Aspect ratio calculator width, height, letterbox bars and a matte PNG.
Enter any two of width, height and aspect ratio and the calculator finds the third, with the format's name (16:9, 9:16, 4:5, 1.85:1, 2.39:1) and its common resolutions. It also shows the bar sizes when one ratio sits inside another frame and downloads a transparent matte PNG.
Free, no sign-upWidth, height and ratio
Fill in two fields and the third is calculated. Ratios can be 16:9, 16x9, 1.85 or 2.39:1.
- Simplified ratio
- As a decimal
- Format
- Orientation
Common resolutions
| Name | Width x height | Use |
|---|
Fit one ratio into another frame
See the bars (fit) or the crop (fill) when the picture's ratio differs from the frame.
Matte PNG
A transparent PNG at the frame size with only the bars. Put it on a track above the video in your editor.
Need the video in 9:16 without cutting off the speaker? We reframe it to follow them. Try it free
How to calculate a video's aspect ratio
- 01
Enter two values
Width and height to get the ratio, or the ratio and one side to get the other. The format buttons fill in the ratio for you.
- 02
See the format and resolutions
The calculator simplifies the ratio, names the format and lists its common resolutions. One click sends any resolution to the fields.
- 03
Fit it and download the matte
Pick the picture's ratio and your timeline frame to see the bars or the crop in pixels, then download the matte PNG for your editor.
How do I calculate height from an aspect ratio?
Divide the width by the ratio. At 16:9 the ratio is 16 ÷ 9 = 1.778, so 1920 ÷ 1.778 = 1080. To get the width, multiply the height by the ratio: 1080 x 1.778 = 1920. To find the ratio of a resolution, divide both sides by their greatest common divisor: 1920 x 1080 divided by 120 is 16:9.
When the math does not land on a whole number, the calculator rounds to the nearest even number, because most video codecs only accept even dimensions. A 2.39:1 picture 1920 wide, for example, would be 803.3 px tall; rounded, it becomes 804.
| Resolution | Ratio | Name | Common use |
|---|---|---|---|
| 1920 x 1080 | 16:9 | Full HD | YouTube, TV, standard timeline |
| 1080 x 1920 | 9:16 | Vertical | Reels, TikTok, Shorts |
| 1080 x 1350 | 4:5 | Portrait | Instagram feed |
| 1080 x 1080 | 1:1 | Square | Feed and ads |
| 3996 x 2160 | 1.85:1 | DCI 4K Flat | Cinema |
| 4096 x 1716 | 2.39:1 | DCI 4K Scope | Widescreen cinema |
What is the difference between 16:9, 1.85:1 and 2.39:1?
All three are landscape, and each is wider than the last. 16:9 (1.78:1) is the standard for TV, monitors and YouTube. 1.85:1, known as flat, is one of the two digital cinema (DCI) formats. 2.39:1, known as scope, is cinema widescreen; many people still call it 2.35:1, the older measure of the same format.
In cinema resolutions, full DCI 4K is 4096 x 2160 (about 1.90:1). Inside it, flat uses 3996 x 2160 and scope uses 4096 x 1716. Monitors sold as 21:9 sit between 2.37:1 and 2.39:1, practically the same shape as scope.
Aspect ratio describes the shape of the frame, not the quality. A 2.39:1 video at 1920 x 804 has fewer pixels than a 16:9 one at 1920 x 1080, even if it looks more cinematic.
How do I calculate letterbox bar size?
When a wider picture goes into a narrower frame, bands are left on top and at the bottom: that is letterboxing. The picture height is the frame width divided by the picture's ratio, and each bar is half of what is left. A 2.39:1 picture inside 1920 x 1080 ends up 803 px tall with bars of 138 and 139 px. The opposite, a narrower picture in a wider frame, leaves bands on the sides: pillarboxing, like 4:3 inside 16:9, with 240 px on each side.
Filling the frame instead of fitting removes the bars but crops the picture. A 16:9 video filling a 9:16 frame shows only about 32% of the original width; the rest falls outside, which is why framing matters so much in vertical video.
How do I use a cinema matte in my editor?
The matte is a PNG at the exact size of your timeline, transparent in the middle with the bars filled in. Download it, import it into Premiere, DaVinci Resolve or Final Cut and place it on a track above the video for the whole duration. You see the final shape while you frame, and you can move each shot within the open area.
100% opacity gives the final look; 80% or 50% lets you see what sits behind the bars, which helps while framing. If the video ships with bars, export with the matte; if it goes to a screen that already has the right shape, set the timeline straight to the final resolution.
More than an aspect ratio calculator. Your video comes out in each platform's format.
Frequently asked questions
What resolution is 16:9?
The most used are 1280 x 720 (HD), 1920 x 1080 (Full HD), 2560 x 1440 (QHD), 3840 x 2160 (4K UHD) and 7680 x 4320 (8K). They all share the same shape: the width is 1.778 times the height.
What resolution should a 9:16 video be for Reels and TikTok?
The standard is 1080 x 1920 pixels. There is also 720 x 1280, lighter, and 2160 x 3840 for vertical 4K. It is 16:9 turned on its side: the height is 1.778 times the width.
How do I find the aspect ratio of a resolution?
Divide the width and the height by their greatest common divisor. 1920 x 1080 becomes 16:9 and 1080 x 1350 becomes 4:5. Enter both values in the calculator and it shows the simplified ratio, the decimal and the format name.
Are 2.35:1 and 2.39:1 the same?
In practice, yes: both mean cinema widescreen. 2.35:1 is the older measure; today's projection standard is 2.39:1, often rounded to 2.40:1. At 1920 wide, the difference is a few pixels of height.
How do I add cinematic black bars to a video?
Choose 2.39:1 (or another ratio) and your timeline size, download the matte PNG and place it on a track above the video in your editor. The bars come out at the exact size, and you can nudge each shot up or down inside the open area.
Is the calculator free?
Yes. It is free, with no sign-up and no usage limit, mattes included.
From landscape to vertical without losing the speaker. In 9:16, 1:1 or 4:5.
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