Blaked added it felt right "going out on a high".
"We've never loved doing radio as much as we love doing it now. That's a perfect time to end - we're not ending tomorrow, we've still got another full year, we can really savour it," he added.
Lee said the pair considered quitting the gig this year, but decided to give it 12 more months.
"We were potentially thinking about ending on radio this year but we were just having too much fun," Andy Lee said. "We just had to keep going."
Hamish and Andy became a comedy duo in 2003 after they met while studying commerce at the University of Melbourne.
They began presenting a radio show on the Student Youth Network and a TV sketch show called Radio Karate, and became a household name after they began hosting the drivetime Hamish and Andy Show every weekday on the Hit Network.
It has become the highest-rating radio series in Australian history.
They made a brief appearance on Neighbours in 2008 and made their own TV shows Hamish and Andy's Gap Year and Caravan of Courage, a two-parter in which they compared Australia and New Zealand.
A 10 Years in 10 Weeks special airs Monday 16 January 2017 while they complete their new TV show, created by their production company Radio Karate, which they hope will get picked up by Channel Nine.
Hamish also appears in a supporting role on The Wrong Girl, based on his wife Zoe Foster Blake's best selling novel of the same name.
From Monday 27 March they return live to the drive shift for their final year of Hamish & Andy as we know them now.