Four generations in one photo
A photo of great-grandparent, grandparent, parent and baby together is a treasured thing in many families. It only exists if the lives overlap: the oldest has to live long enough, and each generation has to have children early enough, for all four to be alive in the same year. This page lays every generation of your family along one timeline and counts, year by year, how many of you were alive. The coloured band at the bottom shows the count, with the busiest years highlighted.
Fill in the years you know. For older relatives a birth year from a family record or a headstone is plenty. If you do not know the year someone died, an estimate still gives a good picture.
How we calculate it
For every calendar year from the oldest birth to today, we count each person who was born in or before that year and had not died before it. Anyone without a death year is treated as living. The years with the highest count are the peak overlap. A person counts for the year of their birth and the year of their death, so two lives that touched within one calendar year are counted as overlapping.
| Average gap between generations | Years from you back to a great-great-grandparent |
|---|---|
| 25 years | 100 |
| 28 years | 112 |
| 30 years | 120 |
| 33 years | 132 |
Worked example. Take someone born in 1990 whose great-grandparent lived from 1905 to 1994, whose grandparent lived from 1935 to 2019, whose parent was born in 1962 and whose own child was born in 2018. Their family had four generations alive at once twice: from 1990 to 1994, and again in 2018 and 2019. In 2026 three generations are alive.
Why it matters
Grandparents and great-grandparents who are part of a child’s life are often the family’s keepers of memory. Knowing how long the generations overlapped is a good prompt to collect those stories while you can: ask the oldest members of your family what they remember of their own grandparents, and you can reach back a century or more in one conversation.
Questions people ask
How common are four-generation families?
More common than they used to be. Longer lives mean many children now meet a great-grandparent, although people having children later pulls the other way. Five living generations at once is still rare and usually needs young parents in every generation.
Why do you only ask for years?
Most people know the birth year of a grandparent or great-grandparent but not the exact date. Years are enough to show when the generations overlapped. Overlaps are counted by calendar year, so a single shared year counts even if the two lives met for only a few months.
What should I put for someone who is still alive?
Leave the second year empty. The page treats them as alive today. Leave a whole row empty to skip that generation.
Is anything saved?
No. The years stay only while the page is open.
Sources. Family years you enter; overlaps counted by calendar year. Calculations run in your browser; nothing you enter is sent anywhere.