Keto Macros (Grams) Calculator
Set ketogenic macros in grams — carbs capped, protein from body weight, and fat filling the rest of your calorie budget.
How it works
Protein g = weight × g/kg · Fat g = (calories − carb g×4 − protein g×4) ÷ 9 · (carbs 4, protein 4, fat 9 kcal/g)
A ketogenic diet fixes carbohydrates low — typically 20–50 g of net carbs — and sets protein from body weight to protect muscle, then lets dietary fat fill whatever calories remain. Because fat carries 9 kcal per gram versus 4 for protein and carbs, fat ends up supplying about 65–75% of calories. This tool works out the grams of each macro from your calorie target, body weight, carb cap and protein goal.
Worked example
On 2,000 kcal at 75 kg: protein = 75 × 1.6 = 120 g (480 kcal), net carbs 25 g (100 kcal). Fat fills the rest: (2,000 − 480 − 100) ÷ 9 = 1,420 ÷ 9 ≈ 158 g of fat — about 71% of calories.
Frequently asked questions
How many carbs are allowed on keto?
Most people reach and stay in ketosis on 20–50 g of net carbs per day, with 20–30 g being a common starting point. Net carbs are total carbohydrate minus fibre (and, for some, sugar alcohols).
Why is protein set from body weight?
Protein needs scale with lean mass, not calories, so 1.6–2.0 g per kg protects muscle while dieting. Setting protein too high is fine for muscle but leaves fewer calories for fat; too low risks muscle loss.
Why does fat fill the remaining calories?
On keto, carbs are capped and protein is fixed, so fat is the flexible macro that makes up your energy needs. That is why fat lands at roughly 70% of calories on a standard ketogenic diet.
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Educational estimate only — not medical, dietary or fitness advice. Individual needs vary; consult a qualified clinician or registered dietitian before making health decisions.