An order of magnitude is the course of scale or magnitude of any amount, where each program includes values of a repaired ratio to the program anticipating it. In its most usual use, the amount being scaled is 10 and the scope is the (base 10) exponent being concerned this amount (subsequently, to be an order of magnitude greater is to be 10 times as substantial). Such differences in purchase of magnitude may be measured on the logarithmic scope in "ages" (i.e. variables of ten).

It is usual with experts and also technologists to state that a restriction whose value is not accurately understood, or is within a selection, is "of the order of" some value. For example, standby electrical power utilized in a home is not actually precisely recognized and changes in between households, however is usually of the order of a few tens of watts.