Calorie calculator
Your daily calorie target and macros — from the Mifflin–St Jeor equation, with the reasoning shown.
Estimates use the Mifflin–St Jeor formula for general guidance only — not medical or nutrition advice. Everyone's needs differ; consult a professional. Don't use this if you have an eating disorder or a medical condition.
Turn your number into a plan
Kairo builds your fasting window around this target and fills it with meals that fit — personalized and explained.
Build my full plan — freeHow this calorie calculator works
It uses the Mifflin–St Jeor equation — the formula most dietitians consider the most accurate everyday estimate of resting metabolism — then multiplies by your activity level and adjusts for your goal (a modest deficit to lose, a small surplus to gain). Protein is set high (~30% of calories) because it protects muscle and keeps you full, which matters double if you're eating in a fasting window.
Is the target safe?
The calculator never recommends below 1,200 kcal/day (women) or 1,500 kcal/day (men) — if the math lands lower, it raises the target to that floor. These are general guardrails, not medical advice.