Home  Get your numbers right, and you'll be rewarded. Get it wrong, and you'll wonder if you're really such a bad driver! 

Here are some useful conversion factors for American standards
(foot/pound/second) to SI (MKS, meter/kilogram/second).
Note that Racer uses all SI units.
Name  S.I. Units  Equivalent units 
Force  N (Newton)  m.kg/s^2 
Power  W (Watt)  N.m/s, J/s, m^2.kg/s^3 
Torque  N.m  
Speed  m/s  
Acceleration  m/s^2  
Mass  kg  
Distance  m 
To go from  To  Multiply by  Divide by 
Moment of inertia lbs*ft^2  kg*m^2  0.042140110090  23.73036 
?Moment of inertia inlbs^2  kg*m^2  0.113  8.851 
?Moment of inertia ozinches^2  kg*m^2  0.007062  141.60 
Distances  to go from  To  Multiply by  Divide by 
Mile  km  1.6093  0.621388 
Foot (ft)  m  0.3048  
inch (in)  m  0.0254  
Mile  foot  5280  1.89393939 
Speed  to go from  To  Multiply by  Divide by 
km/h  m/s  0.2778  
mph  km/h  1.609  
mph  m/s  0.447  
Rotational speeds  to go from  To  Multiply by  Divide by 
1 rpm (revolution per minute)  rad/s  0.105  


Forces  to go from  To  Multiply by  Divide by 
1 G  m/s^2  9.8065  
lb (poundforce)  N  4.45  
lb (poundforce)  kg  0.4536 (assuming G=9.8)  
lb.ft (foot pounds)  Nm  1.356  
lb.ft/s (foot pound per second)  W  1.356  
hp (horsepower)  W  745.7 (500 ft.lb/s)  
metric hp (horsepower)  hp  0.986  
metric hp (horsepower)  kW  735.5  
Force/distance  to go from  To  Multiply by  Divide by 
lbf/in (poundforce per inch)  N/m  175.12685  0.00571 
Other links that might help:
(last updated November 13, 2012 )