About the Scale Factor Calculator
Scale factor between two sizes, and how it affects length, area and volume.
Also known as: enlargement factor, reduction ratio, scaling calculator, similar figures scale.
How to use this calculator
- Enter i know, original area, original volume and the other fields.
- The result updates instantly as you type — press Calculate (or Enter) at any time.
- Review the breakdown shown under the main result.
- Use Copy result or Share to save the answer or send a link with your inputs.
Formula
k = new ÷ original · area scales by k², volume by k³
Worked example
Using the values pre-filled in the calculator above:
- I know: Two sizes
- Original size = 10
- New size = 25
- Original area = 50 m²
- Original volume = 30 m³
the calculator returns:
- Scale factor: 2.5 ×
- As a ratio: 2.5 : 1
- Area factor: 6.25 ×
- Volume factor: 15.625 ×