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File Size Calculator

Estimate how big a media file will be. For video and compressed audio, multiply bitrate by duration; for uncompressed audio, use sample rate, bit depth and channels; for a raw image, use its pixel dimensions and color depth.

Quick examples
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File size600 MB
In mebibytes (1,024-based)
572.2 MiB
Data rate
8,000 kbps

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    Results you calculate here are kept on this device so you can come back to them.

      Formula

      Video or compressed audio: size in bytes = bitrate in bits per second × seconds ÷ 8
      Uncompressed audio: size in bytes = sample rate × bit depth × channels × seconds ÷ 8
      Uncompressed image: size in bytes = width × height × bits per pixel ÷ 8
      1 MB = 1,000,000 bytes; 1 MiB = 1,048,576 bytes

      How to use it

      1. Choose the type of file.
      2. Enter the bitrate and duration, or the audio or image settings.
      3. Read the size, and switch the unit to GB for long recordings.

      Worked examples

      10 minutes of video at 8 Mbps: 8,000,000 bits × 600 s ÷ 8 = 600 MB

      File size
      600 MB
      In mebibytes (1,024-based)
      572.2 MiB
      Data rate
      8,000 kbps

      A 3-minute stereo track as 44.1 kHz, 16-bit WAV: 31.75 MB

      File size
      31.75 MB
      In mebibytes (1,024-based)
      30.28 MiB
      Data rate
      1,411 kbps

      An uncompressed 1920 × 1080 image in 24-bit color: 6.22 MB

      File size
      6.22 MB
      In mebibytes (1,024-based)
      5.93 MiB

      Bits in, bytes out

      Bitrates are measured in bits per second, file sizes in bytes. Dividing by 8 is the step people forget: one minute at 8 Mbps is 8,000,000 × 60 ÷ 8 = 60,000,000 bytes, or 60 MB — not 480 MB.

      Handy reference points

      CD-quality audio (44.1 kHz, 16-bit, stereo) is 1,411 kbps, about 10.6 MB a minute uncompressed. A 128 kbps MP3 is just under 1 MB a minute. Video at 8 Mbps is 60 MB a minute, or 3.6 GB an hour.

      Compressed images are far smaller

      The image figure is the uncompressed size held in memory or saved as a plain bitmap. A JPEG, PNG or WebP of the same picture is usually a small fraction of it, by an amount that depends on the content and quality setting.

      Questions people ask

      How big is one hour of video at 8 Mbps?

      3.6 GB: 8,000,000 bits × 3,600 seconds ÷ 8 = 3,600,000,000 bytes.

      How big is a 3-minute WAV file?

      About 31.75 MB at CD quality (44.1 kHz, 16-bit, stereo).

      Why does my computer show a smaller number?

      Windows divides by 1,024 instead of 1,000 at each step but still writes “MB”. A 600 MB file shows as 572 MB. The mebibyte result gives that figure.

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