I did my calculations using the ada specifications which calls for a 1:12 pitch the site was very helpful determining width and pitch and heighth of the railings size of landings etc. I'm thinking i'm gonna need some landings and curl it back to his fron sidewalk otherwise it'll be at least 36 foot long if his porch is 3 and a half foot off the ground
Being a wheelchair user. I can say the the pitch of the ramp will make a difference on how easy it is to push a chair up or down the ramp. some states have codes on ramps like NC does.