Keto Calculator
A ketogenic split with carbohydrate capped in grams, not percentages.
Your targets
Daily macros
Why carbs are capped in grams
Most macro calculators split calories by percentage. A ketogenic diet cannot work that way, becauseketosis depends on the absolute carbohydrate figure, not its share of intake. Twenty grams is twenty grams whether you eat 1,600 calories or 3,000 — expressing it as "5% of calories" would let the actual amount drift well past the threshold on a high-calorie day.
Protein is set from bodyweight for a related reason. Too little costs lean mass in a deficit; far too much can, through gluconeogenesis, work against ketosis in some people, though this is frequently overstated. Around 1.6 g per kilogram is a reasonable default for someone training. Fat then takes whatever calories remain — it is the balancing item rather than a target in its own right, which is why the fat figure moves whenever anything else does.
Two practical points. Net carbs — total minus fibre, and minus sugar alcohols under some conventions — is what most keto guidance counts, and fibre intake should stay high despite the restriction. And the first week or two commonly brings fatigue, headache and cramps, largely from water and electrolyte loss as glycogen depletes; sodium, potassium and magnesium intake matter more on keto than on most diets.
Medical disclaimer. This calculator is for general information and education only. It is not medical advice, not a diagnosis, and not a substitute for professional care. Ketogenic diets are a medical intervention in some contexts and are not suitable with type 1 diabetes, pancreatitis, liver disease, or certain metabolic disorders. They require supervision alongside insulin or glucose-lowering medication.Speak to a doctor or a registered dietitian before making significant dietary changes.Last reviewed .
Frequently asked questions
How many carbs can I eat on keto?
Most guidance puts the threshold at 20-50 g of net carbohydrate a day, with 20-25 g the usual starting point for reaching ketosis reliably. Tolerance varies — some people maintain ketosis at 50 g, others need to stay nearer 20.
Why is protein set from bodyweight rather than as a percentage?
Because protein requirements track lean mass, not calorie intake. Setting it as a percentage means eating less protein on a cut, which is exactly when protein matters most for preserving muscle.
Does too much protein break ketosis?
It can in principle, through gluconeogenesis, but the effect is commonly overstated. Gluconeogenesis is demand-driven rather than simply supply-driven, and moderate protein around 1.6 g/kg does not prevent ketosis for most people.
What are net carbs?
Total carbohydrate minus fibre, and under some conventions minus sugar alcohols. Fibre is not absorbed and does not raise blood glucose, so it is generally excluded. Most keto targets refer to net rather than total carbohydrate.
What is keto flu?
Fatigue, headache, irritability and cramps in the first week or two, largely caused by water and electrolyte loss as glycogen depletes. Increasing sodium, potassium and magnesium usually reduces it considerably.