Age Calculator: Calculate Your Exact Age from Date of Birth
Free Age Calculator
Uses real calendar dates, including leap years. The result is chronological age only. Your dates are calculated in your browser and are not sent or saved.
What Is an Age Calculator?
An age calculator works out the time between a person's date of birth and a chosen date, and shows it as years, months and days. This is called chronological age: the time that has passed since birth, counted on the calendar.
By default the calculator uses today's date, but you can change Age at the date of to any date in the past or future. That makes it useful for checking age on a form's closing date, on the day of an exam, or on the date of a clinic visit. Along with the main result it shows your total months, weeks, days and hours, the weekday you were born, and a countdown to your next birthday.
How to Calculate Age from Date of Birth
Because months have different lengths, the calculator counts complete months first and then the leftover days. It follows these steps:
Worked example: born 15 May 1990, age on 20 October 2026.
- Complete months = (2026 − 1990) × 12 + (10 − 5) = 437. The target day (20) is not before the birth day (15), so nothing is subtracted.
- 437 months = 36 years and 5 months.
- 15 May 1990 plus 437 months is 15 October 2026, and 20 October is 5 days later, so the leftover is 5 days.
- Result: 36 years, 5 months, 5 days (13,307 days in total, which is 1,901 weeks).
Age in Months and Weeks (Babies and Children)
In the first two years of life, a child's age is commonly counted in weeks and months rather than years, so the calculator always shows age in months (with leftover days) and age in weeks (with leftover days) next to the main result.
The table below gives rough conversions using an average month of 30.44 days. Real calendar months differ in length, so use the calculator for the exact figure.
| Age in months | Approx. days | Approx. weeks |
|---|---|---|
| 1 month | 30 | 4.3 |
| 3 months | 91 | 13.0 |
| 6 months | 183 | 26.1 |
| 9 months | 274 | 39.1 |
| 12 months | 365 | 52.2 |
| 18 months | 548 | 78.3 |
| 24 months | 730 | 104.4 |
Why Exact Age Matters in Healthcare
- Vaccination timing. The CDC's child and adolescent immunization schedule lists the recommended vaccines by age, from birth and the first months through childhood to 18 years. Schedules differ from country to country, so follow the one your doctor or local immunization programme recommends.
- Growth monitoring. The CDC and the American Academy of Pediatrics recommend the WHO Child Growth Standards for children from birth to 2 years, and CDC growth charts for ages 2 to 20 years. A child's measurements are read against their exact age.
- Age-based checks and forms. Screening, school admission and many application forms ask for age in completed years, or age on a particular date.
Babies born early may be assessed by their doctor using a corrected age for development checks. This calculator shows chronological age only.
Age on a Specific Date (Cutoff or Closing Date)
Admission forms, job advertisements and exam notices often ask for your age as on a fixed date. To find it, enter your date of birth, then type that date in Age at the date of and press Calculate.
The calculator only does the date arithmetic. Whether a person is eligible is decided by the rules of the institution or authority that issued the notice, so always check their instructions.
Leap Years and Month-End Dates
If the birth day does not exist in a month, the calculator uses the last day of that month. Example: a person born on 31 January 2024 is, on 1 March 2024, 0 years, 1 month and 1 day old. One month after 31 January is taken as 29 February 2024 (a leap year), and 1 March is one day after that.
People born on 29 February have a birthday on 28 February in years that are not leap years for the purpose of the next birthday countdown.
Next Birthday and Day of Birth
Below the result you will see how many days remain until the next birthday, the weekday it falls on, and the age being turned. For example, someone born on 15 May 1990 was born on a Tuesday, and on 20 October 2026 their next birthday is in 207 days, on Saturday, 15 May 2027, when they turn 37.
Age Calculator FAQs
How do I calculate my age from my date of birth?
Subtract your date of birth from today's date. Count the complete months between the two dates, divide by 12 for the years, and the leftover months and days make up the rest. For example, someone born on 15 May 1990 is 36 years, 5 months and 5 days old on 20 October 2026. This calculator does all of that automatically.
How do I calculate age in months?
Count the complete calendar months from the date of birth to the chosen date, then add the leftover days. The calculator shows this as Age in months. A baby born on 10 January who is checked on 25 April of the same year is 3 months and 15 days old.
How many weeks old is my baby?
Divide the baby's age in days by 7 and round down to get completed weeks, with the leftover days shown separately. The Age in weeks card does this for you. Weeks are commonly used for young infants, and months for older babies.
What is chronological age?
Chronological age is the time that has passed since a person was born, counted from the date of birth. It does not account for how early a baby was born, so doctors may use a corrected age for babies born preterm. This calculator shows chronological age only.
How do I calculate age on a specific date?
Enter the date of birth, then change the Age at the date of field to the date you need, such as a form's closing date or an exam date. The calculator returns the exact age on that date, in the past or the future.
How does the calculator handle leap years and 29 February?
It uses the real calendar, so leap years are counted correctly. If a birth day does not exist in a month (for example the 31st in a 30-day month), the last day of that month is used. For people born on 29 February, the next birthday countdown uses 28 February in years that are not leap years.
Can I use this calculator to decide a child's medicine dose?
No. The calculator only shows age. Many children's medicine doses depend on body weight and on the specific medicine, not on age alone. Always follow the dose written on the label or prescribed by your doctor or pharmacist.
Does Medinzo save my date of birth?
No. The calculation runs in your browser, and this page does not send or store the dates you enter.
Age calculator se umar kaise maloom karen? (اردو میں جواب)
اپنی تاریخِ پیدائش درج کریں اور Age at the date of میں وہ تاریخ رکھیں جس پر عمر معلوم کرنی ہے (عام طور پر آج کی تاریخ)۔ Calculate دبانے پر آپ کی عمر سال، مہینے اور دن میں آ جائے گی، ساتھ میں کل مہینے، ہفتے، دن اور اگلی سالگرہ بھی نظر آئے گی۔
Roman Urdu Summary (خلاصہ)
- Age calculator kya karta hai? Ye date of birth se aaj ki (ya kisi bhi) date tak ki umar saal, mahine aur din mein batata hai.
- Misal: 15 May 1990 ko paida hone wala shakhs 20 October 2026 ko 36 saal, 5 mahine aur 5 din ka hai.
- Kisi khaas date par umar: "Age at the date of" mein form ki closing date ya exam ki date daal dein.
- Bachon ki umar: Pehle 2 saal mein umar aam taur par hafton aur mahinon mein dekhi jati hai, is liye calculator mahine aur hafte bhi dikhata hai.
- Dhyan rakhein: Ye calculator sirf umar batata hai. Bachon ki dawai ki dose aksar wazan aur dawai ke hisab se hoti hai, umar se nahi. Dose hamesha doctor ya label ke mutabiq lein.
References & Sources
- Centers for Disease Control and Prevention (CDC). Child and Adolescent Immunization Schedule by Age.
- Centers for Disease Control and Prevention (CDC). Training Module: Using WHO Child Growth Standards.
- World Health Organization (WHO). The WHO Child Growth Standards.