Sports Age Group Calculator
Calculate age on an organizer's cutoff date and compare it with entered division bands. Choose the Feb 29 convention and reveal ambiguous overlaps.
Starts with an editable example. Replace the dates and rules with your own.
Your calculation
Ready when you are
Choose your dates.
Select your counting rules and calculate.
Calculation details
| Step | Value |
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How to use this calculator
Enter birth date, organizer cutoff, leap-day birthday rule and inclusive minimum/maximum ages for each division.
Age is completed calendar years on the cutoff. More than one matching division is reported as ambiguous; no division is silently selected from overlapping bands.
A worked example
A February 29, 2008 birth is age nineteen on February 28, 2027 under the February 28 convention, or eighteen if age changes March 1.
Are all sports age-group rules the same?
No. Organizers may use different cutoff dates, eligibility rules and divisions. Enter their published terms and confirm entry requirements separately.
Which calendar and years are supported?
Use Gregorian dates from 1900 through 2100, with results in that range. Daily plans allow up to 366 dates; dark-sky searches allow 31 nights. Durations, capacities and policy rules are supplied by you. Astronomy uses the bundled Astronomy Engine, sea-level geometry and browser time-zone rules. Timed exports use UTC instants; date-only events do not assign a clock time. Copy, CSV and print include calculation assumptions. Nothing is booked or scheduled outside this page.
What happens to my dates?
Calculations run on your device. Saving a calculation is optional and keeps it in this browser. A setup link contains the dates and settings you entered; anyone with the link can read them. Use one tab per saved calculator. Clear saved data from Privacy & settings.