BMI, calorie estimates, sleep cycles, age math, and cooking conversions — quick checks in the browser.
Height and weight → BMI with category label.
Rough BMR and TDEE via Mifflin–St Jeor with activity multiplier.
Bedtime or wake times aligned to ~90-minute cycles.
Exact age or difference between two dates.
tsp, tbsp, cup, ml, and common volume ↔ grams for water-like density.