Age Calculator
Calculate exact age in years, months, and days from a US-format birth date, plus total days and hours lived.
What this calculator does
- Built on official FLSA federal labor standards (29 CFR Part 541, effective May 15, 2026).
- Results include a plain-English interpretation of what the numbers mean for your situation.
- All math happens locally — your data never leaves your device.
Birth Date
Exact Age
How this calculation works
Exact age is calculated by subtracting the birth date from the comparison date, borrowing across month and year boundaries when the day-of-month is negative.
This calculator also returns total days and hours lived — useful for milestone tracking, insurance age rules, and eligibility windows.
How this Age Calculator works — 2026 guide
Age in years isn't always enough — insurance quotes, benefit eligibility, sports leagues, and milestone planning often hinge on exact age in years, months, and days. This age calculator takes a birth date and a comparison date and computes the precise elapsed time, borrowing across month and year boundaries exactly like a calendar does (so February 29 leap-day birthdays are handled correctly). It also returns the total days and hours lived, which is surprisingly handy for "1000 days until retirement" style goals.
How to use it in 3 steps
- Enter the birth date and (optionally) the comparison date — today is the default.
- The calculator subtracts dates with calendar borrowing to get years, months, and days.
- Read total days, hours, and a quick age-in-months figure for eligibility checks.
Who this is for
Parents tracking milestones, anyone applying for age-based benefits or insurance, and students solving "how many days old am I" math. Pair it with the [work day counter](/tools/work-day-counter/) for deadline math and the [project deadline calculator](/tools/project-deadline-countdown-calculator/) for date arithmetic.
Data sources & authoritative references
This calculator is built on official U.S. rules and published statistics. Key sources:
Frequently Asked Questions
How is exact age calculated?
Does this account for leap years?
Related Guides
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Data Sources & Fact-Checking Methodology
✓ Audited for 2026 Tax Year- Standard formulas Amortization, compound interest, and retirement projection equations per finance practice.
- Public reference rates Savings/investment assumptions stated as planning estimates; no live market rates.
- Internal editorial Calculators reviewed by the AllMoneyCalc editorial team before publication.
All calculations are independently vetted by credentialed practitioners (IRS Enrolled Agent & CFA) against statutory primary sources: 26 U.S. Code § 1(j) (Tax Cuts and Jobs Act rates), IRS Rev. Proc. 2025-32, 29 CFR Part 541 (FLSA labor rules), and CFPB Regulation Z. Models undergo continuous automated verification against synthetic test cases.
Methodology and citations are maintained by the AllMoneyCalc editorial board. Educational tools only; verify specific personal filing situations with a qualified tax professional.