Result will appear here.
Simplify image dimensions to a ratio and find matching sizes — 16:9, 4:3 and more, in your browser.
Simplifies width:height to lowest terms, shows the decimal ratio, orientation and common-ratio name.
Calculate by new width or by new height to find the matching dimension.
Inputs are checked as whole numbers within a safe range.
Computed from typed numbers; no image is read or uploaded.
Image Aspect Ratio Calculator simplifies an image's width and height to its lowest-terms aspect ratio, shows the decimal ratio and orientation, and names a common ratio such as 16:9, 4:3 or 1:1 when it matches. No image upload is needed — you type the dimensions.
Switch between calculating a new height from a new width or a new width from a new height, and the tool keeps the original ratio exactly. All inputs are validated as whole numbers within a safe range.
Everything is computed in your browser and can be downloaded as a small text summary.
Calculate a new height from a width, or a new width from a height, keeping the ratio.
Recognises 16:9, 4:3, 1:1, 3:2, 21:9 and more from the decimal ratio.
Whole-number range checks stop negative, decimal or absurd values.
Works entirely from typed dimensions, in your browser.
Find the matching dimension before resizing so nothing is stretched.
Confirm whether dimensions are 16:9, 21:9 or another standard ratio.
Work out target sizes for a specific ratio like 4:5 or 1:1.
Get exact ratios for grids, thumbnails and print sizes.
Yes. Set “Calculate by” to “New height → width”, type the new height, and it returns the width that keeps the original aspect ratio (and vice-versa).
Yes. When the decimal ratio matches a standard one such as 16:9, 4:3, 1:1, 3:2, 21:9, 4:5 or 9:16, that label is shown alongside the simplified ratio.
No. It works purely from the width and height you type, so it never uploads or reads an image file.
Width and height are validated as whole numbers within a safe range, so blank, negative, decimal or absurd values fall back to sensible defaults instead of producing broken ratios.
The width and height are divided by their greatest common divisor to express the ratio in lowest terms, e.g. 1920×1080 becomes 16:9.
Tools that pair well with Image Aspect Ratio Calculator.