Use this useful tool to convert luminance choosing one of the 21 units of measurment included in this app (with the availability to add custom units), that are:
candela/square, meter, candela/square centimeter, candela/square foot, candela/square inch, kilocandela/square meter, stilb, , lumen/square meter/steradian, lumen/square centimeter/steradian, lumen/square foot/steradian, watt/sq. cm/steradian (at 555 nm), nit, millinit, lambert, millilambert, apostilb, blondel, skot, bril.