The Enlargement Ratio Calculator helps determine how much larger an object becomes after scaling. It is commonly used in printing, photography, engineering, mapping, and model making. The calculator measures the ratio between the original and the enlarged version of a linear dimension or area. This calculator is part of the Scaling and Geometry Ratio Calculator category.
Whether you’re increasing the size of a photo, blueprint, or physical model, this tool allows you to calculate the exact enlargement ratio and ensure consistent proportions during scaling.
Formula of Enlargement Ratio Calculator
Enlargement Ratio = Enlarged Size / Original Size
Detailed Breakdown:
The enlargement ratio is a dimensionless value indicating how many times larger the new version is compared to the original.
There are two main use cases:
For Linear Dimensions (length, width, height, diameter):
Enlargement Ratio = Enlarged Length / Original Length
Use this when enlarging drawings, photographs, screen sizes, or any single linear measurement.
For Area Comparisons (e.g., photographs or floor plans):
Enlargement Ratio = √(Enlarged Area / Original Area)
This adjustment ensures the ratio reflects linear scale from area differences.
Quick Reference Table
Use this table to reference standard enlargement ratios and understand what they mean:
| Original Size (cm) | Enlarged Size (cm) | Enlargement Ratio |
|---|---|---|
| 5 | 10 | 2.0 |
| 10 | 15 | 1.5 |
| 20 | 60 | 3.0 |
| 7.5 | 30 | 4.0 |
| 12 | 36 | 3.0 |
These are for linear dimensions. If using area, take the square root of the area ratio to get the correct linear enlargement.
Example of Enlargement Ratio Calculator
Imagine enlarging a printed image that originally measures 6 cm in width to a new width of 18 cm.
Step 1:
Use the formula:
Enlargement Ratio = Enlarged Length / Original Length
Enlargement Ratio = 18 / 6 = 3
So, the enlargement ratio is 3, meaning the image is 3 times larger than the original.
For an area example, if the original photo covers 25 cm² and the enlarged one is 100 cm²:
Enlargement Ratio = √(100 / 25) = √4 = 2
This shows that each side is scaled by a factor of 2.
Most Common FAQs
It’s a value showing how many times larger the new version of an object is compared to the original, based on either length or area.
Yes. If the enlargement ratio is less than 1 (e.g., 0.5), it means the object is reduced by that factor.
Only if the enlargement is proportional. For non-uniform scaling (e.g., only height is changed), calculate each dimension separately.