The former World number two will call time on her playing career at the end of the month after the British Open.
“It’s been on my mind for a while and it feels like a weight has been lifted from my shoulders now that this is out there,” said the 36-year-old ex-Harrogate Grammar School pupil.
“It’s definitely the right time, for the last few years my form hasn’t been great.
“You have to be realistic. I’ve recently had a hip operation and physically I can’t keep up with the level of the women’s game.
Kayne Ramsay impresses on Harrogate Town debut just hours after meeting team-mates for first time following Southampton FC switch
Harrogate Town 0 Crawley Town 0: Advertiser player ratings
Kayne Ramsay signs for Harrogate Town from Premier League Southampton FC
Harrogate Town 0 Crawley Town 0: Sulphurites 'weren't sharp enough in final third'
Harrogate Town v Crawley Town: Sulphurites aiming to get back on track against toothless Red Devils
“I also don’t have the same motivation to train twice a day, six days a week anymore.
“I know that I’ll miss playing and I think that part of the reason I’ve carried on for the last couple of years was because I was sort of scared to finish, but the time has come.”
Dutch-born Duncalf, who splits her time between Harrogate and Brisbane, Australia, has enjoyed a stellar career, winning silver medals for England at the Commonwealth Games in both singles and doubles competitions in 2010 and 2014.
She has also won titles including the US Open, the Qatar Classic and the British National Championship during her 18 years as a professional, reaching the final of the World Open in 2011.
"I've loved playing squash, travelling the world and representing my country. There have been quite a few highlights," Duncalf added.
"Playing for England is something that I've always enjoyed, it was what I always wanted to achieve from being a little kid.
"Winning the National Championships for the first time in 2007 was special and when I won the 2010 Qatar Classic, that saw me become number two in the world.
"I held that ranking for quite a while and it's something I'm really proud of."
Duncalf, who is the women's president of the Professional Squash Association, says that she is looking forward to "not having to live out of a bag anymore" but will continue to work in the sport.
"I've been doing a little bit of coaching in Australia and will probably look to do more of that when I'm there," she added.
"I'm also the women's president of the PSA and do a lot of MCing at PSA events, trying to get the crowd going at tournaments and interviewing players when the come off court.
"This is a job that's much harder than being a squash player!"