Boost ver: 1.45 Compiler: Visual Studio 2008 I am trying to figure out how to declare a plane angle to be dimensionless. In the code I have so far I am using: typedef boost::units::make_system<radii_base_unit, minute_base_unit, boost::units::angle::radian_base_unit >::type myproject_system_t; I have one velocity in radii^1.5/min and a second velocity in radian/min. When I divide the radii^1.5/min by radian/min I am expecting to see radii to be the final dimension. What I am seeing is the denominator has radians in it. Here is my equation ke = radii^1.5/min n = radian/min a1 = ( ke / n ) ^ (2/3) The 'min' dimension cancel out so I am left with radii^1.5/radian before applying the power of 2/3. Applying the power of 2 I see the units are radii^3/radian^2 and then the 1/3 to get a final of radii/radian^(2/3). According to the almighty Wikipedia the radian angle is a dimensionless term. I am wondering what is the recommended course of action I should be taking here? Stephen