Aspect ratio calculator
Reduce a size to its ratio, or scale one dimension to a target ratio.
About this tool
Aspect ratio is the proportion between the width and height of a frame or print. Pick a common ratio or type in one dimension, and this tool returns the matching dimension and the simplified ratio. Use it to plan cropping, framing and print sizes so nothing important gets cut off at the edges.
How to use it
- Choose a preset ratio, or enter a width and height to derive one.
- Enter the known dimension you want to scale from.
- Read the matching dimension and the simplified aspect ratio.
FAQ
What aspect ratio does 35mm film use?
A full-frame 35mm negative is 36 by 24 millimetres, which simplifies to a 3:2 ratio. Many common print sizes such as 4x6 inches match this proportion closely.
Will changing the aspect ratio crop my image?
If the target ratio differs from your negative, some of the frame must be trimmed to fit. Leave a little breathing room around your subject when you shoot so you keep cropping flexibility later.