Oh, I should be able to do the math, but I've been pondering this for a while because some of the new kids on the block are using u100 compounded PZI. From the conversion chart : "U-100 will have 100 units per mL, and U-40 has 40 units per mL. This means that U-100 has 2.5 times the amount of active insulin per mL, therefore 2.5 times as strong. " So then, how does 1u of u100 PZI compare to 1u of u40 PZI? Is 1u of u100 PZI delivering more or less or the same amount of insulin as u40 PZI? Is it the same amount of insulin per unit, but u40 has more volume then u100? I don't mean to confuse things, but I've been trying to figure it out for a while.