Calculating throw in meters

Hey guys.
So I know throw is calculated to when the lux drops to 0.25 lux and the calculation is the square route of ‘X’ when ‘X’=candela/0.25

However, say I wanted to calculate throw to 50 lux
Is as simple as candela/50 and then that answer square rooted or is it more complex than that?

Thanks
Thom

Yeah just replace the .25 with 50