Metropolitan Swimming: http://www.metroswimming.org/

USA Swimming:    http://www.usaswimming.org

NY YMCA Swimming:  https://www.gomotionapp.com/team/nyssc/page/home

YMCA National Swimming and Diving:  https://www.teamunify.com/team/yusa/page/home

Circle Swimming Calculator: http://www.swimmingworldmagazine.com/results/conversions.asp