Smart Calculator Pro

Smart Calculator Pro

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Macro Calculator

Calculate your ideal daily intake of protein, carbohydrates, and fat based on your calorie target and fitness goal. Adjust macro ratios to match any diet plan from low-carb to high-protein.

Your total daily calorie target. Use a TDEE or calorie calculator if you are unsure.

Your primary fitness goal determines suggested macro ratios.

Percentage of total calories from protein. Each gram of protein provides 4 calories.

Percentage of total calories from carbohydrates. Each gram of carbs provides 4 calories.

Percentage of total calories from fat. Each gram of fat provides 9 calories.

This macro calculator converts your daily calorie target into specific gram amounts for each macronutrient. Choose from preset ratios for weight loss, maintenance, or muscle gain, or enter custom percentages to match any diet approach including IIFYM (If It Fits Your Macros), keto, zone, and more.

How It Works

Macro Calculation

Grams = (Calories x Ratio%) / Calories per Gram

Each macronutrient's grams equal your total calories multiplied by its percentage, divided by the calories per gram for that nutrient.

Protein grams = (Total Calories x Protein%) / 4, because protein provides 4 calories per gram

Carb grams = (Total Calories x Carb%) / 4, because carbohydrates provide 4 calories per gram

Fat grams = (Total Calories x Fat%) / 9, because fat provides 9 calories per gram

All three macro percentages should add up to 100%

Important Notes:

  • •This calculator uses standard Atwater factors: 4 cal/g for protein, 4 cal/g for carbs, 9 cal/g for fat
  • •Preset ratios are general recommendations; individual needs vary based on body composition, training, and health conditions
  • •The IIFYM approach allows flexible food choices as long as daily macro targets are met

Worked Example

A person eating 2,000 calories per day for weight maintenance with a 30/40/30 protein/carb/fat split.

Inputs:

  • calories:2,000
  • goal:maintain
  • protein Ratio:30
  • carb Ratio:40
  • fat Ratio:30

Result:

With 2,000 calories and a 30/40/30 split: 150 g protein (600 cal), 200 g carbs (800 cal), and 67 g fat (600 cal).

Who Is This Calculator For?

  • people tracking macros
  • IIFYM dieters
  • bodybuilders and athletes
  • anyone planning a balanced diet

Frequently Asked Questions

Macros, short for macronutrients, are the three main nutrients your body needs in large amounts: protein, carbohydrates, and fat. Each provides energy measured in calories and serves distinct roles in muscle repair, energy production, and hormone regulation.
IIFYM stands for If It Fits Your Macros. It is a flexible dieting approach where you can eat any foods you want as long as you hit your daily protein, carb, and fat targets. The idea is that macro balance matters more than individual food choices for body composition.
The general recommendation is 0.36 g per pound for sedentary adults. For active individuals aiming to build or preserve muscle, 0.7 to 1.0 g per pound is widely recommended. Competitive athletes or those in a calorie deficit may benefit from up to 1.2 g per pound.
A common weight-loss split is 40% protein, 30% carbs, and 30% fat. Higher protein helps preserve muscle during a calorie deficit and keeps you feeling full longer. However, the best ratio depends on your activity level, preferences, and how your body responds.
No. Aiming within 5 to 10 grams of each target is close enough for most people. Consistency over the week matters more than perfection on any single day. Focus on hitting your protein target first, then fill in carbs and fat around it.
Some people adjust macros by eating slightly more carbs on training days for energy and reducing them on rest days. This is called carb cycling. It is optional and most people see good results with consistent daily targets.

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Last updated: April 20, 2026