm - 5×age - 161

Step

TDEE

BMR multiplied by your activity level. Sedentary 1.2 up to Extra active 1.9.

TDEE = BMR × activity multiplier

Step

Target calories

TDEE plus or minus 200 to 750 cal based on your goal and approach. Floored at 110% of BMR for safety.

Target = TDEE ± adjustment

Reference

Activity multipliers

Level	Description	×
Sedentary Little or no exercise, desk job	Little or no exercise, desk job	1.2
Lightly active Light exercise 1-3 days per week	Light exercise 1-3 days per week	1.375
Moderately active Moderate exercise 3-5 days per week	Moderate exercise 3-5 days per week	1.55
Very active Hard exercise 6-7 days per week	Hard exercise 6-7 days per week	1.725
Extra active Very hard exercise plus physical job	Very hard exercise plus physical job	1.9

Reference

Macro split by diet

Diet	Protein	Fat	Carbs
Standard	30%	30%	40%
High Protein	35%	25%	40%
Low Carb	30%	40%	30%
Ketogenic	20%	75%	5%
Plant-based	15%	30%	55%
Mediterranean	20%	35%	45%

Protein = 4 kcal/g · Carbs = 4 kcal/g · Fat = 9 kcal/g

Flexible dieting

This is also an IIFYM calculator.

IIFYM stands for "If It Fits Your Macros," the flexible dieting approach where no food is off-limits as long as it fits inside your daily protein, carb, and fat targets. Instead of banning entire food groups, you hit a calorie number and a macro split, then build your meals however you like. That makes it easier to stay consistent because your favorite foods can still earn a place in the plan.

The catch is that flexible dieting only works once you know your numbers. This is the IIFYM calculator that gives you those numbers: it turns your body data, activity level, and goal into the exact grams of protein per day, plus the carb and fat grams that "if it fits your macros" relies on. Pick the Standard preset for a classic 40/30/30 split, or another diet preference to shift the ratio toward macros for muscle gain. Plug in your details above and use the resulting macro targets as the budget you eat against each day.

Back to calculator

Sources & reading

Where the numbers come from.

Methodology

Data sources

Calculations use the Mifflin-St Jeor equation for BMR, standard physical activity multipliers, and macronutrient ratios consistent with the USDA Dietary Guidelines. Cutting, muscle-building, and athletic-performance goals apply a 1.6 g/kg protein floor. To learn how to calculate macros for fat loss, the method is simple: protein is set first (a high protein intake near 0.7 to 1 gram per pound, or roughly 1.6 to 2.2 grams per kilogram, scaled toward lean body mass to support muscle protein synthesis), because dietary protein also carries the highest thermic effect of food. Calories are floored at 110% of BMR for safety. Water targets use 30 ml/kg/day, fiber targets use 14 g per 1000 kcal (USDA).

01
Mifflin-St Jeor Equation
Am J Clin Nutr, 1990 (peer-reviewed BMR formula)
02
USDA Dietary Guidelines for Americans
2020-2025 macronutrient intake guidance
03
NIH ODS: Protein Fact Sheet
Evidence-based daily protein recommendations
04
ISSN Position Stand on Protein and Exercise
Peer-reviewed protein timing and dosing

Related guides

Long-form articles that go deeper on the math, the protein science, and the food pairings behind your numbers.

Editorial

Built by Hunzala Ashfaq, Founder

Updated May 14, 2026Verified against peer-reviewed research and brand nutrition data

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Calories + activity

TDEE Calculator

Total daily energy expenditure. Get the calorie number that feeds straight into your macro split.

Open TDEE Calculator