Strict Keto Macro Calculator (20 g Net Carbs)

Strict keto — also called therapeutic or classical keto — caps net carbs at 20 g per day, which is the threshold most reliably associated with measurable blood ketones (≥0.5 mmol/L) across the widest range of individuals. At 20 g net carbs, the liver rapidly depletes liver glycogen and ramps up ketone production, typically within 24–48 hours for most people. The protein and fat targets matter on strict keto because going too high on protein can raise glucagon and suppress ketone levels through gluconeogenesis. The 1.6 g/kg protein recommendation used in this calculator sits below the gluconeogenesis threshold for most people while still being high enough to preserve muscle. Fat should make up the majority of your remaining calories — roughly 60–70 % — which is why the per-meal fat number often surprises new keto dieters. Foods that fit easily under 20 g net carbs per day include leafy greens, above-ground vegetables, eggs, meat, fish, cheese, and nuts in moderation. Hidden carbs in sauces, condiments, and processed keto products are the most common reason people unknowingly exceed the limit.