Age Calculator — Years, Months & Days
Calculate your exact age in years, months and days from your date of birth.
By Konstantin Iakovlev · Founder, Calks.uk
Last updated: · Verified against HMRC and GOV.UK 2026/27 rates
Disclaimer
This calculator is provided for informational purposes only and should not be considered as financial or tax advice. All calculations are performed locally in your browser — no personal data is collected or sent to our servers. Rates and thresholds are sourced from HMRC and GOV.UK and are updated for the current tax year. Always verify results with HMRC or consult a qualified professional before making financial decisions.
How It Works
This calculator works out your exact age in years, months, days, hours and minutes from your date of birth. It accounts for leap years, varying month lengths and the current UK time zone (GMT or BST depending on the date).
Knowing your precise age is useful for checking pension eligibility (State Pension age is currently 66, rising to 67 between 2026 and 2028), insurance quotes, driving licence applications and legal age thresholds such as 18 for voting or buying alcohol.
The calculator also shows your age on any future or past date, not just today. Enter a target date to see how old you will be — or were — at that point. It displays the result in multiple units so you can see your age in total days or hours lived.
Age calculation method. The standard approach: start with current_year minus birth_year, then subtract 1 if your birthday hasn't happened this calendar year. For months, take current_month minus birth_month (borrowing from years if negative). Days follow the same logic, borrowing from months. UK legal convention: you turn 18 on the anniversary of your birth (00:00 on your birthday) — not the moment of birth, and not the day before.
UK age milestones with legal and tax weight. 13: light part-time work permitted. 16: leave school (England), consent to medical treatment, buy lottery ticket, marry in Scotland with consent. 17: provisional driving licence. 18: full legal majority — vote, contract, jury service, alcohol purchase. 25: full National Living Wage rate (£12.21/hr 2026/27). 55: minimum pension access age (rising to 57 in April 2028). 66: current State Pension age (rises to 67 between 2026-2028, 68 from 2044). 75: free TV licence (restricted to Pension Credit recipients since 2020).
Age in total days, weeks and months. Average year = 365.2425 days. Sample milestones: 18 years ≈ 6,575 days = 939 weeks = 216 months. 30 years ≈ 10,957 days. 65 years ≈ 23,741 days. 100 years ≈ 36,525 days. February 29 birthdays celebrate legally on 28 February in non-leap years for most UK purposes (driving licence, alcohol law). UK life expectancy at birth (ONS 2023): 79.0 years male, 82.8 female — well below 1990s projections after stalled longevity gains in 2010s.
Age difference between two people. Subtract one DOB from the other. Pension survivor benefits, life insurance pricing and Inheritance Tax planning all weight age gaps heavily. A 10+ year age gap to spouse triggers higher annuity rates (younger surviving spouse means longer payout) but lower upfront pension transfer values. Marriage Allowance: £252/year tax saving available regardless of age gap (one partner non-taxpayer, other basic-rate).
Why precise age matters. Insurance quotes change on your birthday (sometimes the night before — most insurers use 23:59 on day-before-birthday). DVLA renewal at 70 then every 3 years thereafter — a key trigger date. State Pension claim window: 4 months before pension age. ISA contribution year reset at 6 April (not your birthday). Child Trust Fund (born 2002-2011) accessible at 18. Junior ISA converts to adult ISA automatically at 18.
Example: Born 15 March 1990
- Age today (April 2026): 36 years, 0 months, 27 days
- Total days lived: approx. 13,176
- Total hours: approx. 316,224
- Next milestone birthday (40): 15 March 2030
Frequently Asked Questions
- How is age calculated when months/days roll over?
- Standard method: years = current year − birth year, then subtract 1 if you haven't reached your birthday this year. Months = current month − birth month (borrow from years if negative). Days = current day − birth day (borrow from months if negative). UK convention: you turn 18 on the anniversary of your birth, not the day before. February 29 birthdays celebrate on either 28 Feb (England, Wales, NI for legal purposes) or 1 Mar in non-leap years — varies by personal preference.
- Age in days, weeks and total months.
- Total days = (today − birth date) in calendar days. Average year = 365.2425 days. Common conversions: 18 years ≈ 6,575 days = 939 weeks = 216 months. 30 years ≈ 10,957 days = 1,565 weeks = 360 months. UK State Pension age (2026): 66 ≈ 24,107 days. Median UK life expectancy at birth (ONS 2023): 79.0 male, 82.8 female. Centenarian threshold: 36,525 days.
- UK age-based rights and milestones.
- Key UK ages: 13 — work part-time (light duties); 16 — leave school in England (or stay till 18 in training), marry with consent (NI/Scotland), buy lottery ticket, consent to sex; 17 — drive a car; 18 — vote, buy alcohol, sign contracts, full legal adulthood; 21 — supervise learner driver, adopt; 25 — entitled to National Living Wage full rate; 55 — access defined-contribution pension (rising to 57 from April 2028); 66 — State Pension age (rising to 67 by 2028).
- Age difference between two people.
- Subtract one DOB from the other in years and months. Example: born 15 Mar 1980, partner born 22 Sep 1985 — partner is 5 years 6 months 7 days younger. Tax/legal relevance: spousal age gaps over 10 years can affect pension survivor benefits, inheritance tax planning, and certain insurance products. State Pension top-up for spouses no longer available since New State Pension rules (2016).