轻图神器
支持图片压缩、裁剪拼图、去水印,免费图片处理小程序
轻影神器
一键去除短视频水印、压缩大小、格式互转小程序
Professional tool for calculating image aspect ratios and dimensions. Maintain proportions when resizing photos and videos with preset ratios for social media, web design, and print.
Enter original dimensions and click "Calculate Ratio" to see the aspect ratio.
Select a preset ratio or enter custom dimensions to calculate the resized dimensions.
| Ratio | Common Use | Example Resolutions | Decimal |
|---|---|---|---|
| 16:9 | HD Video, YouTube, Widescreen | 1920×1080, 1280×720, 3840×2160 | 1.778 |
| 9:16 | Vertical Video, TikTok, Stories | 1080×1920, 720×1280 | 0.563 |
| 4:3 | Standard TV, Old Monitors, iPad | 1024×768, 800×600, 640×480 | 1.333 |
| 3:2 | DSLR Cameras, Photo Prints | 3000×2000, 1800×1200 | 1.500 |
| 1:1 | Square, Instagram Posts | 1080×1080, 1200×1200 | 1.000 |
| 21:9 | Ultrawide Monitor, Cinema | 2560×1080, 3440×1440 | 2.333 |
| 5:4 | Old Monitors, Large Format | 1280×1024, 2560×2048 | 1.250 |
| 2:3 | Portrait Photos, Posters | 2000×3000, 1200×1800 | 0.667 |
| 3:4 | Tablet Portrait, Books | 1536×2048, 768×1024 | 0.750 |
| 4:5 | Instagram Portrait | 1080×1350, 1200×1500 | 0.800 |
支持图片压缩、裁剪拼图、去水印,免费图片处理小程序
一键去除短视频水印、压缩大小、格式互转小程序
You’re in the middle of editing a client’s social media banner. The original photo is 4000×6000 pixels, but the platform insists on a 16:9 crop. You need to resize it without losing the subject, and you don’t have Photoshop on this machine. The first thing you search for is an “image ratio calculator” – but you hesitate. Will the tool upload your image to some server? Is it safe for client work? What if it’s full of ads or requires a sign-up?
If that sounds familiar, you’re not alone. A good image ratio calculator should do one thing perfectly: help you maintain proportions when resizing photos and videos, without ever touching your original file. The one I’ve been using at heycalc.org is exactly that – fast, private, and surprisingly thorough. Let me show you why it’s become my go‑to for everything from YouTube thumbnails to print brochures.
Most online calculators either oversimplify (just a ratio box) or overcomplicate with sign‑up walls. The ideal tool lets you:
But more importantly, the best ones process everything inside your browser. No data travels to a server. That’s not just a privacy bonus – it means you can use it with confidential client files, medical diagrams, or any sensitive content without worrying about leaks.
I’ll walk you through two real‑world scenarios that map directly to the tool’s main tabs.
You’ve got a photo that’s 3000×2000 pixels. You need to know if it’s a standard 3:2 (DSLR print) or something else. In the Ratio Calculator tab, enter the width and height, click “Calculate Ratio”, and you instantly get:
This is invaluable when you’re batch‑prepping images for a print run and need to verify consistency. The “Load Example” button is a nice touch – it fills in typical 4K dimensions so you can see how the tool works in two seconds.
Say you’ve designed a square Instagram post (1:1) but need to adapt it for a Pinterest Pin (2:3 portrait). Switch to the Resize by Ratio tab. Pick “2:3” from the preset dropdown, then choose whether to lock the new width or height. The tool calculates the missing dimension, shows the scale factor, and even draws a visual comparison chart.
What I love: you don’t have to guess. If you lock width at 1000px, the tool gives you the exact height (1500px) and tells you the megapixels of the result. No mental math, no trial‑and‑error cropping.
I’ve tested half a dozen online image calculators over the years. Most of them either upload your image to a remote server (which is slow and risky) or run a clunky Java applet. This one does neither. Because all the calculation happens client‑side, you never see a progress bar or a “uploading” message. Even with a 50MB image, the ratio shows up instantly.
That “no upload” feature directly answers one of the most common concerns I hear from fellow freelancers: “Is an online image ratio calculator safe for client files?” Yes – because your file never leaves your computer. The tool only sees the numbers you type. It’s like using a physical calculator on your desk, but smarter.
This image ratio calculator excels at static images and videos where you need precise aspect ratios. It’s perfect for:
But if you need to batch‑rename files or apply watermarks, you’ll still need a dedicated photo editor. The tool is laser‑focused on ratio math – and that’s exactly what makes it reliable.
One of the most useful sections is the Common Ratios tab. It’s a quick‑reference table with:
I’ve bookmarked this page on my phone. When a client says “Can you make this fit our Twitter header?”, I don’t search specs – I just open this tab.
Just type the width and height in pixels into the Ratio Calculator tab. The tool processes the numbers locally in your browser – no file upload is needed. You’ll get the simplified ratio, decimal value, and percentage in less than a second.
Instagram feed posts work best at 1:1 (square) or 4:5 (portrait). Instagram Stories and TikTok both use 9:16. The Common Ratios tab in this calculator lists all the standard platform specs so you don’t have to memorize them.
Absolutely. The tool is fully responsive and works in mobile browsers without any app download. I’ve used it on an iPhone and an iPad to check dimensions while on the go – the touch inputs are smooth and the tabs are easy to tap.
Yes, it’s completely free with no sign‑up, no watermarks, and no daily usage caps. The only “ads” are standard display banners that support the site, and they don’t interfere with the calculator. You can calculate and resize as many images as you need.
Because this tool never uploads your images. All the math runs in your web browser using JavaScript. Your original files stay on your computer, and the numbers you enter are never sent to a server. This makes it safe for confidential client projects, medical images, or any private content.
YouTube recommends 16:9 for both videos and thumbnails. The most common thumbnail resolution is 1280×720. In the Resize by Ratio tab, select the 16:9 preset, lock the width at 1280, and the tool gives you the exact height of 720.