Keto Macros 101: How to Calculate Your Fat, Protein and Carbs
Updated: July 18, 2026 — By the Supplement24Hours editorial team
Keto works by flipping your fuel source from glucose to fat — but only if the macros are right. This guide gives you the exact numbers and a free calculator, then covers the two supplements that make the first weeks easier.
The standard keto split
A classic ketogenic ratio draws roughly 70% of calories from fat, 25% from protein and 5% from carbohydrate — in practice, 20–30 g of net carbs per day for most adults. Net carbs are total carbs minus fiber, which is why leafy vegetables stay on the menu while bread leaves it.
Calculate your numbers
Your targets depend on body size, activity and goal. Our free keto macro calculator applies the Mifflin-St Jeor equation to estimate your calorie needs, then converts them into daily grams of fat, protein and net carbs. It takes about twenty seconds — bookmark your result.
Why protein is a range, not a limit
Early keto advice feared protein would break ketosis. Current practice sets protein at 0.6–1.0 g per pound of lean mass: enough to preserve muscle, not enough to meaningfully disrupt ketone production. When in doubt, err higher on training days.
Surviving the keto flu
The headache-fatigue-cramps phase of week one is mostly an electrolyte problem: insulin drops, the kidneys excrete sodium, and potassium and magnesium follow. Two products address this directly. A dosed keto electrolyte complex replaces sodium, potassium and magnesium in capsule form, and MCT oil powder supplies C8/C10 fats the liver converts to ketones quickly — useful energy while your metabolism adapts. Browse the full Keto Diet collection for current prices.
A sample day at 1,800 kcal
| Macro | Share | Grams |
|---|---|---|
| Fat | 70% | 140 g |
| Protein | 25% | 113 g |
| Net carbs | 5% | 23 g |
FAQ
How do I know I'm in ketosis?
Urine strips work in the first weeks; blood ketone meters are the accurate option later. Readings of 0.5–3.0 mmol/L indicate nutritional ketosis. Appetite reduction and steady energy are the everyday signs.
Do I need exogenous ketones?
They are optional. BHB salts can soften the adaptation window and fuel workouts, but they do not replace getting your macros right — treat them as a bridge, not a shortcut.
Is keto safe for everyone?
People with diabetes on medication, kidney or liver conditions, or who are pregnant should only attempt carbohydrate restriction under medical supervision. This guide is educational, not medical advice.
