Your Family Tree Explained

Cousin Calculator:

Download a copy here.


This is you, this is your family tree and this is your family tree explained.

You have parents and your parents have parents, these are your grandparents who also have parents, your great-grandparents. Keep adding parents, keep adding adding 'greats'.

For every 'g' in the name there is one generation in-between you and that person.

Grand parents? One 'g' one generational inbetweener. Great, great, great grand parents? Four 'g's four inbetweeners.

Continuing with the basics you have siblings and so do your parents: these are your Aunts and Uncles.

Up the tree you may call these people your great aunts and uncles, but your grand parents' siblings are really your grand aunts and uncles. 'Greats' are reserved for the levels above grand. Your great-grand parents' siblings are your great grand aunts and uncles.

Now down the tree your siblings' children are your nieces and nephews -- collectively niblings -- and you are their aunt or uncle. Their children are your grand nieces and nephews and you are their grand aunt or uncle.

We've gone up and we've gone down and now it's time to go sideways.

When you get married, you get everyone's favorite: in-laws! You are on the same level of the family tree as your spouse's siblings -- you're a kind of pseudo-sibling -- all the new family's relationships to you are the same as to your spouse, but they get the in-law suffix.

It's pretty straight forward except for one case: your spouse's siblings are your siblings-in law. But are your siblings's-in-law's spouses also your siblings-in-law? It's a little unclear.

Alright: enough with in-laws, it's on to the reason you're probably watching this video: cousins.

Your Aunt and Uncle's Children are your cousins, but there are many kinds of cousins and to better understand them we need to simplify this family tree and think downward.

Here's you, your children and your grand children. The grand children are first cousins to each other. And their children, your great grand children, are second cousins to each other, and so on.

The cousin number is the same as the 'g' rule: it tells you how many inbetweeners until the connection on the family tree. Fourth cousins cousins, four inbetweeners a shared great-great-great-grandparent.

According to the rule, your first cousin and you connect at your grand parent. Second cousins share a great, grandparent connection. Just match the number with the g's and you're all set.

Simple, huh?

Side note here: continuing this rule in reverse means siblings can technically call each other 0th cousins. Which they totally should. And you are you own negative first cousin? Weird.

All done here now, nothing more to talk about... oh right... the once-removed thing.

You may have noticed cousins are all on the same level. 'Removed' describes how many levels apart people are. What's the family connection between these two? Start by taking the smaller cousin number -- 1st cousins -- and count the levels down -- 'once removed'.

These are first cousins, twice removed. Thrice removed.

Second cousins, once removed.

Doing all this on our simplified drawing of your decedents is a bit too easy as most family trees look more like this. The rules are still the same, 1st cousins, 2nd cousins, and the removed -- but it's a bit harder to tell quickly who exactly is your second-cousin twice removed, or your great-grand aunt... in law.

To help there is a chart you can download which will both make it much easier to figure out what grand-nibling or cousin removed you are to anyone at the next family reunion more easily and, obviously, show how cool you are.

Now we're really done... unless you start thinking about the math of all of these family members -- just how many great-great-great-great- grandparents do you have? 64?

And those great x grand parents had kids, giving you a whole lot of cousins -- this chart happens to stop at 10th cousins, of which if you do may have more than 2,000? Which seems like too many, but these numbers both have big, possibly unsettling asterisks attached to them which we will talk more about in part 2: family genetics explained.