Keto Calculator

What the keto calculator does

Eating for ketosis means watching every macronutrient, not just calories. This keto calculator builds a personal macro plan by estimating the calories you burn each day, then splitting them into fat, protein, and net carbs sized to keep you in ketosis.

It suits two very different groups: beginners who need starting numbers for their first keto week, and experienced low carbers recalibrating after a weight change. Athletes and keto cooks use it too, adjusting the fat slider for performance or recipe design.

From Mifflin St Jeor to macros

The engine starts with the Mifflin St Jeor equation to find your basal metabolic rate: for men, 10 times Weight: in kg plus 6.25 times Height: in cm minus 5 times Age: plus 5, and women subtract 161 instead of adding 5. An Activity Level: multiplier scales BMR up to total daily energy, and the shortfall for weight loss is subtracted. Protein is set from lean mass, net carbs are capped low, and fat fills every remaining calorie.

Example: a 35 year old man, 180 cm and 80 kg, moderately active, burns about 2,700 kcal a day. Typical keto targets give him roughly 155 g protein, net carbs under the customary 25 to 30 g ceiling, and fat near 215 g, matching the classic 70 to 75 percent fat, 20 to 25 percent protein keto profile.

Using the results well

Set Imperial or Metric, enter Age:, Male or Female, Height:, Weight:, and Activity Level:, then the calculator returns grams of fat, protein, and net carbs alongside calories. Treat net carbs as total carbs minus fiber, since fiber passes through undigested and does not interrupt ketosis.

The biggest pitfalls: counting total instead of net carbs, ignoring hidden sugars in sauces, and stacking protein above target, which can quietly trim ketone production. Recalculate after every 4 to 5 kg of change, because macro needs shrink as you lose weight.