Need to scale a resolution while preserving the aspect ratio? This tool handles it.
No installs, no registration, just open the mouse DPI tester and get accurate results in seconds.
Wrong dimensions ruin good content before anyone sees it. A mismatched crop on an Instagram portrait wastes screen real estate, and an incorrectly exported YouTube video looks broken the moment it goes live. DPI Analyzer’s aspect ratio calculator removes that risk entirely. Type in one dimension, pick a ratio, and get the exact matching value in real time.
No formula to memorize, no exports to redo. You get pixel-perfect results the moment you type.
An aspect ratio calculator takes one known dimension, either width or height, and returns the other based on a fixed ratio. Ratios like 16:9, 4:5, 1:1, and 21:9 define the proportional relationship between those two values. When you calculate aspect ratio with this tool, it handles all standard formats and any custom ratio you input. Hence, your output always matches the platform, screen, or print spec you’re targeting.
Here, how do you calculate aspect ratio by using the DPI Analyzer’s tool:
The 4:5 ratio is the tallest format Instagram permits in feed posts, which means it takes up more phone screen space than any other feed ratio. That extra vertical height is why portrait content consistently outperforms square posts in reach and visibility. Before you export, use this calculator to lock in the right dimensions.
Common 4:5 dimensions:
Beyond Instagram, the 4:5 ratio applies directly to Pinterest pins and any portrait-oriented content where vertical screen dominance matters.
16:9 is the universal standard for YouTube, Netflix, broadcast television, and nearly every monitor in production today. If you work in video, this is the ratio you’ll export at most often. The 16 × 9 aspect ratio calculator on this page covers every common resolution in this format, from basic HD to 8K.
Common 16:9 resolutions:
Before you spend money on a new monitor or build a multi-display rig, use the display ratio calculator to understand exact screen dimensions and proportional coverage. Each ratio suits a different workflow, and knowing that before you buy prevents a costly mismatch between your work and your screen.
Popular display ratios and where they fit:
Yes, completely free. No account creation, no subscription tier, and no usage cap. Open the tool, enter your values, and get your result immediately.
The 4:5 ratio is the tallest format Instagram allows in feed posts. It fills more of a phone screen than any other feed ratio and is standard for portrait photography and Pinterest content.
16:9 is the standard format for YouTube videos, television broadcasts, streaming platforms, and most monitors. It's the most widely used video and display ratio in the world.
You enter a known width or height, select a target ratio, and the calculator applies the ratio relationship to return the missing dimension, keeping your proportions mathematically exact.
16:9 is the dominant display ratio globally. The majority of monitors, laptops, televisions, and online video content all use it as the default standard.
Yes. Enter any ratio, including non-standard formats like 2.39:1, 17:9, or print-specific values, and the tool returns exact dimensions based on your input.
An incorrect ratio causes cropping, letterboxing, or visible distortion. The right ratio keeps your content sharp, properly framed, and platform-ready from the first export.