Keto Calculator

A ketogenic diet cuts carbohydrate so low that the body switches to burning fat for fuel. This calculator turns your calorie target into keto macros. It is a serious diet change — read the checks at the top before you start.

Check before you start keto

  • On diabetes medicine — especially insulin, or tablets whose names end in -gliflozin (SGLT2 inhibitors)? Talk to your doctor first: doses often need changing, and very-low-carb eating can add to these tablets' risk of ketoacidosis.
  • Pregnant or breastfeeding, have kidney disease, or have had an eating disorder? Don't start keto without medical supervision.

Don't know your calories? Use the Calorie Calculator.

Net carbs

g

% of calories

Protein

g

% of calories

Fat

g

% of calories

Carbs fixed at your limit (ADA 2019: 20–50 g a day for ketosis) · protein = weight × g/kg · fat = remaining calories ÷ 9.

These calories don't cover your carbs and protein. Raise your calorie target — very low intakes need medical supervision.

Your results are attached to the form below

These figures are estimates for general awareness only and are not medical advice or a diagnosis. Read our Medical Disclaimer.

Want a Plan Built Around Your Numbers?

A certified dietitian will turn these figures into a diet that fits your routine and your food.

We respect your privacy. Your details are never shared.

How this is calculated

Carbohydrate is fixed at your chosen limit: the ADA's 2019 consensus report on nutrition therapy describes very-low-carbohydrate eating as often aiming for 20–50 g of non-fibre carbohydrate a day to reach ketosis. Protein = your weight × the g/kg you choose, starting from ICMR-NIN's 0.83 g/kg minimum. Fat = the calories left over ÷ 9. Energy per gram uses the standard Atwater factors (4 / 4 / 9).

What the evidence says

A 2019 scientific statement from the US National Lipid Association reviewed the research on low-carbohydrate and ketogenic diets. It found them no better than other approaches for weight loss, though they may help with appetite control, lower triglycerides and reduce medication needs in type 2 diabetes. Effects on LDL cholesterol were mixed, with some studies showing a rise, and there is little data beyond two years.

Who should check first

If you take medicine for diabetes, talk to your doctor before starting — doses often need adjusting when carbohydrate drops sharply, and with SGLT2-inhibitor tablets a very-low-carb diet can add to the risk of ketoacidosis. We also advise medical supervision if you're pregnant or breastfeeding, have kidney disease, or have a history of eating disorders.

Related calculators

For a moderate approach, compare the Macro Calculator and IIFYM Calculator. To count the carbs in packaged foods, use the Net Carbs Calculator.