Windows 10 file explorer unit confusion

Hi ghostanime2001,

I'm Dyari. Thanks for reaching out. I will be happy to assist you in this regard.

Actually, storage capacity is based on powers of 2. Thus, a kilobyte is actually 2^10 bytes which means 1 KB = 1024 bytes, and a megabyte is 2^20 bytes which means 1 MB = 1024 KB. This is referred to as a binary prefix.

However, in marketing, storage capacity is calculated based on powers of 10, so 1 KB is equal to 1,000 bytes, and 1 MB is equal to 1,000 KB. This is referred to as the decimal prefix.

You can get more information from the links below:

https://www.101computing.net/why-is-there-1024-...

https://www.dpreview.com/forums/post/39333932

https://pc.net/helpcenter/answers/why_1024_bytes

This leads to a difference in the values that you see.

Please let me know if you need further assistance and keep me updated.

____________________________________________________________

Standard Disclaimer: There are links to non-Microsoft websites. The pages appear to be providing accurate, safe information. Watch out for ads on the sites that may advertise products frequently classified as a PUP (Potentially Unwanted Products). Thoroughly research any product advertised on the sites before you decide to download and install it.

Hi ghostanime2001,

I'm Dyari. Thanks for reaching out. I will be happy to assist you in this regard.

Actually, storage capacity is based on powers of 2. Thus, a kilobyte is actually 2^10 bytes which means 1 KB = 1024 bytes, and a megabyte is 2^20 bytes which means 1 MB = 1024 KB. This is referred to as a binary prefix.

However, in marketing, storage capacity is calculated based on powers of 10, so 1 KB is equal to 1,000 bytes, and 1 MB is equal to 1,000 KB. This is referred to as the decimal prefix.

You can get more information from the links below:
https://www.101computing.net/why-is-there-1024-...
https://www.dpreview.com/forums/post/39333932
https://pc.net/helpcenter/answers/why_1024_bytes

This leads to a difference in the values that you see.

Please let me know if you need further assistance and keep me updated.

____________________________________________________________
Standard Disclaimer: There are links to non-Microsoft websites. The pages appear to be providing accurate, safe information. Watch out for ads on the sites that may advertise products frequently classified as a PUP (Potentially Unwanted Products). Thoroughly research any product advertised on the sites before you decide to download and install it.

This is confusing, so windows isn't actually based in KB as in file properties, all the file sizes are based on binary prefix instead?

I am sorry if I couldn't explain it well.

In Windows, KB represents 1,024 bytes, and MB represents 1,024 KB. This is because computers use a binary system to store data. As a result, when you convert a file size from bytes to KB, MB, or GB, the result will be slightly different from what you see in Windows.

For example, I have a folder, its size is 209 MB (219,529,216 bytes) (As shown in folder properties). If I convert 209 MB to bytes with a convertor, I get (219,152,384 bytes) not the same as shown in folder properties.

Please feel free to ask if you have more questions.

Have a nice day.

Unfortunately, the good folks at Microsoft decided (in a strangely confusing move) to abandon the standard, typical units, and re-defining what they mean. In the real world, there are 2 ways to measure bits/bytes, decimal and binary.

decimal:

KB (kilobyte) = 1000 Bytes

binary:

KiB (kibibyte) = 1024 Bytes

but for some reason, Microsoft decided to ignore this completely and incorrectly define a KB as 1024 bytes. I'm not sure why they felt the need to do this, since in any/every other context the prefix "kilo-" means 1000. One KILOgram is 1000 grams, one KILOmeter is 1000 meters, etc. Microsoft for some reason hasn't bothered to add an option (that I am aware of) to change this to the correct unit definition. Microsoft has done a fair bit of damage, misleading people, to the point where even moderately experienced users will mix up unit definitions, so I've included below a list of units and their real values as recognized by the NIST, IEEE, and the IEC.

Binary:

KiB = 2^10 = 1,024

MiB = 2^20 = 1,048,576

GiB = 2^30 = 1,073,741,824

TiB = 2^40 = 1,099,511,627,776

PiB = 2^50 = 1,125,899,906,842,624

Decimal:

KB = 10^3 = 1,000

MB = 10^6 =1,000,000

GB = 10^9 =1,000,000,000

TB = 10^12 =1,000,000,000,000

PB = 10^15 =1,000,000,000,000,000

For more in-depth information, you can refer to "IEC 60027-2: Letter Symbols to be Used in electrical technology - Part 2: Telecommunications and Electronics" which is the official documentation on the standard.