Incommensurable

1. (mathematics) Of two real numbers, such that their ratio is not a fraction of two integers.
2. (arithmetics) Of two integers, having no common integer divisor except 1.
3. Not able to be measured by the same standards as another term in the context.

Usage notes

The term contrasts with unmeasurable and immeasurable in that both mean "not able to be measured at all", with the latter generally being because of some infinite quality of the thing being described.