 How to calculate age in Excel? All you need to do is enter equals date div with 1f open brackets. Select your start date which for us is going to be the birthday comma. Use the today function to get today's date and just ensure you use the open and close brackets at the end of that today function comma. In quotations do a lowercase y for year close brackets and hit enter and you can see Excel has now calculated the age from our birthday to the current date meaning that as time goes by this age will update dynamically for you. All you need to do is then copy that down to populate the age for all of your rows. If you enjoyed that video don't forget to give it a like and why not also subscribe to the channel for even more content.