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Macro Calculator
Daily protein, carbs and fat in grams for your goal – lose, maintain or gain – and diet style, per day and per meal.
Calculated in your browser – nothing you enter is sent or stored.
Macros – protein, carbohydrates and fat – are where all your calories come from. This macro calculator turns your daily calorie needs into grams of each macro for your goal (lose weight, maintain or build muscle) and diet style (balanced, high protein, low carb or keto), per day and per meal.
How to Use the Macro Calculator
- Enter your age, sex, height, weight and activity level. The calculator estimates your maintenance calories with the Mifflin-St Jeor equation.
- Choose a goal: a 250–500 calorie deficit to lose fat, maintenance, or a 250–500 calorie surplus to gain.
- Choose a diet style, or set your own percentages with Custom.
- Pick how many meals you eat to see grams per meal.
How Macros Are Calculated
Each gram of protein and carbohydrate has 4 calories; each gram of fat has 9. So:
- Protein grams = calories × protein % ÷ 4
- Carb grams = calories × carb % ÷ 4
- Fat grams = calories × fat % ÷ 9
Example: a 30-year-old man, 5 ft 9 in, 170 lb and moderately active needs about 2,668 calories a day to maintain his weight. On a balanced 30/40/30 split that is 200 g protein, 267 g carbs and 89 g fat – about 67 g of protein per meal over three meals.
| 2,668 calories | Protein | Carbs | Fat |
|---|---|---|---|
| Balanced (30/40/30) | 200 g | 267 g | 89 g |
| High protein (40/30/30) | 267 g | 200 g | 89 g |
| Low carb (40/20/40) | 267 g | 133 g | 119 g |
| Keto (25/5/70) | 167 g | 33 g | 208 g |
How Much Protein Do You Need?
The U.S. RDA is 0.8 g of protein per kg of body weight (0.36 g per lb) – the minimum to avoid deficiency. People who lift weights or are losing weight often benefit from 1.6–2.2 g per kg (about 0.7–1 g per lb) to keep and build muscle. If a percentage split gives you much more than that, you can move some of the protein calories to carbs or fat.
Recommended Ranges
The Dietary Guidelines for Americans suggest adults get 10%–35% of calories from protein, 45%–65% from carbohydrates and 20%–35% from fat. Low-carb and keto diets fall outside these ranges; they can work for weight loss, but talk to your doctor first if you have diabetes, kidney disease or take medication.
Tips for Hitting Your Macros
- Build each meal around a protein source – chicken, fish, eggs, Greek yogurt, tofu or beans.
- Choose fiber-rich carbs such as oats, potatoes, rice, fruit and vegetables.
- Measure oils, nut butters and dressings – fat adds calories fastest.
- Aim to be within about 5–10 g of each target; consistency over weeks matters more than perfection.
Not sure about your calorie target? Start with the TDEE calculator or the calorie deficit calculator.
Sources
- Dietary Guidelines for Americans 2020–2025 – Acceptable macronutrient distribution ranges
- National Academies – Dietary Reference Intakes for energy and macronutrients
- International Society of Sports Nutrition – Position stand: protein and exercise (2017)
Last reviewed: October 2026 by the ShrinkBee team. Macro targets are general estimates for healthy adults and are not medical or dietary advice.
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