Macro Calculator: Protein, Carbs and Fat per Day
Our macro calculator turns your daily calories into grams of protein, carbs and fat. It estimates your calories with the Mifflin St Jeor equation, then splits them by the diet you choose. You can also type in your own calorie target and see the grams for every meal.
What Are Macros?
Macros, short for macronutrients, are the three nutrients that supply almost all of your calories. Protein and carbohydrates give 4 calories per gram, while fat gives 9. Alcohol adds 7 calories per gram but is not counted as a macro you need.
Each one has a different job. Protein builds and repairs muscle and other tissue. Carbs are the main fuel for your brain and for hard exercise, and fat supports hormones and helps you absorb vitamins A, D, E and K.
Counting calories tells you how much you eat. A macro calculator tells you what those calories are made of, which matters for muscle, energy and how full you feel. That is why a macronutrient calculator starts with your calories before it splits them.
How to Use the Macro Calculator
- Choose US or metric units and enter your sex, age, weight and height.
- Pick the activity level that matches a normal week, not your best week.
- Choose a goal to lose, keep or gain weight.
- Select a diet split or choose Custom and enter your own percentages.
- Set how many meals you eat per day.
The macronutrient calculator results show your daily calories and the grams of protein, carbs and fat. Each macro is also split by meal, and you see your protein per pound and per kilogram of body weight. If you already know your calorie target, type it in and the tool skips the estimate.
How the Macronutrient Calculator Works
First the tool finds your basal metabolic rate, which is the energy you burn at rest. It uses the Mifflin St Jeor equation, which research has found to be among the most accurate for healthy adults. For men it is 10 × weight in kg + 6.25 × height in cm − 5 × age + 5, and women use −161 at the end.
Next it multiplies that number by an activity factor to get your total daily energy use. The goal then adds or removes calories. A gap of about 500 calories a day is the classic rule of thumb for one pound of change per week.
| Activity level | Factor |
| Little or no exercise | 1.2 |
| Light, 1 to 3 workouts a week | 1.375 |
| Moderate, 3 to 5 workouts a week | 1.55 |
| Very active, 6 or 7 workouts a week | 1.725 |
| Athlete or physical job | 1.9 |
Finally the macronutrient calculator splits the calories by your chosen percentages. Protein and carb grams equal their calories divided by 4, and fat grams equal its calories divided by 9. Rounding to whole grams can make the totals differ by a few calories.
Macro Splits Compared
The balanced and low fat splits sit inside the ranges the US National Academies suggest for adults. The high protein, low carb and keto splits go below the suggested 45% for carbs. The grams below are for 2,760 calories a day.
| Diet | Protein / Carbs / Fat | Grams per day |
| Balanced | 25% / 50% / 25% | 172 g / 345 g / 77 g |
| High protein | 35% / 35% / 30% | 241 g / 241 g / 92 g |
| Low carb | 35% / 25% / 40% | 241 g / 172 g / 123 g |
| Keto | 20% / 5% / 75% | 138 g / 34 g / 230 g |
| Low fat | 25% / 55% / 20% | 172 g / 379 g / 61 g |
There is no single best split. The right one is the split you can follow for months, which depends on the foods you like and how you train. Many people start the macro calculator on the balanced plan and adjust from there.
Macro Calculator Examples
Keeping Your Weight
A 30 year old man weighs 176 lb, stands 5 ft 11 in and works out three to five times a week. The macro calculator gives a BMR of 1,780 and a daily need of 2,760 calories. On the balanced split, that is 172 g of protein, 345 g of carbs and 77 g of fat, or about 57 g of protein per meal across three meals.
Losing Fat on High Protein
The same man picks a goal of one pound a week and the high protein split. The macronutrient calculator drops his target to 2,260 calories with 198 g of protein, 198 g of carbs and 75 g of fat. Extra protein helps protect muscle while he eats less.
A Smaller Body and Lighter Training
A 35 year old woman at 150 lb and 5 ft 5 in trains one to three times a week. Her daily need is 1,892 calories, which the balanced split turns into 118 g of protein, 237 g of carbs and 53 g of fat. To lose a pound a week on high protein, the macronutrient calculator shows 1,392 calories with 122 g of protein, 122 g of carbs and 46 g of fat.
How Much Protein Do You Need?
The basic recommended amount for adults is 0.8 g of protein per kilogram of body weight. That figure covers the needs of inactive people, not those who lift weights or diet hard. Sports nutrition groups suggest roughly 1.4 to 2.0 g per kilogram for active people.
Our macronutrient calculator shows your protein per kilogram and per pound under the results, so it doubles as a protein calculator. The high protein and low carb splits can reach 2.5 to 3 g per kilogram for people who eat a lot. That is generally considered safe for healthy adults, but people with kidney disease should check with a doctor first.
Spread your protein across the day. Three to five meals with 25 to 40 g each works well for most people. A protein calculator can only set the target, so plan the meals that will hit it.
Setting Macros for Weight Loss
Calories decide whether you lose weight, and macros decide what that weight is made of. Keep protein high so most of the loss comes from fat instead of muscle. Then fill the rest of your calories with the carbs and fats you enjoy most.
Aim to lose about 0.5 to 1% of your body weight per week. Faster loss tends to cost muscle and energy, and it is harder to keep up. The macronutrient calculator warns you when the target falls below 1,200 calories for women or 1,500 for men.
Recheck your targets every 10 to 15 pounds you lose. A lighter body burns fewer calories, so the old numbers stop working after a while. Run the macronutrient calculator again with your new weight.
How to Count Macros
Tracking matters as much as the targets. The macro calculator gives you the numbers, and these habits help you hit them. Most of them take only a minute a day.
- Weigh food raw with a kitchen scale.
- Read the grams on nutrition labels and log them in an app.
- Prepare repeat meals so you can copy them from day to day.
- Count cooking oils and sauces, which hide a lot of fat.
You do not need to hit every number to the gram. Staying within about 5 to 10 grams of each target is close enough for steady results. Use the macro calculator again whenever your training or goal changes.
Who Should Get Professional Advice
These numbers are estimates for healthy adults. Children, teens, pregnant or breastfeeding women and people with diabetes or kidney problems have different needs. A macronutrient calculator cannot account for medical conditions or medicines. Speak to a doctor or registered dietitian before you change your diet in those cases.
Why Use Our Macro Calculator
It estimates your calories, offers five diet splits plus a custom option and shows grams per meal and protein per pound. Every result explains the formula behind it, so you can check each step. Enter your details and get your macros now.
Frequently asked questions
Is this macro calculator free?
Yes, it is free with no sign up and runs in your browser.
What is the best macro split for fat loss?
Many people do well on a higher protein split, such as 35% protein, 35% carbs and 30% fat.
How many calories are in a gram of each macro?
Protein and carbs have 4 calories per gram, and fat has 9.
How to count macros without an app?
Weigh your food, read the labels and add up the grams in a notebook.
Can I use the macronutrient calculator for keto?
Yes, pick the keto split of 20% protein, 5% carbs and 75% fat.
How often should I update my macros for weight loss?
Update them after every 10 to 15 pounds of weight change.
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