Free tool
Aspect ratio calculator for video and images
This aspect ratio calculator works both ways.
Find the ratio
Type a width and a height.
Find the missing side
Type a ratio and one side.
Result
Worked example
A screen recording from a 1366 by 768 laptop, run through the calculator.
Ratio
683:384
1.779 to 1
Nearest common
16:9
Off by 0.05%
Video sizes at this ratio
- 854 × 480
- 1280 × 720
- 1920 × 1080
- 2562 × 1440
- 3842 × 2160
Rounded to even numbers, which H.264 video needs.
683:384 is 0.05% wider than 16:9, close enough that every player treats it as 16:9. At 1440 and 2160 lines the exact ratio lands two pixels wide of the standard sizes, so export at 2560×1440 or 3840×2160 instead.
Common ratios
- 16:91.7781280×720, 1920×1080, 3840×2160YouTube, slides, TV, most LMS players
- 9:160.563720×1280, 1080×1920Reels, Shorts, TikTok, Stories
- 4:31.333640×480, 1024×768, 1440×1080Older video, iPad screens, classroom projectors
- 1:111080×1080Square feed posts
- 4:50.81080×1350Portrait posts in the Instagram and LinkedIn feeds
- 21:92.3332560×1080, 3440×1440Ultrawide monitors, letterboxed film
- 3:21.51080×720, 6000×4000Photos from most DSLR and mirrorless cameras
Social video sizes
- YouTube16:9, 1920×10803840×2160 for 4K
- YouTube Shorts9:16, 1080×1920
- Instagram Reels9:16, 1080×1920
- TikTok9:16, 1080×1920
- Instagram feed4:5, 1080×13501:1, 1080×1080
- LinkedIn feed16:9, 1920×10801:1, 1080×10804:5, 1080×13509:16, 1080×1920
Have the video already? Resize a video to this, or crop it by hand.
1. Type a width and height. 2. Or a ratio and one side. 3. Check the platform sizes. 4. Resize your video.
What Interlace does
Pick the ratio. Every scene is laid out for it.
- Choose 16:9, 9:16 or 1:1 before the video is made
- Scenes are composed for that frame, so nothing is cropped later
- The same script in each shape you need
Real Interlace output, unedited. Shown silent and sped up.
Your sizes
1920 x 1080 16:9
1080 x 1920 9:16
1080 x 1080 1:1
Questions
Asked and answered
Divide the width and the height by the largest number that divides both. 1920 and 1080 are both divisible by 120, which leaves 16 and 9, so 1920 by 1080 is 16:9. The calculator does this for you and also shows the ratio as one decimal number, 1.778 for 16:9, which makes two ratios easy to compare.
Reduced, it is 683:384, or 1.7786 against 1.7778 for true 16:9. Many laptop screens use it, and it is close enough that everyone calls it 16:9. The calculator shows the exact ratio and names the nearest common one, so you can see both.
1080 by 1920 pixels is the size Instagram Reels, YouTube Shorts and TikTok ask for. 720 by 1280 is the same shape at a lower resolution, and some phones record 2160 by 3840.
Video encoded as H.264 with standard 4:2:0 colour needs an even width and height, and most encoders refuse or crop an odd one. The calculator rounds the missing side to the nearest even number when the video option is on.
Not quite. Ultrawide monitors at 2560 by 1080 are 64:27, which is 2.370, while 21:9 is 2.333. 3440 by 1440 is 43:18, or 2.389. The name is a marketing round number, which is why the table lists the real pixel sizes.
No. There is no file here at all. Every number is calculated by the page as you type.
Turn this into a video
Create an account and start from a document, script, or prompt.