Excel Hints & Tips - Calculating Age
You’d think that there would be an AGE function that worked out how many years since the anniversary by passing in a date. However, life is not that easy.
Hi, we are Happy
We are leading a movement to create happy, empowered and productive workplaces.
How can we help you and your people to find joy in at least 80% of your work?
Our trainer Ian Balboa explains step-by-step how to calculate how many years since an anniversary – both the easy way and the hard way.
The Easy Way
There is a function called DATEDIF that does something similar. The bad news is that for some reason Microsoft no longer supports this function in Excel. You can still use it, but you don’t get any help with it. For example, you have to remember the order of the arguments that go into the function, there’s no handy pop-up box to give you a hint. So, if you’re like me, you will probably end up typing it in multiple times with the arguments in different orders until it works!
Here’s the structure of the function:
=DATEDIF (Earliest Date, Later Date, Time Interval)
The Earliest Date will be the date you are working with, for example the Date of Birth. The Later Date will be today’s date, which you can get with the TODAY function. The Time Interval is how you want to express the difference between the two dates. If you are working out age, then you will need to specify the interval as years by using the code “y”. If your Date of Birth is in cell A1, then the completed formula will look like this:
The DATEDIF function automatically takes into account if the person’s birthday has already occurred this year. If not, it will subtract one from the resulting age.
The Hard Way
If you don’t want to use the unsupported DATEDIF function, then you can still work out an age from a Date of Birth, but it requires a little fancier Excel Kung Fu. There is a useful function called YEAR that will take a date and return the year bit of that date. For example, if you have the date 01/Dec/1970 in cell A1 then =YEAR(A1) will return 1970. (This date is very important as it’s my birthday!)
You can combine two YEAR functions to work out the difference in years between two dates:
At the time of writing the date is April 2013, so the above formula would give 2013-1970, which equals 43. Sounds good so far, yes? Except, of course, I haven’t had my birthday yet, so I am actually only 42. (The extra year is increasingly important when you get to my age…)
So, to make this work, we need to somehow decide whether or not the anniversary of the date has passed. If it hasn’t, then we need to subtract one from the resulting age. This is the fancy bit!
In fact there are several ways to do this; what follows is, I think, a relatively straightforward method. We are going to work out the day of the year for each date. By this I mean: which day, out of 365, have we reached within the year in question? We can then compare the two numbers, and if the day-of-the-year number for our date of birth is less than the day-of-the-year number for today’s date, then we haven’t had our birthday yet.
Let’s break this down into parts. The first part will be to work out the day-of-the-year-number for our date of birth. We can do this by taking the date of birth and subtracting the 1st of January of that year from it. When you subtract one date from another, you get the difference between those dates in days. To create the 1st of January for year X we use the YEAR function, which we have already seen, and the DATE function. The DATE function creates a date from the three parts we supply: the year, month and day. If the original date is 01/Dec/1970, which is in cell A1, then the formula is:
This gives us the difference is days between the date in A1 and the 1st of January 1970. (Don’t worry; it takes leap years into account!)
If we do the same for today’s date, using the TODAY function, then we get something like this:
The next step is to compare these two values using an IF function and return either 1, if the birthday hasn’t happened, or 0, if it has.
If the day-of the-year-number for the date of birth is bigger than today’s day-of-the-year number, then this means we haven’t had our birthday yet.
The final step is to put all this together into one long formula. It looks pretty scary, but if you break it down into parts, then it’s not so bad.
Don’t forget to format the result of this formula as a number; otherwise you will get some strange results.
Why not sign up to our newsletter?
Sign up to our monthly newsletter, full of tips, tricks and news to help you to be happier and more productive at work.
Ian was an IT trainer with Happy from 2007 to 2018, first as a member of staff and then as an associate. He delivered IT training in Microsoft Office (Word, Excel, PowerPoint, Access, Outlook) as well as VBA, SQL, HTML and Photoshop.
Testimonials from happy Customers
Trusted Customer26 days ago
I don't know about their service - I only interacted with the training.
Sam Haworth Booth26 days ago
Really interactive training with a facilitator with real-world experience who was able to encourage reflective practice in participants
Mary Murphy29 days ago
It was really interesting and helpful. Darren was so informative!
Diane Hellawell30 days ago
I really enjoyed the day. Very good trainers, easy to understand and a fun interactive day. looked after really well, plenty of Tea, Coffee, Snacks throughout the day, ni...
Roy Wood30 days ago
A well-structured training course, which was really well delivered. Course content (including handouts) sufficiently covered key topics.
Trusted Customer32 days ago
The trainer was engaging and interacted well with the course participants, but the course content didn't feel particularly well tailored to the group's needs, which was f...
Trusted Customer32 days ago
Very upbeat and engaging
Trusted Customer33 days ago
Interesting and informative session. Helped my understanding.
Trusted Customer33 days ago
Very good tutor. I enjoyed the interactive nature and practical exercises.
Tomisin Olumoroti33 days ago
Lovely session and I plan on booking another session in the near future with Happy so that I continue learning and growing in Excel.
Ben Mountford34 days ago
Very good service, patient and polite also able to have a laugh and joke as the course went on. Great to refresh and also learn the new capabilities of excel, especially ...
Liz Mulholland37 days ago
very informative and engaging also being able to connect with people from all over the world