How to Calculate Age from Date of Birth
Step-by-Step Calculation
Example 1 — Birthday already passed this year
Date of birth: March 15, 1990 · Today: June 6, 2026
- Years: 2026 − 1990 = 36. Birthday has already passed this year ✓
- Months since March 15: April (1), May (2), part of June = 2 complete months
- Days remaining: 22 days into the current month
- Result: 36 years, 2 months, 22 days
Example 2 — Birthday not yet passed this year
Date of birth: September 20, 1995 · Today: June 6, 2026
- Years: 2026 − 1995 = 31. Birthday has NOT passed yet → subtract 1
- Actual years: 30. Last birthday was September 20, 2025
- Months since Sep 20, 2025: Oct, Nov, Dec, Jan, Feb, Mar, Apr, May = 8 complete months
- Result: 30 years, 8 months, 17 days
Example 3 — Birthday is today
Date of birth: June 6, 1988 · Today: June 6, 2026
- Years: 2026 − 1988 = 38. Today IS the birthday ✓
- Result: Exactly 38 years, 0 months, 0 days — Happy Birthday! 🎉
Why Exact Age Matters
| Use Case | What is Required | Why It Matters |
|---|---|---|
| Indian Passport | Age in completed years | Determines passport validity (5 or 10 years) |
| Visa Applications | Exact DOB + age at travel | Many countries have age cutoffs for visa categories |
| School Admissions | Age on a specific cut-off date | Class 1 requires child to be 6 by June 1 or July 31 |
| Government Job Forms | Age as of a specific date | UPSC, SSC exams have maximum age limits to the day |
| Senior Citizen Benefits | 60 years completed | Railway discounts and tax deductions change on exact 60th birthday |
🎂 Calculate Your Exact Age Instantly
Get your age in years, months, days, hours and minutes — plus your next birthday countdown. Free, no sign-up.
Open Age Calculator →Tricky Age Calculations
Born on February 29 (Leap Day)
People born on February 29 only have a true birthday every four years. In most legal contexts, the birthday is observed on March 1 in non-leap years. Always check the specific rules for the document you are completing.
Age as of a past or future date
Many official forms ask for age "as of" a specific date. Substitute that date for "today" in the formula above — do not use today's actual date.
Age calculation in Excel
Frequently Asked Questions
How is age calculated for Indian passport applications?
Age is calculated in completed years as of the date of application. If you are 17 years and 11 months old on the day you apply, you are classified as a minor. The exact day matters.
How many days old am I?
Multiply your age in years by 365, add roughly 1 day per 4 years for leap years, then add days since your last birthday. The quickest method is to use the Age Calculator above — it shows total days lived instantly.
Is my age different in different countries?
Legally, no. Age is based on your date of birth and the Gregorian calendar, which is universal. South Korea's traditional system counted 1 year at birth, but this was officially abolished in 2023.
How do I calculate age for school admissions in India?
For Class 1 admissions, most Indian states require the child to be at least 6 years old as of a specific cut-off date — typically June 1 or July 31 of the academic year. Each state's RTE rules may differ slightly.