The Mira measures hormones in 'mu' (?)which is a u with a longer straight line on the left side. I think it means 40 or a millionth, depending what you read on Google! I haven't used the Mira for a while and I've forgotten, if I ever knew, how to translate it into pg/mL. But the Mira seems like a good idea, enabling you to test your own urine for progesterone and oestrogen at home.