Why 1 Kilobyte Should Be 1000 Bytes, Not 1024

When we think about computer memory, most of us learned that a kilobyte equals 1024 bytes, a megabyte equals 1024 kilobytes, and so on. This binary-based system has been the standard for decades. But what if I told you that this convention, while practical, isn't technically correct—and that using 1000 bytes per kilobyte actually makes more sense?

The Binary Origins

The reason we often say 1 kilobyte = 1024 bytes comes down to how computers work. Computers operate in binary (base 2), and memory is addressed in binary as well. It's impractical to use memory addresses or produce RAM sticks with amounts that aren't multiples of powers of 2.

From the powers of 2, 1024 (2^10) was chosen as the base order of magnitude because it's very close to 1000 (only 2.4% difference) and isn't an insanely large number. So in practice, we've conventionally used kilo as 1024, mega as 1048576 (1024^2), giga as 1073741824 (1024^3), and so on.

The Growing Problem with Binary Units

While binary kilo, mega, and giga units are close to their decimal counterparts, there's a fundamental issue: the larger the units become, the more the proportional inaccuracy grows.

Let's look at the numbers:

Unit	Decimal value	Binary value	Relative difference
Kilo	1000	1024	2.4%
Mega	1000000	1048576	≈ 4.8%
Giga	1000000000	1073741824	≈ 7.3%
Tera	1000000000000	1099511627776	≈ 10%
Peta	10^15	~ 1.126 * 10^15	≈ 12.6%
Exa	10^18	~ 1.153 * 10^18	≈ 15.3%
Zetta	10^21	~ 1.181 * 10^21	≈ 18.1%
Yotta	10^24	~ 1.209 * 10^24	≈ 20.9%
Ronna	10^27	~ 1.238 * 10^27	≈ 23.8%
Quetta	10^30	~ 1.268 * 10^30	≈ 26.8%

For a 1 quettabyte (the largest standard unit), the inaccuracy is already larger than a quarter. Even for 1 terabyte, the difference is noticeable at around 10%.

This discrepancy often causes real-world confusion when hardware manufacturers (like HDD or SSD vendors) advertise memory capacity using decimal units while operating systems might display it using binary units. The result? That "missing 70 gigabytes" you notice when you buy a new drive isn't actually missing—it's just a difference in how the capacity is measured.

The Standard Solution

The "kilobyte = 1024 bytes" rule is actually an old convention that has created significant confusion in the tech industry. While RAM manufacturers (JEDEC), much software, and some operating systems like Windows still use this convention, storage vendors often prefer decimal units, which only adds to the confusion.

To solve this problem, the International Electrotechnical Commission (IEC) introduced binary prefixes specifically for binary units:

Binary units (IEC)	Decimal units (SI)	Unit Value
KiB (kibibyte)	kB (kilobyte)	1024^1
MiB (mebibyte)	MB (megabyte)	1024^2
GiB (gibibyte)	GB (gigabyte)	1024^3
TiB (tebibyte)	TB (terabyte)	1024^4
PiB (pebibyte)	PB (petabyte)	1024^5
EiB (exbibyte)	EB (exabyte)	1024^6
ZiB (zebibyte)	ZB (zettabyte)	1024^7
YiB (yobibyte)	YB (yottabyte)	1024^8
RiB (robibyte)	RB (ronnabyte)	1024^9
QiB (quebibyte)	QB (quettabyte)	1024^10

The Guidance

The clear guidance from standards organizations is: SI prefixes (kilo, mega, giga, etc.) should represent powers of 10 only, and if you mean powers of 2, you should use IEC binary prefixes (Ki, Mi, Gi, etc.).

Conclusion

Despite the inertia in the tech industry to equate 1 kilobyte with 1024 bytes, this convention can cause confusion, especially for non-technical users who notice discrepancies between advertised and actual storage capacity. While the binary convention is often acceptable depending on the context (particularly for RAM), using the correct prefixes—kilobyte for 1000 bytes and kibibyte for 1024 bytes—provides clarity and aligns with international standards.

The next time you're discussing storage or memory, consider using the proper terminology. Your users (and your sanity) will thank you.