720p vs 1080p vs 4K: video resolution explained

Resolution is the number of pixels in each frame. This guide explains what the labels mean, what else affects quality, and how much space each option takes.

Published October 5, 2026 · By the VideoDownGo team

Resolution labels such as 720p, 1080p and 4K describe how many pixels make up each frame of a video. More pixels can mean more detail, but only up to a point, and only if the rest of the chain keeps up: the camera, the compression, the screen and your eyes.

What the labels mean

YouTube publishes the dimensions it uses for standard 16:9 video in its resolution and aspect ratio help page:

360p: 640 × 360 pixels
480p: 854 × 480
720p (HD): 1280 × 720
1080p (Full HD): 1920 × 1080
1440p (2K): 2560 × 1440
2160p (4K): 3840 × 2160

The number in the label is the vertical pixel count. A 4K frame has four times as many pixels as a 1080p frame, and a 1080p frame has a little over twice as many as a 720p frame.

Vertical video, the format used by most short-video apps, simply turns the frame on its side. A common vertical size is 1080 × 1920. It has the same number of pixels as a 1080p landscape frame.

Resolution is not the whole story

Two videos with the same resolution can look very different. Three other factors matter.

Bitrate. This is how much data is spent on each second of video. A low bitrate forces the compression to throw away detail, which shows up as blocky patches or smeared motion. A 1080p video at a very low bitrate can look worse than a 720p video at a healthy one.
Codec. Newer codecs can deliver the same quality at a lower bitrate. See MP4 vs MOV vs WebM for the difference between containers and codecs.
Frame rate. Fast action looks smoother at 50 or 60 frames per second than at 24 or 30, but it needs more data. YouTube's recommended bitrates are higher for high frame rate content, by roughly one and a half times according to its upload encoding settings.

How big do the files get?

YouTube's recommended video bitrates for standard frame rate SDR uploads give a useful yardstick: about 5 Mbps for 720p, 8 Mbps for 1080p, 16 Mbps for 1440p and 35 to 45 Mbps for 4K. To turn a bitrate into a file size, divide by eight to get megabytes per second, then multiply by 60 for a minute of video.

720p at 5 Mbps: roughly 37 MB per minute, a little over 2 GB per hour.
1080p at 8 Mbps: roughly 60 MB per minute, about 3.6 GB per hour.
4K at 40 Mbps: roughly 300 MB per minute, about 18 GB per hour.

These figures ignore audio, which adds a little. Real files vary, especially when the video is already compressed by a social network, which often uses lower bitrates than the guidance above.

Which resolution do you need?

It depends on where the video will be watched.

Phone screens. 720p is often enough, and 1080p looks crisp. 4K is rarely noticeable on a small screen.
Laptops and desktop monitors. 1080p is a good default. Larger or sharper monitors benefit from 1440p or 4K.
Televisions. 1080p is fine for many rooms. 4K helps on large screens or when you sit close.
Editing. Shoot in the highest resolution you can store comfortably. It gives you room to crop and reframe, and you can export a smaller version for sharing.
Storage and bandwidth. If space or data is limited, 720p or 1080p with a sensible bitrate is a sensible compromise.

Upscaling does not add detail

Converting a 720p video to 1080p or 4K makes the file larger but does not create detail that was never captured. The software only stretches existing pixels. If you can, keep the video at its original resolution and let the player scale it.

Why a downloaded copy can look softer

When you upload a video, a platform usually re-encodes it to several sizes and bitrates so it plays on many connections. A copy you download later is one of those re-encoded versions, not your original. That is why it is worth keeping your own original file, as described in How to back up your own social media videos.

Quick reference

720p: small files, fine for phones and quick sharing.
1080p: the everyday default for most screens.
4K: best for large displays, editing and archives, at several times the storage.
Bitrate, codec and frame rate matter as much as the label.
Never rely on upscaling to improve quality.

Sources

Checked on October 5, 2026. Platform menus and policies change, so confirm details in the official pages.

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This guide is general information, not legal advice. VideoDownGo is an independent service and is not affiliated with the platforms mentioned.