If you occasionally load and/or extract units of measure, but struggle to keep straight in your mind which value is the NUMERATOR and which is the DENOMINATOR, you are not alone. When you look the Material Master > Additional Data > Units of Measure screen you will see something like this.

You can easily hit F1 and find out that X = DENOMINATOR and Y = NUMERATOR, but I can’t tell you how many people have said to me “that always confuses me because, logically, I expect the first number to be the NUMERATOR.” Well here’s a quick and simple way to keep it straight in your head, which I believe will satisfy your desire to have it make logical sense.

If I said to you “express the variables A & B as a numerator / denominator ratio, most people immediately gravitate to:

A / B = NUMERATOR / DENOMINATOR.

Good… go with that. Now let A = Alt and B = Base (a logical extension, right?) and now you have:

Alt / Base = NUMERATOR / DENOMINATOR.

Now, simplly rearrange and you get:

DENOMINATOR x Alt = NUMERATOR x Base

which is exactly what you see in the Units of Measure screen. So there you go… simple… logical… and I’ll bet you never forget it now!