The one rule behind every video size
Every video file obeys one multiplication. Size equals bitrate times duration, divided by eight to turn bits into bytes. The video file size calculator applies that rule with the audio track included: it adds your audio bitrate to the video bitrate, multiplies by the duration in seconds, and divides by eight. Nothing else hides inside a video file. Resolution, codec and frame rate matter only because each one moves the bitrate.
That single fact resolves most storage arguments. A 1080p label tells you the shape of the picture and nothing about its weight. Two files can share the label and sit ten times apart in size, because one came from a streaming preset at 8 Mbps and the other from a camera codec at 147 Mbps. Read the bitrate and you can weigh the file before it exists.
Recommended bitrates and the size of ten minutes
YouTube publishes recommended upload bitrates for standard dynamic range video, and the preset table in the tool uses those figures. The table below adds the size of a ten minute video at each setting, audio included at 320 kbps.
| Resolution | Recommended video bitrate | Size per 10 minutes |
|---|---|---|
| 2160p (4K) | 40 Mbps (range 35 to 45) | 3,024 MB, about 3.02 GB |
| 1440p | 16 Mbps | 1,224 MB, about 1.22 GB |
| 1080p | 8 Mbps | 624 MB, about 0.62 GB |
| 720p | 5 Mbps | 399 MB, about 0.40 GB |
| 480p | 2.5 Mbps | 212 MB, about 0.21 GB |
| 360p | 1 Mbps | 99 MB, about 0.10 GB |
The candles show why one resolution has no single size in the wild. Adaptive streaming serves a ladder of renditions, so the 1080p a viewer receives on a weak connection may carry half the bitrate of the 1080p file its creator uploaded. Upload numbers follow the platform table; delivered numbers follow the viewer's bandwidth.
Camera codec bitrates and gigabytes per hour
Camera and editing codecs run at far higher bitrates than delivery files, and Apple's published ProRes target rates make the gap concrete. The table below converts each 1080p target rate into gigabytes per hour.
| Codec at 1080p | Target bitrate | GB per hour |
|---|---|---|
| ProRes Proxy | 45 Mbps | 20.25 GB |
| ProRes 422 LT | 102 Mbps | 45.90 GB |
| ProRes 422 | 147 Mbps | 66.15 GB |
| ProRes 422 HQ | 220 Mbps | 99.00 GB |
Keep the last bar in view. Ten minutes of ProRes 422 weighs 11,025 MB, about eighteen times the ten minute YouTube 1080p file of the same lesson, the same slides and the same voice. Storage planning that starts from delivered sizes underbuys cards and drives by that same factor.
Worked examples
Ten minutes at the 1080p preset
The video bitrate is 8 Mbps and the audio adds 0.32 Mbps, for a total of 8.32 Mbps. Ten minutes holds 600 seconds, so the file carries 8.32 times 600, which is 4,992 megabits. Divided by eight, the result is 624 MB, or 0.62 GB. This is the reference answer the calculator gives for its own 1080p preset.
Thirty minutes at the 4K preset
The video bitrate is 40 Mbps, the audio adds 0.32, and thirty minutes holds 1,800 seconds. The total of 40.32 Mbps times 1,800 seconds gives 72,576 megabits, and divided by eight the file weighs 9,072 MB, or 9.07 GB. A half hour of 4K course footage therefore asks a drive for more room than fifteen half hours of 1080p.
Five minutes of ProRes 422
The camera preset runs at 147 Mbps with no audio track counted. Five minutes holds 300 seconds, so 147 times 300 gives 44,100 megabits, and divided by eight the clip weighs 5,512.5 MB, or 5.51 GB. A single short master clip outweighs an entire playlist of delivery files, which is the sentence every shared drive eventually teaches its owner.
MB, GB and why your drive disagrees
Two counting systems share the same letters, and the calculator shows both. Storage makers sell gigabytes in decimal: one GB holds 1,000 MB. Operating systems count gibibytes in binary: one GiB holds 1,024 MB, and the exact divisor between the two views of one file is 1,073.74 MB per GiB. A file of 9,072 MB therefore reads as 9.07 GB on the box it came from and as about 8.45 GiB on the computer that receives it. Nothing vanished; the ruler changed.
The per minute and per hour outputs in the tool exist for planning, not curiosity. Cards fill per minute, drives fill per hour, and uploads finish per connection speed. Enter your uplink speed beside the result and the tool converts the same file into waiting time, which is often the number a deadline actually cares about.
Common mistakes with exports and storage
Uploading the master as if it were the delivery file. A ProRes master is an editing asset. Platforms re-encode everything you send them, so the master buys no quality on the far side and costs hours on yours.
Asking for a bitrate you do not know. Most people know their resolution and their duration, not their bitrate. Start from the resolution preset, then adjust the bitrate only when a file's properties tell you its real rate.
Blaming the audio track. At 320 kbps, audio adds 144 MB per hour. A camera video track adds thousands. When a file misses a limit by a wide margin, the video bitrate holds the answer.
Ignoring variable bitrate at export. Two exports at the same nominal setting can land far apart when one uses constant bitrate and the other lets the encoder save bits on still scenes. A talking head simply does not contain 8 Mbps worth of motion in its quiet minutes.
Why I built this calculator
My day job is content and social media work for clients, and one client project taught me this arithmetic the expensive way. The project was two days from launching a course in Multan when the shared drive filled and the backups started failing. The videographer had exported ProRes masters, and I had been uploading and archiving those masters as if they were ordinary web files. One ten minute lesson video weighed more than 11 GB, and I had treated it as a normal upload for a week. The resolution was innocent. The export preset had been writing a cinema file for a phone screen, and nobody on the team, me included, could read a bitrate well enough to say so.
That night, on a support call with the editor, I learned the rule this page is built on: bitrate times duration, divided by eight. The fix took one evening. The masters went to an archive drive, the delivery exports went to the shared folder, and the launch went ahead. But I kept the notebook page where I had written the multiplication in pencil, because I knew I would need it again and would not remember it under pressure.
The calculators I found afterwards asked the one question I could not answer: they wanted a bitrate typed in before they would help. People do not carry bitrates in their heads; they carry resolution names and durations. Since that launch I read the bitrate line of every export before I look at its resolution, and I check each delivery copy against its master so the two never get archived as the same file again. This tool starts from the names people actually use, a 1080p upload, a ProRes export, a five minute clip, and only then shows the arithmetic. The guides below take the same approach to codecs, streaming and storage planning.
Guides on bitrates, codecs and storage
- Why a 10 minute 1080p video can be 600 MB or 11 GB
- H.264 vs H.265 vs AV1: the same video at half the size
- How much storage a wedding videographer needs for one season
- Live streaming bitrate: what your upload speed can actually carry
- 4K vs 1080p uploads: the real time and size difference
- How big is a one hour Zoom or Teams recording
- CBR vs VBR: why two exports with the same settings differ in size
- What the audio track adds: 320 kbps over a two hour video
- One minute of phone video at every setting: iPhone and Android sizes compared
- One master video, four deliveries: export sizes for YouTube, TikTok, WhatsApp and email
Questions people ask about this page
Why does the same video have a different size on different phones?
Phones record at different default bitrates, and many switch codecs without telling you. One phone writes H.264 at a full camera bitrate while another writes HEVC at roughly half the rate for a similar picture. The resolution label matches; the bitrate does not, and bitrate is what sets the size.
Why does a 64 GB card hold less than 64 GB of video?
Card makers count a gigabyte as 1,000 megabytes, and your computer counts a gibibyte as 1,024 megabytes. The card holds the same bytes either way; only the label changes. This calculator shows both figures, GB and GiB, so the gap stops looking like missing storage.
Does frame rate change the file size?
Yes, through bitrate. A 60 frames per second video carries twice the frames of a 30 frames per second video, and encoders raise the bitrate to hold quality, which raises the size. Platforms publish separate recommended bitrates for higher frame rates for exactly this reason.
How can I shrink a video file without recording it again?
Re-export it at a lower bitrate or with a newer codec. H.265 holds a similar picture at about half the H.264 bitrate, and AV1 goes lower again on supported platforms. Lowering the resolution shrinks the file fastest, but the bitrate change keeps the picture size and usually survives better on a big screen.
How much of a video file is the audio track?
Very little, in most cases. A 320 kbps stereo track adds 288 MB across a full two hours, while a 1080p video track at 8 Mbps adds 7,200 MB in the same time. When a file is too big, the video bitrate is the lever that matters.
Facts, checked against trusted sources
- YouTube publishes recommended upload bitrates for each resolution and frame rate in its support documentation, and the preset table on this page comes from that page. Source: YouTube Help, recommended upload encoding settings
- Apple publishes target bit rates for its ProRes codecs in the Apple ProRes White Paper, including 147 Mbps for ProRes 422 at 1080p, and the camera presets on this page use those figures. Source: Apple ProRes White Paper
