Everyday calculators
Everyday
Workdays between two dates, age, tips, duration math, or hours on a timesheet.
In this topic
Calculators
01GSA Per Diem Trip CalculatorFederal travel per diem for a trip in the continental U.S.: the GSA lodging ceiling for every night, meals and incidentals for every day, and a check of your actual room rate against the cap. Type a city or ZIP.02Business Days CalculatorCount workdays between two dates, or add workdays to a date. Federal holidays are optional.03Tip CalculatorTip amount, bill total, and an even per-person split from the subtotal and tip percent you enter.04Age CalculatorCompleted years, months, and days from a birth date to a selected as-of date, including leap-day rules.05Time CalculatorAdd or subtract hours, minutes, and seconds as durations. Negative results stay signed and normalized.06Random Number GeneratorGenerate one or more numbers in a range, including unique integers. Ordinary utility randomness, not a cryptographic tool.07Time Card CalculatorAdd shift start, end, and unpaid break across one or more days, including overnight shifts. Overtime law is not applied.08Date CalculatorFind the calendar date a given number of days, weeks, months, or years before or after another date. Month ends are clamped.09Days From Today CalculatorThe calendar date that is N days from today, or N days ago. Weekends still count; this is not business days.
How these are built
Every calculator shows its work.
Each one names the formula it used, and the dated official source behind any figure it did not get from you.
How the numbers work →