Question: what is the difference between par 38 and r40?
Answer: The difference between a BR20, BR30, and BR40 is actually the size or diameter of the light bulb. ... For example, a BR30 is 30/8ths of an inch or 30 divided by 8 which equals 3.75″ in diameter. The same example applies to a PAR38. Divide 38/8ths of an inch or 38 divided by 8 which equals 4.75″ in diameter.