This video bitrate calculator turns any two of bitrate, duration and file size into the third. Give it a bitrate and a length and it returns the file size in MB and GB (and in the binary MiB and GiB that Windows shows), split into the video and audio shares, with the size per minute and per hour; give it a file size and a length and it returns the average bitrate, which is the figure a file's properties call "total bitrate"; give it a file size and a bitrate and it returns how long a recording fits, which is the question a memory card or a cloud quota asks. Under every result sits a table of the same duration at each bitrate Google recommends for YouTube uploads, so a planned video can be sized before it is exported, and a second box reads the size and length of a file you open and reports its real bitrate. Everything is arithmetic in your browser; no file is uploaded.
How to use the calculator
- Choose what to work out. File size from a bitrate and a duration is the usual case before an export or an upload; Bitrate from a file size and a duration tells you what an existing file was encoded at; Duration from a file size and a bitrate tells you how much footage fits on a card, in a quota or under YouTube's upload cap. The fields the mode does not need are hidden.
- Enter the figures. Duration as
1:23:45 (h:mm:ss), 12:34 (m:ss), 90 (a plain number is minutes), 90s or 1h30m. Video bitrate in Mbps or kbps; audio bitrate in kbps (128 is the usual stereo AAC figure, 384 is YouTube's recommendation, 0 for a silent file). File size in MB, GB, MiB, GiB, kB or TB; pick MiB or GiB when the number came from Windows Explorer.
- Read the result. The three figures (size, total bitrate, duration), then the video and audio shares, the size per minute and per hour, and the table of the same duration at YouTube's recommended upload bitrates. Copy link to this result gives a link to this page that reopens with the same inputs.
The arithmetic
A bitrate counts bits per second; a file size counts bytes, and a byte is eight bits. So size in bytes = bitrate in bits per second × duration in seconds ÷ 8, with the video and audio bitrates added together first, since a video file carries both streams. A 12 minute 34 second video (754 seconds) encoded at 8 Mbps with a 384 kbps stereo track is 8,000,000 × 754 ÷ 8 = 754,000,000 bytes of video and 384,000 × 754 ÷ 8 = 36,192,000 bytes of audio: 790.2 MB in all, 753.6 MiB. The container adds a little (headers, an index of where every frame starts, chapter and subtitle tracks), typically well under 1% for a long file, so the calculated figure is a few megabytes below the file on disk.
Two shortcuts cover most mental arithmetic. 1 Mbps for one hour is 450 MB (1,000,000 × 3,600 ÷ 8 = 450,000,000 bytes), so GB per hour is Mbps × 0.45: 8 Mbps is 3.6 GB an hour, 50 Mbps is 22.5 GB. And 1 kbps for one minute is 7.5 kB, so a 128 kbps audio track is 0.96 MB a minute and 57.6 MB an hour, a 320 kbps MP3 is 2.4 MB a minute and 144 MB an hour, and uncompressed CD audio at 1,411.2 kbps (44,100 samples × 16 bits × 2 channels) is 10.6 MB a minute and 635 MB an hour.
The reverse divides instead of multiplying: bitrate = bytes × 8 ÷ seconds. A 2 GB file that plays for 25 minutes was encoded at 2,000,000,000 × 8 ÷ 1,500 = 10,666,667 bits per second, 10.67 Mbps in all; with a 128 kbps audio track inside it, the video stream is 10.54 Mbps. And duration = bytes × 8 ÷ bitrate: a 32 GB card holds 32,000,000,000 × 8 ÷ 8,384,000 = 30,534 seconds, 8 hours 28 minutes, of 8 Mbps video with 384 kbps audio.
MB or MiB: why Windows shows a smaller number
Storage makers, macOS, most video software and this page use decimal units: a megabyte is 1,000,000 bytes and a gigabyte 1,000,000,000. Windows Explorer and a number of older tools divide by 1,024 instead (1,024 bytes to a KB, 1,024 of those to an MB, 1,024 of those to a GB) and still write "MB" and "GB", which the standards call mebibytes and gibibytes, MiB and GiB. The two drift apart by 4.9% at the megabyte and 7.4% at the gigabyte: 600,000,000 bytes is 600 MB and 572.2 MiB, and a "32 GB" card holds 32,000,000,000 bytes, which Windows reports as 29.8 GB. Nothing is missing; the units differ. Every result on this page gives both figures, and the file size field accepts MiB and GiB so a number copied from Explorer is read correctly.
YouTube's recommended upload bitrates
Google publishes recommended encoding settings for uploads: an MP4 container, H.264 video, AAC-LC (or Opus) audio at a 48 kHz sample rate, and the video bitrates below, which rise with resolution, with frame rate (48, 50 or 60 fps against 24, 25 or 30) and for HDR. The table shows the size of 10 minutes of video at each figure (video stream only; add the audio track from the column on the right of your result) and recalculates with the duration you enter above. The figures are Google's for the file you upload; YouTube re-encodes every upload into its own streams, so viewers never receive your bitrate, and a higher upload bitrate simply gives that re-encode a cleaner source.
| Resolution | SDR, 24/25/30 fps | Size of 10 min | SDR, 48/50/60 fps | Size of 10 min | HDR, 24/25/30 fps | Size of 10 min | HDR, 48/50/60 fps | Size of 10 min |
|---|
| 8K (4320p) | 80 to 160 Mbps | 6 to 12 GB | 120 to 240 Mbps | 9 to 18 GB | 100 to 200 Mbps | 7.5 to 15 GB | 150 to 300 Mbps | 11.25 to 22.5 GB |
| 2160p (4K) | 35 to 45 Mbps | 2.625 to 3.375 GB | 53 to 68 Mbps | 3.975 to 5.1 GB | 44 to 56 Mbps | 3.3 to 4.2 GB | 66 to 85 Mbps | 4.95 to 6.375 GB |
| 1440p (2K) | 16 Mbps | 1.2 GB | 24 Mbps | 1.8 GB | 20 Mbps | 1.5 GB | 30 Mbps | 2.25 GB |
| 1080p | 8 Mbps | 600 MB | 12 Mbps | 900 MB | 10 Mbps | 750 MB | 15 Mbps | 1.125 GB |
| 720p | 5 Mbps | 375 MB | 7.5 Mbps | 562.5 MB | 6.5 Mbps | 487.5 MB | 9.5 Mbps | 712.5 MB |
| 480p | 2.5 Mbps | 187.5 MB | 4 Mbps | 300 MB | not supported | – | not supported | – |
| 360p | 1 Mbps | 75 MB | 1.5 Mbps | 112.5 MB | not supported | – | not supported | – |
Audio: 128 kbps for mono, 384 kbps for stereo, 512 kbps for 5.1 surround; ten minutes of 384 kbps stereo is 28.8 MB, an hour 172.8 MB. Source: Google's recommended upload encoding settings, read 2026-10-07; Google revises the page, so check it before a large batch export. The upload cap is a separate limit: a file may be at most 256 GB or 12 hours, whichever is less (Google's upload limits page), and a 12-hour file stays under 256 GB only below 47.4 Mbps total, which 1080p at 8 Mbps clears by a wide margin while 2160p at 60 fps does not. The thumbnail has no bitrate at all; it is one image under 2 MB, and the thumbnail size page covers that cap.
Live streaming bitrates and the data they use
A live stream is a bitrate running for as long as the stream does, so the per-hour arithmetic above is the data a broadcast sends up. Google's live encoder settings page (read 2026-10-07) gives a minimum and a recommended video bitrate per resolution for H.264, with constant bitrate (CBR) encoding, a 2-second keyframe interval (never above 4) and 128 kbps AAC or MP3 stereo audio (384 kbps for 5.1). The upload data per hour at each figure:
| Live stream | Minimum video bitrate | Upload data per hour | Recommended video bitrate | Upload data per hour |
|---|
| 2160p (4K) at 60 fps | 14 Mbps | 6.3 GB | 50 Mbps | 22.5 GB |
| 2160p (4K) at 30 fps | 11 Mbps | 4.95 GB | 42 Mbps | 18.9 GB |
| 1440p at 60 fps | 8 Mbps | 3.6 GB | 34 Mbps | 15.3 GB |
| 1440p at 30 fps | 7 Mbps | 3.15 GB | 21 Mbps | 9.45 GB |
| 1080p at 60 fps | 6 Mbps | 2.7 GB | 17 Mbps | 7.65 GB |
| 1080p at 30 fps | 5 Mbps | 2.25 GB | 14 Mbps | 6.3 GB |
| 720p at 60 or 30 fps | 3 Mbps | 1.35 GB | 8 Mbps | 3.6 GB |
| 480p or 360p at 30 fps | 0.4 Mbps | 180 MB | 4 Mbps | 1.8 GB |
Add 57.6 MB an hour for the 128 kbps audio track. The same multiplication gives the download side: whatever bitrate a stream is delivered at, Mbps × 0.45 is the GB an hour it costs the viewer, and the Data per hour box above does it for any figure. The recommended live figures are higher than the upload figures for the same resolution because a live encoder has one pass and no time to spend bits carefully; a file export can afford a slower, two-pass encode that reaches the same quality at a lower bitrate.
Bitrate, resolution and quality
Resolution is the number of pixels in a frame (1,920 × 1,080 for 1080p, 3,840 × 2,160 for 2160p); bitrate is the number of bits per second the encoder spends describing those frames; frame rate is how many frames a second there are to describe. The file size follows the bitrate alone, which is why the calculator never asks for a resolution: a 1080p file at 4 Mbps is half the size of a 720p file at 8 Mbps. What the resolution changes is how much bitrate a clean picture needs. Four times the pixels (720p to 1440p, or 1080p to 2160p) and twice the frames (30 to 60 fps) both have to be paid for, which is why the recommended figures rise along both axes of the table above, and why a 4K file at a 1080p bitrate looks softer than the 1080p file would: the encoder spreads the same bits over four times the detail and throws most of it away.
Three more things move the quality a bitrate buys. The codec: H.265 (HEVC), VP9 and AV1 reach a given quality at a lower bitrate than H.264, so a file in one of those can be smaller than the table suggests and look as good, though YouTube's recommendation names H.264 for uploads. The content: static talking-head footage and screen recordings compress far better than sport, confetti, water or film grain, so the same bitrate is generous for one and starved for the other. And the rate control: a constant bitrate (CBR) file is exactly the size the calculator gives, while a variable bitrate (VBR) export aims at an average and lands near it, with the quiet passages lending bits to the busy ones; a quality-targeted export (CRF or a quality slider) has no fixed bitrate at all, and its size is only known afterwards, which is what the file-measurement box is for.
What the measurement box reads
When you open a file, the browser reports its size in bytes exactly, and its length if the browser can decode the container and at least one of its streams: MP4 and MOV with H.264 or AAC, WebM with VP8, VP9 or AV1, and plain audio files usually work; MKV, AVI, HEVC on some systems and camera-raw formats often give a size but no length, and the box then asks for the duration so the bitrate can still be worked out. The bitrate it reports is the average over the whole file, video plus audio plus container, which is the figure a file's properties dialog calls total bitrate; it does not separate the streams or read the codec. The file is opened with a local object URL and never leaves your device; nothing is uploaded, and closing the page discards it.
What the calculator does not do
It does not choose a bitrate for you: the YouTube table is Google's published recommendation and the only figures on this page that come from anyone but your inputs, and the right export bitrate for a given look depends on the codec, the content and the encoder settings, which the page cannot see. It does not read the bitrate of a stream from a URL or of a YouTube video, which is set by YouTube per playback resolution and not published per video. It does not convert, compress or re-encode anything; the file box reads two numbers and closes the file. And it does not account for the container overhead, chapter tracks or embedded subtitles beyond noting that they exist, nor for the second audio or video stream some files carry; for a file with several tracks, add their bitrates into the two fields.
Frequently asked questions
How do I calculate a video's file size from its bitrate?
File size in bytes = bitrate in bits per second × duration in seconds ÷ 8, because a bitrate counts bits and a file size counts bytes of eight bits each. Add the video and audio bitrates first. A 10-minute file at 8 Mbps video plus 128 kbps audio is 8,128,000 bits per second × 600 seconds ÷ 8 = 609,600,000 bytes, 609.6 MB (581 MiB). As a rule of thumb, 1 Mbps for one hour is 450 MB.
How big is a 10-minute 1080p video?
It depends on the bitrate, not the resolution. At YouTube's recommended upload bitrate for 1080p at 24 to 30 fps, 8 Mbps, ten minutes of video is 600 MB, plus 28.8 MB for a 384 kbps stereo track. At 12 Mbps (the 48 to 60 fps recommendation) it is 900 MB. A phone or a screen recorder writes 1080p at whatever bitrate it is set to, and the size follows that figure: at 3 Mbps the same ten minutes is 225 MB, at 50 Mbps it is 3.75 GB. The bitrate in the file's properties tells you which.
Why does Windows show a smaller file size than the calculator?
Windows Explorer and some other tools divide by 1,024 three times and still write GB and MB, so they report binary gibibytes and mebibytes. A file of 600,000,000 bytes is 600 MB in decimal units and 572.2 MiB in binary units, and Windows shows it as 572 MB. macOS Finder, storage card packaging and most video tools use decimal units. The calculator shows both so the number you see matches one of them.
What bitrate should I use to upload to YouTube?
Google's recommended upload encoding settings give, for SDR video at 24, 25 or 30 fps: 35 to 45 Mbps for 2160p, 16 Mbps for 1440p, 8 Mbps for 1080p, 5 Mbps for 720p, 2.5 Mbps for 480p and 1 Mbps for 360p, with higher figures at 48 to 60 fps (53 to 68, 24, 12, 7.5, 4 and 1.5 Mbps) and higher again for HDR. Audio: 128 kbps mono, 384 kbps stereo, 512 kbps 5.1, in an MP4 container with H.264 video. YouTube re-encodes every upload, so these are figures for a clean source, not what viewers receive.
What is the difference between bitrate and resolution?
Resolution is how many pixels each frame has (1920 × 1080 for 1080p); bitrate is how many bits per second the encoder spends describing those frames. The file size follows the bitrate alone: a 1080p file at 4 Mbps is half the size of a 720p file at 8 Mbps. A higher resolution needs a higher bitrate to look clean, which is why the recommended figures rise with resolution and with frame rate, but the resolution itself does not appear in the size arithmetic.
Does YouTube keep the bitrate I upload at?
No. Every upload is re-encoded into YouTube's own set of streams at each playback resolution, so the bitrate viewers receive is set by YouTube, not by your file. A higher upload bitrate gives that re-encoding a cleaner source and fewer compression artefacts to copy, which is why the recommended upload figures are higher than typical streaming bitrates. The thumbnail is separate again: it is an image file under 2 MB and has no bitrate.
How much data does a video stream use per hour?
Bitrate in Mbps × 0.45 gives GB per hour: 1 Mbps uses 450 MB an hour, 5 Mbps 2.25 GB, 8 Mbps 3.6 GB and 50 Mbps 22.5 GB. Google's live streaming encoder settings recommend 14 Mbps for 1080p at 30 fps (6.3 GB an hour of upload data) and 50 Mbps for 2160p at 60 fps (22.5 GB an hour), with minimums of 5 and 14 Mbps. The same arithmetic gives download data for watching: a stream delivered at 5 Mbps costs 2.25 GB an hour.
