What is a grandparent?

2 min readUpdated 19 October 2026

Short answerYour grandparent is your mother’s or father’s parent. You are their grandchild. A grandparent is a direct-line ancestor, 2 generations above you. You inherit about 25% of your DNA from each grandparent on average.

The family line, drawn out

Follow the highlighted line from you up to the shared ancestor and down to them.

Themyour grandparentParentyour parentYoustart here
2 generations apart in a direct line.

How to work it out

Count the generations straight up: parent is 1, grandparent 2, great-grandparent 3. A grandparent is 2 up. From 2nd great-grandparent on, genealogists number the “greats” to keep them readable: a 3rd great-grandparent is a great-great-great-grandparent.

Everyone has 4 grandparents by birth, 2 on each parent’s side, unless the same person appears twice in the tree (cousins who married, which genealogists call pedigree collapse). Family Trees always takes the shortest line, so someone who is both a grandparent and a great-grandparent reads as grandparent.

What to call each other

Them, to youYou, to them
Femalegrandmothergranddaughter
Malegrandfathergrandson
Anyonegrandparentgrandchild

Their family and yours

Relationships shift by one step for each generation. Here is how the people around them relate to you:

Their other children (not on your line)aunt or uncle
Your child sees them as your child’sgreat-grandparent
Your parent sees them as your parent’sparent
What they call yougrandchild

Shared DNA

On average, you inherit about 25% of your DNA from a grandparent. That figure is the expected value: it halves with every generation of separation, and real amounts vary from person to person.

Let Family Trees name it for you

In Family Trees, open anyone’s page to see how they are related to you in plain words, or choose any two people under How are they related?. The app counts the shortest blood line through birth and adoptive parents, names step, foster and in-law relations too, and uses exactly the words on this page. It’s free for a family of up to 100 people. You can also try the relationship calculator here.

Questions

What is a grandparent?

Your grandparent is your mother’s or father’s parent. You are their grandchild.

How many grandparents do I have?

Everyone has 4 grandparents by birth, 2 on each side, unless an ancestor appears twice because relatives married each other.

How much DNA do you share with a grandparent?

About 25% on average. Each generation of separation halves the expected amount, and individual results vary.

What is my grandparent’s child to me?

Your aunt or uncle, on the same line.