# Is it correct that if an 8-inch diameter wheel was rotating at 1,000 RPM then the vehicle would be going 12 MPH?

I'm making an electric mountain board and I am trying to find what gear ratios work to get the speed I want. I don't know if my math is right and I was just checking.

active| newest | oldest- 2*pi*R //8*3.14= 25.12
- RPMS*25.12 //1000*25.12= 25120
- 60 minutes in a hour sooo... 25120*60= 1507200
- 12 inches in a foot sooo... 1507200/12= 125600
- 5820 feet in a mile (i think) so.... 125600/ 5820= 21.5807...

There we go!!