Utility Calculators
General-purpose utility and helper calculators.
Everyday utilities that are live
These are the helpers that are not a school formula or a loan. Each one runs in the browser.
- Age difference between two birth dates.
- Half birthday six months from a birthday.
- Birthday rarity for how common a date is.
- Sleep calculator for a wake time on a 90-minute cycle.
Open the homepage if the job you need is a fraction, a tip, or a grade instead.