Image Resize Percentage Calculator

What this tool calculates

Calculate new image dimensions after resizing by a percentage. The main inputs on this page are Original width (px), Original height (px), Resize to (%). The result is intended to be readable immediately, with the explanation below available when you need to verify the method.

Method and calculation basis

For “X% of Y”, the method is Y × X ÷ 100. Percentage increase adds that amount to the starting value; percentage decrease subtracts it. Reverse-percentage calculations require division by the remaining or increased percentage rather than simply subtracting the rate.

Worked examples

Understanding the result

The output should be read in the units shown beside the result. If you are comparing alternatives, keep all unchanged assumptions identical and alter one input at a time. That makes it easier to see which value is responsible for the difference.

Assumptions, edge cases and accuracy

Dimensions and PPI are mathematical properties; they do not guarantee visual quality. Compression, resampling, focus and source quality still matter.

Sources and methodology

• W3C — Web image and browser standards where applicable
• Printer/image workflow documentation — PPI, dimensions and output-device requirements

Method reviewed for Instant Solvers V10.0 · October 2026. If you find a calculation or explanation that needs correcting, use the site Contact page and include the tool URL and the values you entered.