Discover practical calculations that do not fit neatly into the other collections.
How to calculate movie end time
Add a movie runtime to its start time, account for trailers, and handle a finish after midnight. A clock and elapsed-time ribbon make each step visible.
Foot length and shoe size: how the conversion works
Measure heel-to-toe foot length and see what a simplified shoe-size formula can—and cannot—tell you. The animation explains unit conversion, sizing offsets and brand-specific fit.
How to calculate words correct per minute
Separate correct-word rate from reading speed and accuracy. A timed passage demonstrates subtraction, seconds-to-minutes conversion, and the limits of a rate score.
How to calculate length of service between dates
Count elapsed days and calendar years, months and days between two dates, with clear endpoint and leap-year conventions.
How to convert FTE to hours
Convert a full-time-equivalent ratio to hours using a stated full-time schedule. At 40 hours per week, 0.75 FTE means 30 hours; with a 35-hour standard, it means 26 hours 15 minutes. Includes reverse checks and weekly versus annual assumptions.
How to calculate 48 hours from a starting time
Learn how to add 48 elapsed hours to a starting instant, convert the result to a named time zone, and distinguish that interval from two calendar days when daylight saving time changes.
How to calculate employment duration between dates
Calculate the elapsed calendar days between employment dates, understand leap-year anniversaries, and choose the correct rule for inclusive days or workdays.
How to calculate half-day time and a midpoint
Find half of a work duration, add it to a start time, and distinguish that from the midpoint of an entire clock interval. An eight-hour shift, a break, and an overnight example show when the answers differ.
How to convert human age to vampire age (a fictional rule)
Explore a fictional human-to-vampire age rule with an animated pair of timelines. Build the formula from its anchor and ten-to-one change, calculate 30 → 220, and reverse the result.