Average Age from DOB Field - MySQL / PHP

Question

I wasn't sure how I could calculate the average age of my contacts who all exist in a mysql table with a DOB date field such as YYYY-MM-DD. Is there a way to do with with a MySQL call (please note I am using cakephp but that shouldn't be an issue) Thanks

Accepted Answer

You can determine age by using `DATEDIFF()`:

```
DATEDIFF(TO_DAYS(NOW()), TO_DAYS(DOB))
```

The average is found in MySQL using `AVG()`:

```
AVG(Column)
```

So combine those:

```
SELECT AVG(DATEDIFF(TO_DAYS(NOW()), TO_DAYS(DOB))) as `Average` FROM Contacts;
```

Note that this returns the average age in days, not years. To obtain years you can average the years part of each date:

```
SELECT AVG(DATEDIFF(YEAR(NOW()), YEAR(DOB))) as `Average` FROM Contacts;
```

Or as @TimDearborn suggested, divide the day average by 365.242199.

Average Age from DOB Field - MySQL / PHP

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