Pixel Aspect Ratio Calculator
Enter your stored resolution (actual pixel dimensions) and your intended display aspect ratio dimensions. The tool calculates pixel aspect ratio (PAR), storage aspect ratio (SAR), and display aspect ratio (DAR).
What is pixel aspect ratio?
Pixel aspect ratio (PAR) describes the shape of a single pixel in your image or video. If PAR is 1.0, pixels are square. If it is greater than 1.0, pixels are wider than they are tall. If it is less than 1.0, pixels are taller than they are wide.
This matters because a file can have one stored resolution but display correctly only when software applies the right pixel shape. If PAR is wrong, people can look stretched, circles can look like ovals, and graphics can appear distorted.
Three terms you should know
- SAR (Storage Aspect Ratio): Stored Width ÷ Stored Height.
- DAR (Display Aspect Ratio): Final intended on-screen width ÷ height.
- PAR (Pixel Aspect Ratio): DAR ÷ SAR.
Formula used by this calculator
We use the standard relationship between storage, display, and pixel shape:
Equivalent form:
This is the same formula used in video encoding, editing workflows, and broadcast conversion pipelines.
How to use this tool
- Enter your stored frame dimensions (for example, 720 × 480).
- Enter your target display ratio dimensions (for example, 16 and 9).
- Click Calculate PAR.
- Read the decimal value, simplified ratio, and interpretation.
If your output PAR is near 1.0000, your footage is effectively square-pixel. Otherwise, you are working with anamorphic or non-square-pixel content.
Common pixel aspect ratio examples
| Format | Stored Resolution | Display Aspect | Approx PAR |
|---|---|---|---|
| NTSC DV (4:3) | 720 × 480 | 4:3 | 0.9091 |
| NTSC DV Widescreen | 720 × 480 | 16:9 | 1.2121 |
| PAL DV (4:3) | 720 × 576 | 4:3 | 1.0667 |
| PAL DV Widescreen | 720 × 576 | 16:9 | 1.4222 |
| HD / UHD / Web Video | 1920 × 1080, 3840 × 2160 | 16:9 | 1.0000 |
Why PAR still matters
Even though most modern delivery formats use square pixels, pixel aspect ratio still appears in archives, legacy camera footage, broadcast ingest, DVD transfers, and some special conversion workflows. If you edit older assets, PAR is not optional knowledge.
Where you may see PAR issues
- Importing DV, D1, or SD broadcast files into modern NLEs.
- Converting between formats without explicit metadata.
- Round-tripping media between VFX, compositing, and editing tools.
- Encoding content for platforms with strict display rules.
Troubleshooting quick guide
- Image looks too wide: PAR is likely set too high.
- Image looks too tall/narrow: PAR is likely set too low.
- Graphics do not match video frame: Check both sequence DAR and clip PAR interpretation.
- Different apps show different shape: One app may be honoring metadata while another is ignoring it.
FAQ
Is PAR the same as resolution?
No. Resolution is pixel count (width × height). PAR is pixel shape. Two files can have the same resolution and still display differently if PAR differs.
What PAR should I use for web video?
For modern web delivery, use square pixels whenever possible: PAR = 1.0.
Can I convert non-square footage to square pixels?
Yes. You can rescale to a square-pixel frame while preserving display proportions. This is common when remastering archival media for modern platforms.
Bottom line
This pixel aspect ratio calculator gives you a fast, reliable way to align storage aspect ratio, display aspect ratio, and pixel shape. If your media ever looks stretched, calculate PAR first—it is often the root cause.