Video & Audio File Size Calculator

How to estimate media file size

1. Enter the duration and choose seconds, minutes or hours. For example, enter 1.5 hours instead of a timecode.
2. Enter a representative average bitrate and choose kbps or Mbps. For audio alone, use the total audio bitrate.
3. If the main rate excludes audio, turn on Add audio bitrate separately and enter that additional rate in kbps. Do not count audio twice.
4. Read the estimated decimal size. Open Calculation details for the binary equivalent and method, then copy the qualified summary if useful.

A focused size estimate from known rates

• Estimate video or audio data from duration and a supplied average bitrate without uploading a file.
• Add separately listed audio in kbps without manually mixing it with a video rate in Mbps.
• See one readable decimal size, with binary units and modeled bytes in details.
• Use decimal points or commas in separate fields, without digit grouping or a format selector.
• Keep sub-byte and rounded quantities qualified rather than showing false zero or an exact-file guarantee.

When the estimate is useful

• Plan an export when its duration and average encoding rates are known.
• Estimate a podcast or other audio recording from its supplied average audio bitrate.
• Check how changing duration or a known bitrate changes modeled media data, without assuming a codec's quality.

What duration and bitrate tell you

Bitrate describes bits per second. Multiplying an average rate by duration gives bits; dividing by eight gives bytes. For 3 minutes at 4 Mbps, the modeled size is 90 MB.

An overall bitrate may already include audio or other data. If the supplied rate is video only, separate audio can be added once. Any tracks or overhead absent from the entered rates are not invented by this calculator.

kbps and Mbps use decimal prefixes. They are not kB/s or MB/s: an uppercase B denotes bytes. A network plan's advertised speed is not the bitrate of your encoded recording.

Decimal MB and GB are different from binary MiB and GiB. The primary result uses decimal units; the same modeled quantity appears in binary units in details, without changing the underlying data.

For variable-rate encoding, use a suitable average rather than a peak. Resolution, codec name or a constant-quality setting alone does not specify a dependable size; this tool does not guess a bitrate from those settings.

Displayed size conversions have at most three decimal places. About marks actual conversion rounding, while the estimate qualification always applies. A modeled quantity below one byte stays positive and is not presented as zero stored bytes.

Video and audio size examples

A 3-minute recording at a combined 4 Mbps gives 90 MB before any data absent from that bitrate.

A 30-minute audio recording at 160 kbps gives 36 MB. No separate audio addition is needed when that is already the total audio rate.

For 12 minutes at 6 Mbps video plus 192 kbps audio, the total is 6.192 Mbps and the modeled size is 557.28 MB.

A modeled quantity of 1,000,000 bytes is 1 MB, but about 976.563 KiB. A quantity of 1,048,576 bytes is 1 MiB, but About 1.049 MB.

At the same representative bitrate, twice the duration gives twice the modeled data. This does not mean a different codec or quality setting must produce the same rate.

What this calculator cannot predict

Use positive duration up to 7 days and three decimal places per input. Main and combined rates are limited to 1000000000000 bits per second; additional audio is nonnegative. These are supported input bounds, not encoding recommendations.

The estimate depends on supplied rates. No automatic percentage is added for containers, metadata, subtitles, additional tracks or encoder variation. An overall supplied rate may already include some or all of them.

This is not a file inspector, encoder, compressor, speed test or upload-limit checker. It does not derive compressed size or quality from resolution, frame rate, codec, sample rate or bit depth.

An exact calculation from entered decimals is not a guarantee of an exact physical file size. Stored files have whole-byte sizes; fractional modeled bytes and display rounding are mathematical representations of the supplied average-rate estimate.

Your entries and copied summary

Calculation uses page memory, without file upload, account, saved input history or input-bearing share link. Copy happens only when requested.

The surrounding website can make ordinary requests under its existing consent and analytics settings. Local arithmetic is not whole-site privacy certification.