The age they were when you arrived
Most of us know roughly how old our parents were when we were born, but very few people know it to the day. It is a surprisingly moving number. It tells you how much life your parents had lived before you, what stage they were at, and what the world looked like for them. It also gives you a date of your own: the day you reach the same age. People often say that is when they first understand their parents a little better.
The timeline above shows your parents’ lives with yours underneath. Move the slider to any age and you can see how old they were then, which makes it easy to picture your childhood from their side: the year you started school, the year you left home, the year you turned the age they were when they had you.
How we calculate it
We count the calendar days from each parent’s birth date to yours and show that as years, months and days. For any point in your life, we add your age to your birth date and work out each parent’s age on that date. The “same age” day is your birth date plus the number of days your parent had lived when you were born. On that date you also pass the point of having been in their life for half of it.
| Year | Average age of a first-time mother in the US |
|---|---|
| 1970 | 21.4 |
| 1990 | 24.2 |
| 2010 | 25.4 |
| 2023 | 27.5 |
Worked example. Someone born on 12 April 1990, whose parents were born on 21 August 1962 and 5 March 1960, arrived when one parent was 27 years, 7 months and 22 days old and the other was 30 years, 1 month and 7 days. They reached the younger parent’s age on 2 December 2017 and the older parent’s on 19 May 2020. By 30 October 2026 they had been part of 57% of the younger parent’s life.
A conversation starter
Ask your parents what they were doing at the age they were when you were born, or at the age you are now. The answers tend to be better stories than any number. If your “same age” day is still ahead, it can be a quietly meaningful date to mark, perhaps with a call home.
Questions people ask
How old are most parents when their first child is born?
In the United States the average age of a first-time mother reached 27.5 in 2023, according to the CDC, up from about 21 in 1970. Research using US birth records put the average first-time father at around 31 in the mid-2010s. Many European countries are higher still, at 29 to 31 for mothers.
What is the “same age” date?
It is the day you become as old as your parent was when you were born. From then on, you will have been part of more than half of their life.
Can I leave the second parent blank?
Yes. Clear the second date and the page works with one parent. You can also use it for a grandparent, a step-parent or anyone who raised you.
Is anything saved?
Your own birthday is remembered on this device. Your parents’ dates stay only while the page is open.
Sources. CDC National Center for Health Statistics, births data (2023); Khandwala et al., Human Reproduction (2017). Calculations run in your browser; nothing you enter is sent anywhere.