# A word to indicate the ideal value between 2 other values (upper/lower)

Edit: This is related to a production process where a max value cannot be exceeded, and cannot be less than the minimum. There is then an 'optimal' value, which is a term suggested in the comments by John Lawler

For example, if the upper/lower limits are 3.5 and 3.0, the ideal middle value would be 3.25.

Is there a term for this 'middle value'?

• For some reason the word 'nominal' came to my head but that appears to be wrong. – pay Sep 13 '16 at 20:14
• That's the arithmetic mean (a + z) / 2, and with only two values it's also the median. If there's no other reason for its idealness, you can call it either one. If there are other reasons, you could refer to it as optimum or optimax, depending. – John Lawler Sep 13 '16 at 20:21
• Yes it is not simply a mean, it is related to a production process where there is an upper and lower limit, and an 'optimum' value as you have stated. – pay Sep 13 '16 at 20:21
• @pay nominal is correct in certain contexts. If I need to drill a pilot hole 0.202 +/- 0.001 inches, 0.202 is the nominal dimension. – Phil Sweet Sep 13 '16 at 20:51
• @PhilSweet Oh thanks for that, so I'm not completely crazy! This does refer to a measurement of an object that is quite small (the end of a wire, sort of). Do you think that would still apply? – pay Sep 13 '16 at 20:52

Aimed-for output from a process, or result from a measurement.

This has the advantage of not necessarily being the arithmetic mean or median, but rather an identified "number to shoot for". In some processes there might be more tolerance below the target than above or vice versa.

• This is the answer (IMHO). – Drew Sep 13 '16 at 20:48
• I'll likely use 'target value', 'optimal', or 'nominal', thanks. – pay Sep 14 '16 at 12:34

In some profession and skills, such as metalworking and engineering, the word "tolerance" is used for the minimum and maximum values when those values are stated with respect to the desired defined value. For example, a particular dimension may be given as .250 investment with a tolerance of .0005 inches, so that the minimum value is .2495 inches, and the maximum value is .2505 inches. In such places, .250 would be the "specified value".

This is often stated as,".250 plus or minus .0005 inches", and in writing, the "plus or minus" is often replaced with a character created with a plus sign and a minus sign in the same space, with the hype of the minus sign below the.plus sign.

• This is a possible option as well. I could switch the format slightly to having the focus be primarily on the optimal value with an upper and lower tolerance range. – pay Sep 13 '16 at 20:53

Consider rated value.

For example:

• Deviations of the mains voltage from the rated value must not exceed the tolerance limits given in the specifications.
• To obtain increased capacity and efficiency, the screw compressor is operated at a speed greater than its rated speed.

It's the midpoint of your target range or interval or optimal range or whatever.