Free tool · Video
Video Bitrate and File Size Calculator
Video file size in MB equals (video kbps + audio kbps) x seconds / 8000. Use the calculator below to run that formula in either direction: find the size a bitrate produces, the bitrate that fits an upload limit, or how long a clip can run. Audio is counted, YouTube presets are built in, and nothing leaves your browser.
Free, no account required.
Fills video and audio bitrate from YouTube's published upload settings.
8 Mbps is 8000 kbps.
Use 0 for a silent video.
Seconds (90), m:ss (1:30) or h:mm:ss (01:02:03).
Result
62.9 MB
62,880,000 bytes
Sizes use decimal units (1 MB = 1,000,000 bytes). Your operating system may show MiB, which is 1,048,576 bytes and reads about 4.6 percent smaller. Nothing you type leaves your browser.
The formula, worked through
Bitrate is bits per second, so file size is bitrate multiplied by time, converted from bits to bytes. Kilobits per second here means 1,000 bits, not 1,024, and a megabyte means 1,000,000 bytes.
Example. A 10 minute 1080p video at 8,000 kbps video and 384 kbps audio.
Total bitrate: 8,000 + 384 = 8,384 kbps. Duration: 600 seconds.
Size: 8,384 x 1,000 x 600 / 8 = 628,800,000 bytes, or 628.8 MB.
Going the other way, to fit 10 MB into a 60 second clip with 128 kbps audio and 2 percent overhead: 10,000,000 x 8 / 60 / 1,000 = 1,333 kbps total, minus 2 percent is 1,307, minus 128 leaves about 1,179 kbps for video.
YouTube recommended upload bitrates
These are the SDR video bitrates YouTube publishes for uploads, from YouTube Help: Recommended upload encoding settings, checked October 2026. YouTube re-encodes every upload, so treat them as upload targets. For 2160p Google gives a range, and the preset uses the low end. Google lists audio separately: 128 kbps mono, 384 kbps stereo, 512 kbps for 5.1.
| Preset | Video kbps | Audio kbps | MB per minute |
|---|---|---|---|
| YouTube 1080p, 24 to 30 fps (8 Mbps) | 8,000 | 384 | 62.9 |
| YouTube 1080p, 48 to 60 fps (12 Mbps) | 12,000 | 384 | 92.9 |
| YouTube 1440p, 24 to 30 fps (16 Mbps) | 16,000 | 384 | 122.9 |
| YouTube 1440p, 48 to 60 fps (24 Mbps) | 24,000 | 384 | 182.9 |
| YouTube 2160p, 24 to 30 fps (35 Mbps, low end of 35 to 45) | 35,000 | 384 | 265.4 |
| YouTube 2160p, 48 to 60 fps (53 Mbps, low end of 53 to 68) | 53,000 | 384 | 400.4 |
Source: https://support.google.com/youtube/answer/1722171. Checked October 2026.
Constant vs variable bitrate
Constant bitrate (CBR)
The encoder spends the same bits every second. File size lands very close to the calculator, which suits streaming to a fixed pipe and strict size limits. The cost is that simple scenes waste bits and busy scenes starve.
Variable bitrate (VBR)
The encoder spends more on complex scenes and less on simple ones, so quality is steadier at the same average. The bitrate you enter is an average, so real size drifts from the calculator. Leave headroom when a hard limit applies. YouTube Help (checked October 2026) lists variable bitrate and says no bitrate limit is required, with its recommended bitrates given for reference.
Picking a bitrate when there is a size limit
A size limit turns bitrate from a quality choice into a budget. The calculator's target-size mode gives you the budget; how you spend it depends on the encode mode.
Constant quality (CRF)
You choose a quality level, for example the crf option in ffmpeg with libx264, and the encoder uses whatever bitrate that needs. Best looking per byte, but the size is a result, not an input. Encode once, read the size, and adjust if you overshoot.
Two-pass target bitrate
You give the encoder the video bitrate from this calculator and it analyses the clip in a first pass, then distributes bits in a second. It is the reliable way to land near a hard limit such as an email or messaging upload cap.
Single-pass target bitrate
Faster, with the same input, but the encoder cannot look ahead, so quality is less even and the size drifts further from the figure. Fine for screen recordings, weaker for fast motion.
Audio bitrate, a short guide
Audio is a fixed cost per second, so it matters most on short, small files. YouTube Help (checked October 2026) lists 128 kbps for mono, 384 kbps for stereo and 512 kbps for 5.1 on uploads. When you are squeezing under a limit, a lower stereo figure is a trade-off you make yourself, not a platform recommendation, and speech survives it far better than music. Work out the video bitrate with the audio you intend to ship, because swapping audio afterwards changes the total.
Runs in your browser
This page does arithmetic on numbers you type. It does not ask for a video, it makes no network request when you calculate, and there is no account, watermark or usage cap. If you want to go further, see the other free tools or Linkeddit Studio.
How to calculate video file size from bitrate
Step 1
Pick what you want to find
Choose Size from bitrate, Bitrate for a target size, or Duration that fits. The fields change to match the question you are asking.
Step 2
Enter bitrate, duration or size
Type the video bitrate in kbps, the audio bitrate in kbps and the duration as seconds, m:ss or h:mm:ss. Or pick a YouTube preset to fill both bitrates.
Step 3
Read the result
The answer updates as you type. For a size limit, set the container overhead and use the video bitrate shown as the target in your encoder.
When you outgrow this tool
Linkeddit Studio exports H.264 MP4 at project size, 2160p, 1440p, 1080p, 720p or 480p, so you pick the quality tier once instead of doing this arithmetic per file.
This calculator is free and complete on its own, with no account. Linkeddit Studio is the desktop editor for the same job on files on your own disk: it exports H.264 MP4 with AAC audio at the project size, 2160p, 1440p, 1080p, 720p or 480p, with no watermark and no resolution cap, and a Claude Code or Codex agent can run the export for you. Studio is a one-time purchase.
FAQ
Video Bitrate and File Size Calculator questions
Direct answers on bitrate, file size, upload limits and the units that trip people up.
How do I calculate video file size from bitrate?
Add the video and audio bitrates in kilobits per second, multiply by the duration in seconds, then divide by 8 to get kilobytes, and by 1000 again for megabytes. In one line: size in MB = (video kbps + audio kbps) x seconds / 8000. A 60 second clip at 8000 kbps video and 384 kbps audio comes to 62.9 MB.
What bitrate should I use for 1080p YouTube?
YouTube Help (Recommended upload encoding settings, checked October 2026) recommends 8 Mbps for 1080p at 24, 25 or 30 fps and 12 Mbps at 48, 50 or 60 fps, for SDR video, and lists stereo audio at 384 kbps. The presets in this calculator use exactly those numbers; the source link is in the table below. These are recommendations for the upload, not a promise about what viewers receive.
How do I fit a video under a file size limit?
Switch to Bitrate for a target size, enter the limit in MB, the duration and your audio bitrate. The tool works out the total bitrate the limit allows, takes off container overhead and the audio, and gives you the video bitrate to set in your encoder. Use a two-pass or target-size encode mode so the encoder actually hits it.
Why is my exported file bigger than the calculator says?
Variable bitrate encoders treat your bitrate as an average, and a busy scene can push the file over the figure. Containers add metadata and index data, and extra tracks such as a second audio stream or embedded subtitles add more. Leave 2 to 5 percent of headroom when you are working against a hard limit.
What is the difference between MB and MiB?
A megabyte (MB) is 1,000,000 bytes. A mebibyte (MiB) is 1,048,576 bytes. Bitrates and most upload limits use decimal units, but some operating system file dialogs report MiB under the label MB, so the same file can look about 4.6 percent smaller there. This calculator uses decimal MB throughout.
Does the audio bitrate matter for file size?
Yes, and it is easy to forget. Stereo audio at 384 kbps, the figure YouTube Help lists for uploads (checked October 2026), adds roughly 2.9 MB per minute, which is a real share of a small file. For a tight size limit, lowering audio to 128 kbps frees bitrate for the picture. 128 kbps is YouTube's mono figure; for stereo it is a common size-limit trade-off rather than a platform recommendation.
What is the difference between constant and variable bitrate?
Constant bitrate (CBR) spends the same number of bits every second, which makes file size predictable. Variable bitrate (VBR) spends more on complex scenes and less on simple ones, which looks better at the same average but makes size less exact. YouTube Help (checked October 2026) lists variable bitrate and says no bitrate limit is required, with recommended bitrates given for reference.
Is my video uploaded when I use this calculator?
No. The calculator never asks for a video file. It is arithmetic on the numbers you type, it runs in your browser, and nothing is sent to Linkeddit or anywhere else.
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