What is the difference between KB and KiB?

A kilobyte (KB) is 1000 bytes in the SI decimal system, while a kibibyte (KiB) is 1024 bytes in the IEC binary system. The names look similar but the binary unit is about 2.4 percent larger, and the gap widens for each higher prefix.

Why does my 1 TB drive show as about 931 GB?

Drive makers advertise 1 TB as one trillion bytes using SI units. Many operating systems then display the size using binary math but keep the decimal GB label, so one trillion bytes reads as roughly 931 of those binary gigabytes, which are really gibibytes.

How many bits are in a byte?

Eight. All conversions here treat one byte as exactly 8 bits, which is the universal modern definition. Network speeds are usually quoted in bits per second, while file sizes are quoted in bytes, a frequent source of an eightfold confusion.

When should I use IEC binary units?

Use binary units (KiB, MiB, GiB) when precision matters and the context is memory or block sizes, which are inherently powers of two. Use SI decimal units (KB, MB, GB) for storage marketing, bandwidth, and anywhere round decimal numbers are expected.

Does the converter handle very large or very small values?

Yes. Extremely large or tiny results are shown in scientific notation to stay readable, while ordinary sizes are shown as plain trimmed decimals. All arithmetic is done in bits internally to keep the conversions consistent.

Byte and Bit Size Converter

This converter shows a single data size in every common unit at once, covering both unit families that people routinely mix up: the SI decimal units that step by 1000 and the IEC binary units that step by 1024.

How it works

Every value is first reduced to a common base of bits, then divided back out into each target unit:

1 byte = 8 bits
SI:  1 KB  = 1000 B,  1 MB = 1000 KB,  1 GB = 1000 MB
IEC: 1 KiB = 1024 B,  1 MiB = 1024 KiB, 1 GiB = 1024 MiB

total_bits   = amount × bits_per_source_unit
target_value = total_bits / bits_per_target_unit

Because both families are anchored to the same bit count, you can read straight across from, say, gibibytes to gigabytes without any extra steps.

Example and tips

1 GiB equals 1.073741824 GB, 1024 MiB, and 8,589,934,592 bits. When you see a storage size that does not match expectations, the culprit is almost always a decimal-versus-binary mismatch: a 500 GB SSD holds 500 billion bytes, which a binary-counting tool reports as about 465 GiB. Quote bandwidth in bits and file sizes in bytes, and remember the factor of eight between them.