A scale factor is the number you multiply by to enlarge or reduce a figure. A factor greater than 1 enlarges, between 0 and 1 reduces, and every length changes by the same factor while the angles stay the same.
Math Dictionary / Scale Factor
Scale Factor
A scale factor is the number used to multiply side lengths when making a similar figure larger or smaller.
Ratios and ProportionsGrade 7Grade 8Algebra 1SATACT
What it means
It tells how much a figure is enlarged or reduced.
Also called: dilation factor
Examples
| A scale factor of 2 doubles every length |
| A scale factor of 1/2 makes lengths half as large |
| Scale drawings use scale factors |
Common mistake
A scale factor changes lengths, but area changes by the square of the scale factor.
Try one
Question: A side length 5 is enlarged by scale factor 3. What is the new length?
Show answer
15.