Keto Calculator

How do keto macros work?

A ketogenic diet keeps carbohydrate very low so your body shifts from burning glucose to burning fat and ketones for fuel, a state called ketosis. In macro terms that usually means about 70 to 75 percent of calories from fat, 20 to 25 percent from protein, and only around 5 percent from carbohydrate. This calculator fixes your carbs at the daily limit you set, keeps protein at a sensible moderate level to protect muscle, and lets fat make up the rest of your calories. The calorie base comes from the Mifflin-St Jeor equation (1990), documented on our methodology page.

Understanding net carbs

Net carbs estimate the carbohydrate that actually raises blood sugar. You take the total carbohydrate on a label, subtract fiber because it is not digested for energy, and subtract about half of any sugar alcohols such as erythritol, which are only partly absorbed. The mini-tool above does this for a single food. Counting net carbs rather than total carbs is what lets keto eaters enjoy high-fiber vegetables and nuts while staying under their limit.

How do you make keto sustainable?

In the first weeks your body sheds water and sodium as insulin falls, which can cause the tiredness some call keto flu. Drinking enough fluid and adding a little salt usually helps, and the water intake calculator can set your target. Keep protein adequate rather than very low, since it preserves muscle and keeps you full, and confirm your number with the protein calculator. To analyze a full keto recipe, the recipe calorie calculator breaks it down per serving, and the general macro calculator covers non-keto splits if you decide to adjust.

Who should not use keto?

Keto suits many people but is not right for everyone. Anyone with diabetes on medication, kidney or liver disease, or a history of disordered eating should check with a doctor before cutting carbohydrate this low, and pregnant or breastfeeding women need broader carbohydrate intake. If keto feels too restrictive, a moderate deficit from the calorie deficit calculator produces the same fat loss with more food flexibility.

Limitations of this calculator

This tool sets target macros and estimates net carbs from the numbers you enter; it cannot measure or verify that you are in ketosis, which only blood, breath, or urine testing can indicate. The calorie base is a predictive estimate within about 10 percent, and net carbs are an approximation, since sugar-alcohol absorption varies by type and person. Ketosis thresholds differ between individuals, and keto is not suitable during pregnancy or for people managing diabetes medication, kidney or liver disease, or a history of disordered eating without medical supervision. Treat the output as a planning guide.

Factors that change your keto macros

• Carb limit: the daily limit you set drives the split; lower carbs push fat higher.
• Calorie target: the goal sets total calories, and fat fills whatever protein and carbs leave.
• Activity: active people burn through glycogen and can often tolerate the upper end of the carb range.
• Individual threshold: the carb level that maintains ketosis varies from person to person.
• Adaptation: fluid, sodium, and energy shift in the first weeks as your body fat-adapts.
• Sugar alcohols: different types are absorbed differently, so net-carb estimates are approximate.