๐ Macro Nutrient Calculator
Enter your daily calorie target along with a protein/carb/fat (PFC) split percentage to calculate target intake in grams for each macronutrient. Includes "Balanced", "Low-Carb", and "High-Protein" presets to match your diet goals.
How to use
- Enter your total daily calorie target.
- Choose a preset or adjust the protein, carb, and fat percentage sliders yourself.
- Target grams for each macronutrient are calculated automatically.
How the calculation works
This tool splits a daily calorie target into protein, carbohydrate and fat by percentage and calculates how many grams of each that means. Protein (g) = calories ร protein % รท 4 Carbohydrate (g) = calories ร carbohydrate % รท 4 Fat (g) = calories ร fat % รท 9 The 4 and 9 are the Atwater factors: protein and carbohydrate provide about 4 kcal per gram, fat about 9 kcal. You can set the percentages freely with the sliders or pick a preset: balanced (30/40/30), low-carb (40/20/40) or high-protein (40/40/20). A warning appears if the three percentages do not add up to 100%.
Worked example
2,000 kcal a day, 30% protein, 40% carbohydrate, 30% fat Protein: 2,000 ร 0.30 รท 4 = 150 g Carbohydrate: 2,000 ร 0.40 รท 4 = 200 g Fat: 2,000 ร 0.30 รท 9 โ 66.7 g For reference, Japan's Dietary Reference Intakes (2025) target 13โ20% protein, 20โ30% fat and 50โ65% carbohydrate for adults aged 18โ49.
Things to be aware of
- For people doing strength training, protein is often set at about 1.6โ2.2 g per kg of body weight, rather than as a percentage.
- People with kidney disease may need to restrict protein. If you have been given dietary restrictions, follow your doctor or dietitian.
- Use a BMR or daily calorie calculator to set your calorie target.
FAQ
How are the gram amounts calculated?
Protein and carbs are counted at 4 kcal per gram, and fat at 9 kcal per gram. Grams = total calories ร percentage รท kcal-per-gram for that macro.
What happens if the percentages don't add up to 100%?
A warning is shown, but the calculation still proceeds using the calorie value implied by each percentage. Adjust the three sliders so they sum to 100% for accurate totals.
I'm not sure which macro split is right for me
A "Balanced" split (roughly 30/40/30 protein/carbs/fat) is broadly recommended, but the ideal ratio depends on your goals (weight loss, muscle gain, athletic training, etc.). Consider consulting a nutritionist or healthcare provider.