Hi ​@Eline88254 - Currently, you can only have one duration per event, so there is not a way to allow an invitee to choose their duration from your booking page. We recommend creating an event for each duration you’re offering, then allowing your invitee to choose from your public events page (ex. calendly.com/(YOUR-LINK))

However, I do think this is a good idea, so I’ve sent it off to our product team to review. Let me know if you have any questions!

​@David Waiting for this feature
This thread is about the same thing: https://help.calendly.com/hc/en-us/articles/1500000111042-How-to-change-the-duration-of-an-event-type-within-the-mobile-app