Simple, accurate calculators with the method explained on every page. Everything runs in your browser — nothing you enter is stored.
Exact age in years, months and days, with total weeks, hours and next birthday.
Add or subtract days, hours, minutes and seconds — or shift a date and time.
Convert a date and time between world time zones, with daylight saving handled.
Grade point average from credits and grades, with a GPA target planner.
Predict a child's adult height from the parents' heights and convert ft/in to cm.
Convert length, area, volume, weight, temperature, time and speed units.
Area of rectangles, circles, triangles and more, with optional cost.
Estimate the voltage drop of a copper or aluminum wire run.
IPv4 and IPv6 network, broadcast, host range, masks and address type.
Strong random passwords generated in your browser, with entropy shown.
GDP by the expenditure and income approaches, plus growth and per-capita.
More financial, fitness & health and math calculators are being added. Need a custom tool for your own website? See our website designing services.
