Published January 8, 2026
Here’s a throwback from my undergrad1 degree: depending on the context, K, M, G, T can be base 10 OR base 2.
For a quick refresher: K, M, G, T are kilo-, mega-, giga-, and peta-.
Here’s the tl;dr: Ki == base 2 (210), K == base 10 (103).
Read on for more.
Frequencies & Rates
K, M, G, T == 103, 106, 109, 1012, respectively
- Anything with time in the denominator
- Hz has time in the denominator (cycles/sec)
Memory Sizes
K, M, G, T == 210, 220, 230, 240, respectively
- Any addressable quantity of memory
- Ideally, replaced by Ki, Mi, Gi, Ti
There’s far too many instances of K, M, G, T in the wild that would benefit from explicitly being written as Ki, Mi, Gi, Ti. Because of this, you have to infer the mean…
Published January 8, 2026
Here’s a throwback from my undergrad1 degree: depending on the context, K, M, G, T can be base 10 OR base 2.
For a quick refresher: K, M, G, T are kilo-, mega-, giga-, and peta-.
Here’s the tl;dr: Ki == base 2 (210), K == base 10 (103).
Read on for more.
Frequencies & Rates
K, M, G, T == 103, 106, 109, 1012, respectively
- Anything with time in the denominator
- Hz has time in the denominator (cycles/sec)
Memory Sizes
K, M, G, T == 210, 220, 230, 240, respectively
- Any addressable quantity of memory
- Ideally, replaced by Ki, Mi, Gi, Ti
There’s far too many instances of K, M, G, T in the wild that would benefit from explicitly being written as Ki, Mi, Gi, Ti. Because of this, you have to infer the meaning from the context of the usage. To reiterate:
- Anything with a per unit time == 10N
- Anything with bit/bytes and no time == 2N
Here’s a handy Wikipedia section on the two.
To add to the fun, the spelling2 changes too:
- Ki == kibibyte
- Mi == mebibyte
- Gi == gibibyte
- Ti == tebibyte
The reason this is important is base 2 for a given unit is larger than the base 10 and increases with each jump e.g. Ki vs K is ~2% while Ti vs T is ~9%.
In my experience it’s common to see these unit confusions come up e.g. when looking at network & data transfer speeds (base 10) and then comparing it to the physical size (on disk, base 2). You’ll have a bandwidth that looks better (because as established above, base 2 > base 10 for a given unit) and product marketing that, while technically correct, is misleading because 1TB < 1TiB.
That’s all, folks. May your units be correct and future readings less dry and pedantic than this. 🤓
When writing this I referenced a page from a handout that was created by a late professor, R. M. Kieckhafer.↩︎ 1.
Honestly, I prefer the cuteness of these.↩︎
I love hearing from readers so please feel free to reach out.
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Last modified January 7, 2026 #programming #math #meta