Free Health & Everyday Calculators

Free calculators for health, dates, and school — factual and plain-English, with the method shown, not just an answer. Check your BMI and estimate the calories you burn each day (BMR and TDEE), plan bedtimes around 90-minute sleep cycles, or estimate a pregnancy due date and how far along you are. Count the exact time between two dates, work out your precise age and the countdown to your next birthday, find the exam score you need to hit a target grade, and compute a weighted or cumulative GPA on the 4.0 scale. Everything runs on your device the moment you type — nothing you enter is sent anywhere.