Math for
The Audio Video Professional
Advanced AV
Production Practicum
Calculating Audio and Video File Sizes
Copyright © Texas Education Agency, 2015. All rights reserved.
Calculating Single File Sizes
Objective:
Learn how to calculate the file
size of a Video Project to
determine if the costs of the
project will fall within budget
guidelines.
Copyright © Texas Education Agency, 2015. All rights reserved.
Calculating Single File Sizes
– Students Will –
 Calculate an assortment of file sizes
 Understand how file sizes change with
content and distribution method.
 Demonstrate knowledge of why file data is
manipulated
 Demonstrate proficiency with math
calculations
 Learn industry standard aspect ratios,
terms and formulas
Copyright © Texas Education Agency, 2015. All rights reserved.
Calculating Single File Sizes
What factors determine file size?
 Image Quality
– The larger the file size the better quality
 Distribution Method
– Broadcast, Stream, Download. Large files eat bandwidth
 Archive
– How much digital (disc) space is needed to archive
 Bit depth and sample size
(these are specific to Audio and Video files)
Copyright © Texas Education Agency, 2015. All rights reserved.
Calculating Single File Sizes
– Units of Measure –
 Bit – the smallest unit of data in a computer
 Byte = 8 bits
 Kilobyte (KB) = 1024 Bytes
 Megabyte (MB) = 1024 Kilobytes
 Gigabyte (GB) = 1024 Megabytes
Copyright © Texas Education Agency, 2015. All rights reserved.
Calculating Single File Sizes
– Units of Measure –
Conversion:
 Bit / 8 = Byte
 Byte / 1024 = Kilobyte (KB)
 Kilobyte (KB) / 1024 = Megabyte (MB)
 Megabyte (MB) / 1024 = Gigabyte (GB)
Copyright © Texas Education Agency, 2015. All rights reserved.
Calculating Single File Sizes
– Definitions –
Sample Rate
– The number of times a digital converter
samples the analogue source. Example:
 Audio - 44.1 kHZ,
 Video – 4:2:2 (color and luminance)
Copyright © Texas Education Agency, 2015. All rights reserved.
Calculating Single File Sizes
– Definitions –
Bit Depth
– The number of bits of information per sample.
 Audio – 16 bit
 Video – 8 bit uncompressed
Copyright © Texas Education Agency, 2015. All rights reserved.
Calculating Single File Sizes
– Video Formulas –
Total # of Frames =
Frame Rate x Duration of Video in Seconds
File Size of the Frame =
Horizontal Pixels x Vertical Pixels x Bit Depth / 8 x 1024
Total VIDEO File Size =
Total # of Frames x File Size of the Frame
Copyright © Texas Education Agency, 2015. All rights reserved.
Calculating Single File Sizes
– Audio Formulas –
Mono Audio File Size =
Sample Rate x Sample Size x Time in seconds
Stereo Audio File Size =
(Sample Rate x Sample Size x Time in seconds) x 2
Calculating Single File Sizes
– Total AV Formula –
Video File Size + Audio File Size =
Total Video File Size
Copyright © Texas Education Agency, 2015. All rights reserved.
Calculating Single File Sizes
– Example –
Example video is shot in 720x1080HD, 36 seconds in duration at 24
fps and a bit depth of 8-bit
Audio is Stereo 48K at 16bit
Step 1
Total # of Frames =
Frame Rate x Duration of Video in Seconds
Example:
Video has a duration of 36 seconds and shot at 24 fps
24fps x 36sec = 864 frames
Copyright © Texas Education Agency, 2015. All rights reserved.
Calculating Single File Sizes
– Example –
Example video is shot in 720x1080HD, 36 seconds in duration at 24
fps and a bit depth of 8-bit
Audio is Stereo 48K at 16-bit
Step 2
File Size of the Frame =
Horizontal Pixels x Vertical Pixels x Bit Depth / 8 x 1024
Example:
Video is formatted at HD 720 x 1080 at a bit depth of 24.
1080H x 720V x 8 = 6,220,800 = 759.375 KB
8 x 1024
8192
Copyright © Texas Education Agency, 2015. All rights reserved.
Calculating Single File Sizes
– Example –
Example Video is shot in 720x1080 HD, 36 seconds in
duration at 24 fps and a bit depth of 8-bit
Audio is Stereo 48K at 16bit
Step 3
Total VIDEO File Size =
Total # of Frames x File Size of the Frame
Example:
864 frames x 759.357 KB =
656,084.448KB or 640.707MB
Copyright © Texas Education Agency, 2015. All rights reserved.
Calculating Single File Sizes
– Example –
Example Video is shot in 720x1080 HD, 36 seconds in duration
at 24 fps and a bit depth of 8-bit
Audio is Stereo 48K at 16bit
Step 4
Total AUDIO File Size = Stereo Audio File Size =
(Sample Rate x Sample Size x Time) x 2
(48,000Hz x 16 bits x 36 seconds) x 2 = 27,648,000 bits
27,648,000 = 3,456,000 bytes 
8
3,456,000 = 3,375 KB 
1024
3,375 KB = 3.29 MB
1024
Copyright © Texas Education Agency, 2015. All rights reserved.
Calculating Single File Sizes
– Example –
Example Video is shot in 720x1080 HD, 36 seconds in
duration at 24 fps and a bit depth of 8-bit
Audio is Stereo 48K at 16bit
Step 5
Video File Size + Audio File Size =
Total Video File Size
(Video File Size – 640.707MB) + (Audio File Size – 3.29MB=
(Total File Size) 643.997MB
Copyright © Texas Education Agency, 2015. All rights reserved.
Calculating Single File Sizes
Your Turn!
Copyright © Texas Education Agency, 2015. All rights reserved.