Terms, acronyms, storage & speed ratings— oh my!

Paul Seiler -

In the beginning was the data and the data was made of bits and therefore the data was bits.

Perspective is fun, I promise. When reading both data storage and speed notations it is extremely important to remember your upper and lowercase b's.

  • b = bit
  • B = byte

8b = 1B
1B = 8b

After these first eight bits, notations will typically deal in multiples of one thousand ... sort of. Scientific notion's "Kilo" means one thousand and "Mega" means one million and, in a confusing number of cases, that is actually what they mean on the boxes advertising data storage and even speed/throughput ratings. However! Computer science deals in bits which effectively equates to base eight instead of a base ten system. It's also binary which means every bit is either a one or zero, but that's a topic for another day.

Common Bit Ratios— A Quick Reference Guide

8b = 8 bits = 1 Byte
8b times 2 = 16 bits = 2 Bytes
8b times 4 = 32 bits = 4 Bytes
8b times 8 = 64 bits = 8 Bytes
8b times 16 = 128 bits = 16 Bytes
8b times 32 = 256 bits = 256 Bytes
8b times 64 = 512 bits = 64 Bytes
8b times 128 = 1024 bits = 1Kb = 128 Bytes

Notation + Pre-calculated References

  • K = Kilo

1Kb = 1,024b = 128B
1KB = 8Kb = 1,024B = 8,192b

  • M = Mega

1Mb = 128KB = 1,024Kb = 131,072B = 1,048,576b
1MB = 8Mb = 1,024KB = 8,192Kb = 1,048,576B = 8,388,608b

  • G = Giga

1Gb = 128MB = 1,024Mb = 131,072KB = 1,048,576Kb = 134,217,728B = 1,073,741,824b
1GB = 8Gb = 1,024MB = 8,192Mb = 1,048,576KB = 8,388,608Kb = 1,073,741,824B = 8,589,934,592b

  • T = Tera

1Tb = 128GB = 1,024Gb = 131,072MB = 1,048,576Mb = 134,217,728KB = 1,073,741,824Kb = 137,438,953,472B = 1,099,511,627,776b
1TB = 8Tb = 1,024GB = 8,192Gb = 1,048,576MB = 8,388,608Mb = 1,073,741,824KB = 8,589,934,592Kb = 1,099,511,627,776B = 8,796,093,022,208b

  • P = Peta

1Pb = 128TB = 1,024Tb = 131,072GB = 1,048,576Gb ... and so on through 1,125,899,906,842,624b
1PB = 8Pb = 1,024TB = 8,192Tb = 1,048,576GB = 8,388,608Gb ... and so on through 9,007,199,254,740,992b

One terabyte is equal to 8e+12 bits. That's eight trillions bits. 8,000,000,000,000! Or at least it is when you're buying a hard drive. When you're storing data, one terabyte is actually 8,796,093,022,208 bits! So if you've got a whole terabyte of data to store, you need at least 1,024GB of real raw capacity. A 1TB drive from won't work, it's literally not big enough to store an actual 1TB set of data— you'll need a bigger drive. OH! Don't forget to leave yourself at least 20% of headroom for operational performance and the like. A completely full hard drive will come to a screaching hault, not to mention all the risks of data corruption and even complete drive failure. One terabyte of storage has now turned into a purchase of at least 1.2TB / 1,228.8GB / 10,555,311,626,650b which would require a sticker-purchase / commercially advertised 1.32942TB which is absolutely infurriating if you ask me, but this is this world we live in.