Health Tools
Ready to use — no sign-up, no download. Search or browse by category and dive in.
BMI Calculator
Enter height and weight to get your body mass index, category and a visual scale.
Use toolSleep Cycle Calculator
Work backwards in 90-minute sleep cycles to find ideal bed and wake times.
Use toolHeart Rate Zone Calculator
Divide training intensity zones from your max heart rate so every workout lands in range.
Use toolNap Calculator
Two-way nap timing: set your alarm from lie-down time, or work back from when you must be awake.
Use toolCaffeine Half-life Calculator
See how much of that afternoon coffee is still working in your body at bedtime.
Use toolCoffee vs Nap
Low afternoon energy — coffee or a nap? Compare alertness curves of three strategies.
Use toolJet Lag Calculator
Estimate recovery days by time zones crossed, with a day-by-day schedule and light tips.
Use toolBMR Calculator
Estimate the calories you burn at rest each day — the starting point of any diet plan.
Daily Water Intake Calculator
Estimate how much water you should drink based on weight and activity.