gear ratio

[ralph@cloverleaf-auto.com]

I can not find my "auto math handbook" and I do not remember who I lent it
to. So..... does any one out there remember the formula for calculating
road speed? I know it is a combination of tire size, engine rpm, final gear
ratio, but I can not remember the exact formula. That's why I have the book
that I loaned to person{s} unremembered!

Thanks Ralph

1939 SS100 {that we are changing gears in}