Aspect Ratio Calculator

Maintaining a consistent aspect ratio when resizing images, videos, or UI layout elements prevents distortion — stretched faces in profile photos, squashed video thumbnails, or incorrectly proportioned product images. The most common aspect ratios in digital media are 16:9 for widescreen video and monitors, 4:3 for standard definition content, 1:1 for Instagram posts and profile photos, and 9:16 for mobile vertical video. This calculator solves for the missing dimension: provide the original width and height plus the new width to get the mathematically correct new height, or vice versa. It also identifies the standard ratio name that matches any set of dimensions. Consider a web designer embedding a hero video that was filmed at 1920x1080 pixels but needs to fill a container only 740 pixels wide — entering those three values instantly returns the correct height of 416 pixels, keeping every frame perfectly proportioned. Or a photographer preparing a portfolio shot originally captured at 4500x3000 pixels for an e-commerce thumbnail slot that is 400 pixels wide; the tool outputs 267 pixels for the height, preventing the squashed look that damages product presentation. A social media manager repurposing a 1080x1080 square Instagram post into a 1280-pixel-wide Facebook cover image can verify the new height in seconds and avoid awkward cropping or stretching. Graphic designers, front-end developers, video editors, e-commerce managers, and content creators who regularly work across multiple platforms and screen formats benefit most from having a reliable ratio calculator at hand. Rather than reaching for a calculator and doing the cross-multiplication manually — or worse, eyeballing a resize and hoping it looks right — this tool provides an exact answer in a single step. All calculations run entirely in your browser, so no image or video file is ever uploaded to a server, making it safe to use with confidential client assets or proprietary media.