---
title: "Scale Factor Calculator: Enlarge or Reduce by Ratio | MCC"
description: "Find the scale factor between an original and a new size, as a number, a ratio and a percent, and apply it to another length. Free and private."
url: "https://mcc-solutionsnj.com/tools/scale-factor-calculator"
---

Free tool

# Scale factor calculator

Enter the original size and the new size. The scale factor, the ratio and the percent change update as you type.

Original length

New length

Another length to scale (optional)

Run a small business, or do the books for one? Take the [free books check](/bookkeeping/health-check) or browse the [free Excel templates](/bookkeeping/templates). Want a hand? [Contact us](/contact).

Share

## Put this tool on your own site

Free to use. Paste this where you want it to appear. It runs in the visitor's browser, so nothing they enter is sent to us.

[See every calculator you can embed](/embed)

How it works

## How it works

The **scale factor is new size divided by original size**. Above 1 is an enlargement and below 1 is a reduction. Areas change by the scale factor squared, so doubling every length makes the area four times larger.

Example: a 4-inch photo enlarged to 10 inches has a scale factor of 10 / 4 = 2.5, a 150% increase, and its area grows 6.25 times. A 6-inch side on the same photo becomes 6 x 2.5 = 15 inches.

FAQ

## About this calculator

**How do I find a scale factor?**

Divide the new length by the original length. 10 divided by 4 is a scale factor of 2.5.

**What does a scale factor of 0.5 mean?**

Every length is half its original size, and the area is one quarter.

**How is a map scale written?**

As a ratio such as 1 : 24,000, meaning one unit on the map is 24,000 of the same units on the ground.

**Is anything saved?**

No. The math runs in your browser and nothing you enter is sent to us.

Related: [ratio calculator](/tools/ratio-calculator), [aspect ratio calculator](/tools/aspect-ratio-calculator), [golden ratio calculator](/tools/golden-ratio-calculator), [length converter](/tools/length-converter). See [all free tools](/free-tools). More free tools: [Standard deviation calculator](/tools/standard-deviation-calculator), [Paint calculator](/tools/paint-calculator), [Age calculator](/tools/age-calculator), or [see all free tools](/free-tools).

General information, not tax or legal advice. [How we write and check our tools](/editorial-standards).

Do it yourself

### Ratio and Proportion Worksheet Pack

About fifty original problems on printable pages, from writing a ratio to word problems, with every answer worked out in a separate key.

[See what's inside ($9)](/toolkits/ratio-proportion-worksheet-pack) [Free sample](/toolkits/ratio-proportion-worksheet-pack#free-starter)14-day full refund

## Need help with your business?

[Contact us](/contact)[Call (908) 444-6373](tel:+19084446373)