calculator·Updated 2026-11-07

Recording File Size Calculator New

Turn a video and audio bitrate into file size, see how many hours fit on a drive, or find the bitrate that hits a target size. Built for OBS recordings and stream VODs, with multiple audio tracks and GB or GiB.

Client-side · CBR math + test-clip mode for VBR / CQP · GB or GiB

Bitrate · Length · File size

What do you want to calculate?

Video bitrate preset

Presets are YouTube's recommended upload bitrates (source, checked 2026-11-07), a reference for good-quality files, not OBS defaults.

Selected: YouTube upload rec. 1080p, 24–30 fps: 8 Mbps.

Video bitratewhat OBS records at

kbps

Audio tracks (1 of 6)

Track 1kbps

Quick-set track 1

Recording lengthhours

and minutes

min

Length slider (15-minute steps, up to 24 h)

Overhead (what-if)default 0

Units

Recording size

11.0 GB

3 h 00 min at 8,160 kbps (8.2 Mbps) total.

Per hour

3.67 GB

Per minute

61.2 MB

Total bitrate

8,160 kbps

Close for constant bitrate (CBR). VBR / CQP files follow the content, so use the test-clip tab for those. Container overhead is not included unless you set it.

Disk-space planner

Drive free space

Size unit

Hours per stream

Streams per week

/wk

Uses the bitrate from the calculator above (8,160 kbps total).

Hours that fit

272.3

Streams that fit

Weeks until full

22.7

Per stream

11.0 GB

Per week

44.1 GB

Per 30 days

189 GB

No sign-up required. Use the tool, share the result, leave — no account needed.

Client-side computation. Calculations run entirely in your browser; we never see your inputs.

Embed in OBS / Discord. Append ?embed=1 to the URL for a bare iframe-ready widget.

How to use the recording size calculator

Pick a mode. "File size" turns bitrate and length into gigabytes. "Time that fits" tells you how long you can record into a given amount of space. "Bitrate for a size" works backwards from a target file size (handy for upload limits). "From a test clip" measures the real bitrate of a short recording.
Enter the video bitrate you record at in OBS (Settings, Output, Recording), or click a preset.
Add every audio track you record. Each one is stored in full, so each adds to the size.
Set the length with the hour and minute fields or the slider.
Read the result, then scroll to the disk planner to see how many streams your drive holds.

The formula

Size in bytes = (video kbps + audio kbps) × 1000 ÷ 8 × seconds. Bitrate is measured in kilobits per second; dividing by 8 converts bits to bytes. The result is shown in GB (10⁹ bytes) or GiB (2³⁰ bytes). With constant bitrate (CBR) a real recording lands very close to this number. With variable bitrate or quality-based rate control it does not, which is why the test-clip mode exists.

GB per hour at YouTube's recommended upload bitrates

Video bitrates below are YouTube's recommended upload bitrates for SDR video (YouTube Help, checked 2026-11-07); for 4K, where YouTube gives a range, the low end is used. Sizes include your current audio tracks (160 kbps) and update when you change them.

Video bitrate	Size per hour	Hours on 1 TB
5,000 kbps	2.32 GB	430 h 39 min
7,500 kbps	3.45 GB	290 h 06 min
8,000 kbps	3.67 GB	272 h 19 min
12,000 kbps	5.47 GB	182 h 44 min
16,000 kbps	7.27 GB	137 h 30 min
24,000 kbps	10.9 GB	91 h 58 min
35,000 kbps	15.8 GB	63 h 12 min
53,000 kbps	23.9 GB	41 h 48 min

Click a preset to load it into the calculator. 1 TB = 10¹² bytes.

Recording bitrate vs streaming bitrate

A recording is written to your own disk, so it is not limited by upload speed or a platform's ingest cap. The live stream is. To pick a bitrate for going live on Twitch, Kick or YouTube, use our OBS bitrate calculator; if you record at the same bitrate you stream at, type that number here to see the VOD size.

OBS bitrate calculator: the stream bitrate that fits your upload and the platform limit.
Stream schedule generator: plan the streams the disk planner counts.
Donation fee calculator: what you keep from a tip after fees.

FAQ · methodology & caveats

Frequently asked.

Calculator outputs are estimates. Each Q below names the source data and the assumptions baked in.

How is recording file size calculated?

File size = (video bitrate + every audio track bitrate) × length in seconds ÷ 8. Bitrate is in kilobits per second, so 8,000 kbps of video plus 160 kbps of audio is 8,160 kbps, or 1,020 kilobytes every second. One hour is 3,600 seconds, which gives 3.67 GB (3.42 GiB). The calculator does exactly this, plus an optional overhead percentage if you want to pad the estimate.

How big is a one-hour 1080p60 recording?

It depends only on the bitrate you record at, not on the resolution label. At YouTube's published upload recommendation for 1080p at 48–60 fps (12 Mbps) plus one 160 kbps audio track, one hour is about 5.47 GB. At 8,000 kbps video it is about 3.67 GB. Click a preset or type your own OBS bitrate to see your number.

Why is my real file smaller (or bigger) than the estimate?

The formula gives a close estimate for constant bitrate (CBR). With VBR, CQP, CRF or OBS's quality-based presets the encoder spends fewer bits on simple scenes and more on busy ones, so the file size follows your content. For those modes use the "From a test clip" tab: record a few minutes of typical gameplay, type in the file size and its length, and the calculator projects any duration from the bitrate you actually got.

Does the calculator include container overhead (MKV / MP4)?

Only if you ask it to. Container headers and indexes add a small amount on top of the audio and video data, and the exact share depends on the container, muxer and stream count. We have not found an official figure for it, so the overhead field defaults to 0% and you can set your own what-if percentage to pad the estimate.

What is the difference between GB and GiB?

GB is decimal: 1 GB = 1,000,000,000 bytes, the unit drive makers print on the box. GiB is binary: 1 GiB = 1,073,741,824 bytes. The same file is about 7% fewer GiB than GB. Switch the unit toggle to match what your file manager shows.

How many hours of recording fit on a 1 TB drive?

At 8,000 kbps video plus 160 kbps audio, one hour takes 3.67 GB, so 1 TB (1,000 GB) holds about 272 hours. Use the disk planner below the calculator to enter your own drive size, how long you stream and how often: it shows how many streams fit and how many weeks until the drive is full.

Do multiple audio tracks make the file bigger?

Yes. Every audio track you record (for example game, mic and Discord on separate tracks) is stored in full, so each track's bitrate is added to the total. Add a row per track in the calculator to include them.

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