Byte Converter

Convert between bytes, KB, MB, GB, TB (decimal) and KiB, MiB, GiB, TiB (binary).

Value

Source Unit

Side-by-Side Comparison Grid

Compare base-10 (decimal) and base-2 (binary) measurements at each tier.

Tier	Base-10 (Decimal - SI)	Base-2 (Binary - IEC)
Base / Bytes	Bytes (B) 1000000	Bytes (B) 1000000
Kilo / Kibi +2.4% diff	Kilobytes (KB) 1000	Kibibytes (KiB) 976.5625
Mega / Mebi +4.9% diff	Megabytes (MB) 1	Mebibytes (MiB) 0.95367432
Giga / Gibi +7.4% diff	Gigabytes (GB) 0.001	Gibibytes (GiB) 0.00093132257
Tera / Tebi +10.0% diff	Terabytes (TB) 1.0000e-6	Tebibytes (TiB) 9.0949e-7

Decimal vs binary storage units

Storage is measured in two systems. Decimal (SI): 1 KB = 1,000 bytes, 1 MB = 1,000,000 bytes — used by hard drive manufacturers and internet speeds. Binary (IEC): 1 KiB = 1,024 bytes, 1 MiB = 1,048,576 bytes — used by operating systems and RAM. This is why a 1 TB hard drive shows as ~931 GiB in Windows. Related: data storage converter.

Built and maintained by Meet Shah · Last updated 1 August 2026

What this tool is used for

Converting a size between decimal and binary units.
Checking a file size against a limit quoted in different units.
Comparing a drive's advertised capacity with reported free space.
Converting a quota figure for a config value.
Sizing a payload against a transfer budget.

Frequently Asked Questions

Why does my 1 TB drive show as 931 GB?: Because the manufacturer counted decimal and the operating system counts binary. 1 TB is 10¹² bytes, and Windows divides by 1024 three times to display it, giving 931 GiB — while labelling it GB. Nothing is missing; two conventions are being mixed in one sentence.
What is the difference between KB and KiB?: 1 KB is 1000 bytes; 1 KiB is 1024. The IEC introduced the kibi/mebi/gibi prefixes in 1998 specifically to end the ambiguity, and the gap widens with each step — 2.4% at kilo, 4.9% at mega, 7.4% at giga, and about 10% by tera.
Which system does each thing use?: Decimal: drive capacities, network speeds, and most Linux tooling with `--si`. Binary: RAM sizes always, Windows file sizes, and `ls -lh` by default. macOS switched to decimal in 10.6, which is why the same disk reports differently on two machines.
Why is RAM always binary?: Because address lines are physical. A memory chip is addressed by a whole number of bits, so its capacity is inevitably a power of two — there is no way to build a 1000-byte module. Storage has no such constraint, which is why only RAM is unambiguous.
Is a byte always eight bits?: In practice yes, but the guarantee is younger than it feels — historical machines used 6, 7 and 9-bit bytes, which is why network standards say octet when they mean exactly eight. Modern code can rely on 8; the terminology in older RFCs is a fossil of when it could not.

Common errors and gotchas

Mixing KB with KiB, which differ by 2.4% and compound at each step up the scale.
Confusing bits with bytes, a factor of eight throughout networking figures.
Assuming an operating system uses the same convention as the drive's label, which it often does not.
Reading a KiB figure as KB when comparing against a quota, which drifts further at each scale step.
Assuming the source and the destination use the same convention, which is rarely documented.