Aspect Ratio Calculator
Use our free aspect ratio calculator to stop guessing dimensions. Calculate the perfect width and height for any video or image so your content fits Instagram, YouTube, and monitors without getting stretched.
Calculator
Aspect Ratio
16:9
Dimensions: 1920 × 1080 px
Result
Enter values to see the calculation result
Common Presets
Video & TV
Cinema
Photography
Social Media
Displays
Why Does Ratio Matter?
Aspect ratio is just a fancy way of saying "the shape of the rectangle." It tells you how wide an image is compared to how tall it is. It's written as Width:Height (e.g., 16:9).
For example, a standard TV is 16:9. That means for every 16 units of width, it has 9 units of height. If you try to display a 4:3 image (like an old TV show) on it, you get black bars on the sides because the shapes don't match. Using the correct ratio ensures your content uses the full screen without being cropped or stretched.
Why Resolution is Different
Resolution refers to the actual number of pixels (e.g., 1920x1080), while aspect ratio describes the shape. You can have a tiny 16:9 image and a huge 16:9 image — they are the same shape, just different quality. This aspect ratio calculator helps you find the right resolution to match your desired shape.
Common Mistakes to Avoid:
- ×Stretching a 4:3 image to fit a 16:9 screen (makes people look short and wide)
- ×Uploading a horizontal video to TikTok (it will be tiny with huge black spaces)
- ✓The Fix: Use this calculator to find the exact pixel dimensions you need to crop or resize to.
Cheat Sheet: Common Ratios
16:9
📺Widescreen (YouTube/TV)
The standard for almost all modern video. Used by YouTube, Netflix, and TV broadcasts.
Popular Sizes:
1920×1080, 3840×2160 (4K)
9:16
📱Vertical (TikTok/Reels)
The mobile standard. If you are making a Story, Reel, or TikTok, use this.
Popular Sizes:
1080×1920, 720×1280
1:1
⬛Square (Instagram)
A perfect square. Used to be the only option on Instagram. Good for profile pics.
Popular Sizes:
1080×1080, 500×500
4:3
🖥️Classic / iPad
The old "box" TV shape. Also roughly the shape of an iPad screen.
Popular Sizes:
1024×768, 1600×1200
21:9
🎬Ultrawide
Super wide format used in movies and curved gaming monitors.
Popular Sizes:
2560×1080, 3440×1440
4:5
📷Portrait (Insta Feed)
Slightly taller than a square. Best for Instagram posts as it fills more screen.
Popular Sizes:
1080×1350
How to Use the Aspect Ratio Calculator
Pick a Preset
Choose 16:9, 4:3, etc. from the dropdown if you know it.
Enter One Number
Type the width OR height you have (e.g. 1920).
Get the Other
We instantly calculate the matching dimension.
Or Use Custom
Enter both dimensions to find out what ratio they are.
💡 Quick Tips for Creators
- →YouTube: Always use 16:9 (1920x1080). If you upload other ratios, YouTube adds black bars.
- →Instagram Stories/TikTok: Use 9:16 (1080x1920). It's just 16:9 turned sideways.
- →Instagram Posts: 4:5 (1080x1350) takes up the most screen space on a phone feed.
- →Resizing: Lock the aspect ratio in Photoshop/Canva so your image doesn't get squished.
Aspect Ratio Calculator — Pixels, Inches, CM & More
People look for an aspect ratio calculator online for many different jobs — video exports, prints, LED walls, and social posts. This page explains how our free aspect ratio calculator fits those searches and what to enter for the best result.
Aspect Ratio Calculator for Pixels
The most common need is an aspect ratio calculator for pixels: you know one side in pixels (e.g. 1920 wide) and need the other height for 16:9. Use the calculator above: pick a preset or enter W:H, then type width or height in pixels. The result shows the matching dimension so your export is never stretched.
Aspect Ratio Calculator from an Image
Searching for aspect ratio calculator from image usually means you want the ratio of an existing photo or frame. On Windows or Mac, open the file's properties or info panel to read width × height in pixels, then paste those two numbers into the calculator to see the simplified ratio (e.g. 1920×1080 → 16:9). You can also use our Image Resizer when you already know the target size.
Image Upload & Physical Units
If you looked for an aspect ratio calculator image upload, this tool works in the browser with numbers you already have: no file upload is required, which keeps your images private. For aspect ratio calculator inches or aspect ratio calculator cm, the math is the same as pixels — only the unit changes. Convert inches or centimeters to pixels using your print DPI (e.g. 300 DPI for print): width_px ≈ width_in × DPI. Then use those pixel values here. For rough stage layouts in feet, convert feet → inches first, then to pixels at your chosen DPI.
Aspect Ratio Calculator for LED Wall & Pro AV
For an aspect ratio calculator for LED wall installations, start from the wall's total resolution in pixels (cabinet columns × cabinet resolution) or the native content raster your processor expects. Enter that width and height to confirm the ratio matches your timeline (often 16:9 or custom widescreen). Extra pixels beyond the wall are handled by scaling; matching aspect ratio at source avoids stretched branding on venue displays.
ARC & Broadcast Notes
Teams sometimes search aspect ratio calculator ARC when checking active format or safe-area conversions between HD, UHD, and cinema rasters. Use the presets here to lock 16:9, 21:9, or DCI-style ratios, then derive pixel dimensions for your master timeline so graphics don't get cropped in distribution.
Frequently Asked Questions
What size should my YouTube video be?▼
YouTube videos should be 16:9. The best quality is 1920×1080 (1080p). You can also do 1280×720 (720p) or 3840×2160 (4K). They all share the same 16:9 shape.
How do I fix a stretched image?▼
An image looks stretched because you changed its width or height without changing the other one proportionally. Use this calculator: enter the original width/height, then enter the NEW width you want. It will tell you the correct new height to keep it looking normal.
What aspect ratio is best for Instagram?▼
For Posts, use 4:5 (1080×1350) because it takes up the most vertical space on a user's phone. For Stories and Reels, you MUST use 9:16 (1080×1920) or it will be cropped.
Is 1920x1080 the same as 16:9?▼
Yes! 1920×1080 is the resolution (number of pixels), and 16:9 is the aspect ratio (the shape). If you divide 1920 by 120 you get 16. If you divide 1080 by 120 you get 9.
What is the ratio for iPhone wallpapers?▼
Most modern smartphones (iPhones, Samsungs) are roughly 9:19.5 or 9:20. Using a 9:16 (1080×1920) image usually works fine, but might be zoomed in slightly.
How do I use an aspect ratio calculator for pixels?▼
Enter your known width or height in pixels in the calculator, choose the ratio (e.g. 16:9), and it returns the other dimension in pixels. That way exports stay sharp and undistorted.
How do I get aspect ratio from an image without uploading?▼
Check the image file properties for width and height in pixels. Type both values into the calculator to see the simplified aspect ratio. No upload is needed and nothing leaves your device.
Can I calculate aspect ratio in inches or centimeters?▼
Yes: convert your physical size to pixels using your print DPI (pixels ≈ inches × DPI), then use those numbers here. For centimeters, convert cm to inches first or use pixels per cm from your design software.
How do I plan aspect ratio for an LED wall?▼
Find the full pixel width and height of the wall (or of your content raster). Enter them to verify the ratio matches your video master. Matching aspect ratio at production time avoids stretched logos on the display.
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