Willers said he is relieved to have made the decision and keen to go out with a big result in Sweden this weekend.
"Even if I come out with a win here this weekend, I will cross the line happy with the decision."
Willers has battled with injury concerns for the last two years, coming back after surgery to compete strongly at the recent world championships but a third Olympics was not sufficient lure to continue.
"May be if it was this year but I definitely wouldn't have another year in me. BMX has been my life but as I get older I realise there are more aspects to my life."
Willers is a double world championship medallist, winning the bronze medal at Copenhagen in 2011 and the silver medal in Auckland in 2013. He has been placed in the top seven or better at the world championships on five occasions.
The Cambridge rider has competed in 15 World Championships and this weekend will be his 31st World Cup. He also competed in the sport's Olympic debut in Beijing where he was 15th and London where he was 16th.
He reached world number one in 2007 but his major run of form came in 2011, when he won the London World Cup test event, was the overall champion of the AMA BMX title in USA, was ranked number one in the world and dominated the world championship in Copenhagen.
Willers won every moto and elimination race to the grand final, where he led until he made the smallest of errors on one of the smallest of jumps with victory insight and the mistake saw him finish third.
Cycling New Zealand High Performance Director Mark Elliott said that Willers and Sarah Walker have played a vital part in the development of the sport in this country.
"Marc has paved the way for our high performance programme today, and the riders now in our programme would not have been there without him," Elliott said.
"Not only has he achieved much, but in a sport in its professional infancy, Marc has provided the benchmark of what it takes in terms of dedication to training and in the fortitude he showed to come back from serious injury. He will leave an indelible mark on BMX in this country."
Willers made a move to USA six years ago which proved the turning point in his career, living in southern California where he continues to train daily with a multitude of BMX stars.
"Moving to the US was the biggest thing in my life. It was needed to be done to make a career out of it. It was a change of life and the thrill of competition.
"I'm going to miss all of it but I would rather put in the same effort that I have done for the last 20 years in BMX into a new chapter and get the results."
Willers will remain living in California with his partner where he plans to return to his passion of custom cars, planning to establish a performance vehicle business.
