Crunch Macro Calculator
Calories set the budget; macros decide what the budget buys. Enter a daily calorie target — or build one from your stats — then pick a split and get exact grams of protein, carbs and fat to aim at.
How it works
In TDEE mode, BMR comes from the Mifflin–St Jeor equation (men: 10 × kg + 6.25 × cm − 5 × age + 5; women the same with −161), multiplied by your activity factor, then adjusted by your goal. The split then divides the calories: each macro’s share ÷ 4 kcal/g for protein and carbs, ÷ 9 kcal/g for fat. Note the percentages are of calories, not grams — 30% fat by calories is far fewer grams than 30% protein.
Formula & worked example
Formula: Grams = calories × split % ÷ energy density: protein and carbs carry 4 kcal per gram, fat 9 kcal per gram. In TDEE mode the calorie target comes from the Mifflin–St Jeor BMR — men: 10 × kg + 6.25 × cm − 5 × age + 5; women: the same with −161 — multiplied by the activity factor and adjusted by the goal.
Worked example: At 2,000 kcal, the balanced split (30/40/30) gives 150 g protein, 200 g carbs and 66.7 g fat; high-protein (40/30/30) gives 200/150/66.7; low-carb (35/20/45) 175/100/100; keto (20/5/75) 100/25/166.7. A 30-year-old man at 80 kg and 178 cm has a BMR of 1,767.5 kcal, a TDEE of about 2,740 at moderate activity.
Frequently asked questions
What are my macros at 2,000 calories on a balanced split?
Balanced (30/40/30): 150 g protein, 200 g carbs, 66.7 g fat. High-protein (40/30/30) moves it to 200 g protein and 150 g carbs; keto (20/5/75) drops carbs to 25 g and pushes fat to 166.7 g. Same calories, very different plates.
How much protein do I actually need?
General guidance clusters around 1.6–2.2 g per kg of body weight for people training to build or keep muscle, and 0.8 g/kg as the sedentary floor. On the high-protein split at 2,000 kcal you get 200 g — enough for most lifters up to about 100 kg.
Should I use the calorie number or build my TDEE?
If you already track and know your maintenance calories, enter the number — real data beats any formula. If you are starting cold, the TDEE build is the honest estimate: a 30-year-old man, 80 kg, 178 cm, moderately active, lands at about 2,740 kcal.
Why do the grams not add back to exactly my calories?
Rounding. Each gram figure is rounded to a tenth, so the check sum can drift by a few kcal — under 0.5% either way. Real food labels round far more aggressively than this.
📏 What is the fat percentage today?
The Body Fat Calculator uses the Navy tape method to split your weight into fat mass and lean mass — the baseline macros then work from.