Video Resolution Calculator & Aspect Ratio Calculator

Use this video resolution calculator to choose a resolution, frame rate, duration, and codec, and this calculator gives you the estimated file size, bitrate, data per frame, and total frames — so you know exactly how much storage your footage will need.

Need a clip to fit a new frame without it looking stretched or squashed? This video resolution calculator takes the width and height you already have, locks their aspect ratio, and returns the exact other side for any new size, along with the reduced ratio, the pixel count and how much of a different screen turns into black bars. Run it before you export for widescreen players, vertical platforms or old TV-style playback, and the shape of your picture stays the way you shot it.

How the Video Resolution Calculator Finds the Missing Dimension

Every frame is a rectangle with a fixed shape, and the tool treats that shape as locked. You give it the size you have, and it does one of three jobs: Television producers and post-production editors check the safe area calculator before delivering graphics to broadcast networks.

1. Find the missing side: enter the original width and height, type one new width or one new height, and the calculator returns the other side so the frame keeps its aspect ratio.
2. Name the ratio: enter both sides and it reduces them to a ratio such as 16:9 or 4:3, plus the decimal form.
3. Convert to another shape: choose a target ratio and see how much to crop, or how much padding to add, to get there.

Once you lock the ratio, a change to the width forces the height to follow. That is exactly what the "maintain aspect ratio" checkbox in an editor's resize dialog does, and it is why you can scale proportionally without ever doing the division yourself. Every answer comes back in pixel dimensions, so you can paste the new video dimensions straight into the video size fields of an export preset and get correct playback on the first try.

How to Scale Proportionally: The Resize Formula

A proportional resize holds one number constant: width divided by height. Multiply the new side by the old ratio and you get the side you're missing:

$$\text{New height} = \text{New width} \times \frac{\text{Original height}}{\text{Original width}}$$

$$\text{New width} = \text{New height} \times \frac{\text{Original width}}{\text{Original height}}$$

Divide the new side by the old one and you get the size change as a single number, \(k = W_{new} \div W_{orig}\). Because both sides change by the same \(k\), the shape never moves. The only thing that can nudge it is rounding: a frame can't hold a fraction of a pixel, so the calculator rounds each side to a whole number, and on awkward sizes that rounding shifts the ratio very slightly.

Worked Example: Original Dimensions 2560×1440, New Width 1600

Say you have a screen recording at 2560×1440 and a page player that is 1600 px wide. Here is the run:

1. Enter 2560 as the width and 1440 as the height.
2. Type 1600 into the new width field.
3. The tool works out \(1600 \times 1440 \div 2560\) and shows a new height of 900.

Each side shrinks to 62.5% of its old length, yet the pixel count falls to 39.06%, because both sides shrink at once and the effect is squared (\(0.625^2 = 0.390625\)). That second number tells you far more about how much detail the smaller copy keeps than the first one does.

Reducing Width and Height to an Aspect Ratio or Custom Ratio

To name a shape, the calculator divides both sides by the largest number that goes into each of them. For 2560 and 1440 that number is 160, so \(2560 \div 160 = 16\) and \(1440 \div 160 = 9\): 16:9 in simplest form. The decimal version is just width ÷ height, here 1.778.

$$\text{Ratio} = \frac{W}{\gcd(W,H)} : \frac{H}{\gcd(W,H)}$$

Some camera sizes don't reduce neatly. A 2704×1520 frame only reduces to 169:95, which works out to 1.779, close enough to 16:9 that any player treats it as widescreen. When a custom ratio like that turns up, the decimal is the more useful thing to read, since it lines up directly against the 1.778 of true 16:9. The tool doubles as an aspect ratio finder for any pair you type, and the resolution & aspect ratio calculator view shows the pair and the decimal side by side so you can judge how close two proportions really are.

Common Aspect Ratio Presets for Video: 16:9 at 720, 1080p HD and 4K

Most of the preset resolutions in the tool's dropdown sit on 16:9, because HD TV, YouTube and nearly every desktop monitor standardised on that shape. Pick a preset and both boxes fill for you.

The DVD row is the odd one out: its stored aspect ratio is not the aspect ratio you see, a point covered in the anamorphic section below. Look at how the 16:9 rows grow. 3840×2160 doubles both sides of 1920×1080, so it holds exactly four times the pixels, which is why a 4K export takes so much longer than a 1080p one even though the ratio never changes.

Widescreen 21:9 and Cinema Ratios

Wider than 16:9 is where film lives. These are the shapes you will meet most:

• 1.85:1 – the flat theatrical ratio used for many US releases.
• 2.39:1 – modern scope, the widescreen format most big features use today.
• 2.35:1 – the older CinemaScope figure, still quoted on many film releases.
• 21:9 – the label on ultrawide monitors; a 3440×1440 panel actually works out to 2.39:1.
• 32:9 – super ultrawide gaming screens, two 16:9 panels side by side.
• 1.43:1 – IMAX film, much taller than any of the above.

Digital cinema masters follow the DCI container sizes, so a scope film usually ships at 4096×1716 and a flat one at 3996×2160, and a projector crops nothing as long as the file matches.

Vertical 9:16, Square 1:1 and Portrait 4:5 for Social Media

On phones held upright, a vertical clip fills the whole screen, which is why YouTube Shorts, TikTok, Instagram Reels and Stories all use 9:16, normally at 1080×1920. Feed posts on Instagram are 1:1 or 4:5; the taller 4:5 takes up more of the feed, so it tends to be the better pick. A YouTube thumbnail stays 16:9 even when the channel mostly posts Shorts. Tablets add one more wrinkle: many are close to 4:3, so a 16:9 clip shows thin black bars when you hold one sideways. Because every social media app crops previews to its own shape, check the aspect ratio of the preview as well as the full post, and keep faces away from the edges that phones and feeds trim first.

Photography and Monitor Ratios Built on 4:3

4:3 is the shape of old TV and early monitors (1600×1200 is a 4:3 monitor size), and Micro Four Thirds camera sensors still record it. Most stills cameras shoot 3:2 instead, and that difference bites when photography meets a video timeline. A 6000×4000 photo placed in a 16:9 frame either fits at 1620×1080 with bars on the sides, or gets cropped to 6000×3375, losing 15.6% of its height. The calculator gives you both numbers before you decide which compromise hurts less.

Fitting a Drone Clip to a 3:1 Lobby Wall: Working Out the Video Dimensions

An estate agency has a 5472×3078 drone flyover of a listing and wants it looping on the LED wall in their office lobby, which the installer's spec sheet lists as 3456×1152 pixels. The question I need answered before anyone exports: does the clip go on the wall letterboxed, or cropped to fill it?

I enter 5472 and 3078 first. The calculator reduces them to 16:9, so this is a standard widescreen source. Then I enter the wall as the target, 3456×1152, which reduces to 3:1. Two answers come back:

• Fit: the picture is limited by the wall's height, so it becomes 2048×1152, with 704 px of black on each side. That's 40.7% of a very expensive wall showing nothing.
• Fill: scaled to 3456 wide, the frame is 1944 tall, so 792 rows have to go. Back in source terms, I'm keeping a 5472×1824 band out of 3,078 rows, or 59.3% of the height.

I check the band by hand: 5472 ÷ 3 = 1824, which matches. The scale factor is 0.632, so this is a downscale, and both 3456 and 1152 divide by 16 (216 and 72), so the encoder gets clean blocks. I go with the fill. The house sits in the middle of the frame for the whole flight, so a centred 1824-row band loses sky and lawn, not the building.

Then I rerun with one input changed, because the installer mentioned a second wall at 3840×1080:

What stands out is that the two percentages always add up to 100%. The share of the source you keep by cropping is exactly the share of the wall that shows picture when you fit (16:9 ÷ the wall's shape). So the choice is never about how much you lose. It's about whether you lose it as black or as picture edges.

One caveat the video resolution calculator can't catch for you: many LED controllers take a 1920×1080 input and stretch it across the wall. If this one does, a 3456×1152 file gets squashed back down, so I ask the installer for the controller's input size before exporting anything. The agency's logo also goes inside the 2765×922 title-safe box, since the wall's bezel seams cut into the outer edge.

Anamorphic Video and the Pixel Aspect Ratio

Not every file has square pixels. The pixel aspect ratio (PAR) describes the shape of a single pixel, and the shape you see on screen is the stored shape multiplied by it:

$$\text{Display ratio} = \frac{W}{H} \times \text{PAR}$$

When PAR is 1, what you store is what you see. When it isn't, a pixel aspect ratio calculator is the only quick way to know the true display size.

Anamorphic Desqueeze Factors for Squeezed Footage

Anamorphic lenses squeeze a wider view sideways onto the camera sensor, and in post-production you stretch it back by the lens's desqueeze factor, usually 1.33x, 1.5x or 2x. The width multiplies by the factor; the height stays put.

• 3840×2160 shot through a 1.5x lens desqueezes to 5760×2160, a 2.67:1 picture. For a 3840-wide delivery, that becomes 3840×1440.
• A 1.33x lens on a 16:9 sensor lands at 2.36:1, very close to scope, which is why filmmakers pair the two so often.
• A 2x lens on a 4:3 sensor gives 2.67:1, which is then cropped to 2.39:1.

Enter the recorded size and the factor, and the tool gives you the desqueezed size before you set up the timeline, so you never end up editing in the wrong shape.

Correcting DVD and VHS Display Width

A DVD stores 720×480 (NTSC) or 720×576 (PAL) whatever the picture's real shape, so it looks squashed if you play it with square pixels. VHS captures land at the same sizes, and a VHS tape digitised without a fix shows the same squashed, slightly too-thin faces on playback. The fix is to work out the display width from the height and the intended ratio:

$$w = h \times r$$

• NTSC DVD at 4:3: \(480 \times 4/3 = 640\), so 640×480.
• NTSC DVD at 16:9: \(480 \times 16/9 = 853.3\), so 848×480 or 864×480 if you want a multiple of 16.
• PAL DVD at 16:9: \(576 \times 16/9 = 1024\) exactly, so 1024×576.
• A letterboxed DVD film: crop the bars first. With 360 picture rows at 2.35:1, the width is \(360 \times 2.35 = 846\).

That's what the width resize calculator does: height and ratio in, width out. The height resize calculator runs the other way, \(h = w \div r\). Blu-ray discs use square-pixel 1920×1080, so they rarely need either. If you do video editing on old tapes or DVD rips, crop first and resize second; resizing with the black bars still in place stretches the bars along with the picture, and the result still plays back squashed.

Who Uses a Resolution Converter for Video

Anyone who moves a picture from one screen to another needs the same few sums:

• Video editors setting up timelines and exports for several platforms from one master, including vertical cuts for phones and social media.
• Filmmakers and camera operators checking how a lens and sensor combination will desqueeze.
• Web developers sizing a video aspect ratio calculator result into a fluid layout so the player never letterboxes by accident.
• Designers making thumbnails, banners and title cards that line up with the safe areas.
• AV installers matching a projector image to a screen size, using a screen aspect ratio calculator to see whether 16:9 or 2.39:1 fits the wall.

The tool also gives a quick read on sharpness: a 27-inch 2560×1440 monitor works out to about 109 PPI, while the same size at 3840×2160 is about 163 PPI, so the same clip looks crisper on the second one, even though playback dimensions and aspect ratio are identical. Whichever devices you are targeting, the aspect calculator keeps every version you export the same shape.