Video File Size Calculator
See how big your video will be before you upload it to WordPress. Enter the length and quality to get the size in MB and GB, and check it against your site's upload limit.
How the Video File Size Calculator Works
A video's size comes down to two numbers: its bitrate, which is how much data each second of video uses, and its length. The calculator adds the video and audio bitrates, multiplies by the length in seconds, and divides by 8 to turn bits into bytes.
File size = (video bitrate + audio bitrate) × seconds ÷ 8
For example, 10 minutes of 1080p at 8 Mbps with 128 kbps audio is 8.128 Mbps × 600 seconds ÷ 8 = 609.6 MB, which the calculator shows as 610 MB.
The WordPress check compares that size with the upload limit you pick. WordPress counts that limit in binary units, so a 128 MB limit is 134,217,728 bytes, and the calculator uses the same math.
Each resolution preset uses YouTube's recommended upload bitrate for H.264 video. For 4K, YouTube gives a range (35 to 45 Mbps, or 53 to 68 Mbps at high frame rates), so the calculator uses the middle of it. If you know the bitrate from your export settings, type it into the Video bitrate box and the estimate uses that instead.
Video File Sizes at a Glance
Here is how much space common lengths take at each resolution, at 24 to 30 fps with 128 kbps audio. High frame rate video (48 to 60 fps) uses the higher bitrate in the third column, so it takes about 50% more space.
| Resolution | Bitrate (24 to 30 fps) | Bitrate (48 to 60 fps) | 1 minute | 10 minutes | 1 hour |
|---|---|---|---|---|---|
| 4K (2160p) | 40 Mbps | 60 Mbps | 301 MB | 3.01 GB | 18.06 GB |
| 1440p (2K) | 16 Mbps | 24 Mbps | 121 MB | 1.21 GB | 7.26 GB |
| 1080p (Full HD) | 8 Mbps | 12 Mbps | 61 MB | 610 MB | 3.66 GB |
| 720p (HD) | 5 Mbps | 7.5 Mbps | 38 MB | 385 MB | 2.31 GB |
| 480p | 2.5 Mbps | 4 Mbps | 20 MB | 197 MB | 1.18 GB |
| 360p | 1 Mbps | 1.5 Mbps | 8.5 MB | 85 MB | 508 MB |
Frequently Asked Questions
How big is a 1-hour 1080p video?
About 3.66 GB at 8 Mbps, YouTube's recommended bitrate for 1080p at 24 to 30 fps, with 128 kbps audio. At 60 fps (12 Mbps) the same hour is about 5.46 GB.
How big is a 2-hour 1080p video file?
About 7.32 GB at 24 to 30 fps and about 10.92 GB at 48 to 60 fps, both with 128 kbps audio. A 2-hour 4K video at 30 fps is about 36.12 GB.
How many GB is a 20-minute video?
It depends on the resolution. At 24 to 30 fps with 128 kbps audio, 20 minutes is about 769 MB in 720p, 1.22 GB in 1080p, and 6.02 GB in 4K.
How big is 30 minutes of 1080p video?
About 1.83 GB at 8 Mbps with 128 kbps audio. At 60 fps it's about 2.73 GB.
How do you calculate video file size?
Add the video and audio bitrates, multiply by the length in seconds, and divide by 8 to get bytes. 10 minutes at 8 Mbps with 128 kbps audio is 8.128 Mbps × 600 ÷ 8 = 609.6 MB.
Why is my video a different size than the estimate?
Most exports use a variable bitrate, so busy scenes use more data and static ones use less. The codec matters too: H.265 (HEVC) and AV1 usually reach the same quality as H.264 at a lower bitrate. For the closest estimate, enter the bitrate from your export settings.
Why does Windows show a smaller number?
The calculator uses decimal units, where 1 GB is 1,000,000,000 bytes, the same as macOS and drive makers. Windows counts 1 GB as 1,073,741,824 bytes but still labels it GB, so the same file looks about 7% smaller there. The result shows both numbers.
How do I find my WordPress upload limit?
WordPress shows it as “Maximum upload file size” on the screen where you add new media. Your host sets it through the PHP settings upload_max_filesize and post_max_size, so raising it usually means asking your host or changing those settings.
Can I upload large videos to WordPress?
Only up to the maximum upload size your host sets, which WordPress shows on its upload screen, and many hosts cap it well below the size of a few minutes of 1080p. Videos also use up your hosting storage. Infinite Uploads Video Cloud lets you upload any size video from your WordPress dashboard, encodes it into multiple resolutions, and streams it in a clean, unbranded player.