Written by the Fiveable Content Team • Last updated September 2025
Written by the Fiveable Content Team • Last updated September 2025
Definition
An order of magnitude is a class in a system of classification determined by size, typically measured in powers of ten. It is used to compare quantities by their relative scale.
5 Must Know Facts For Your Next Test
An order of magnitude represents a factor of ten change in quantity.
When comparing two quantities, if one is about ten times larger than the other, they differ by one order of magnitude.
In physics, orders of magnitude are commonly used to simplify and understand the vast range of physical quantities.
Orders of magnitude can be applied to both very large numbers (e.g., distance between stars) and very small numbers (e.g., atomic sizes).
$10^2$ and $10^3$ differ by one order of magnitude because $10^3 = 10 \times 10^2$.
A way to express very large or very small numbers using powers of ten. For example, $1.23 \times 10^6$.
Scale: The relative size or extent of something, often used to compare different physical quantities or phenomena.
Logarithm: The exponent that indicates the power to which a base number is raised to produce a given number. For example, if $b^y = x$, then $\log_b(x) = y$.