Data Size Converter

Bytes, KB, MB, GB, TB and KiB, MiB, GiB. Runs in your browser; nothing is uploaded.

1 B = 0.000001 MB
Bit (b)8
Byte (B)1
Kilobit (kb)0.008
Megabit (Mb)0.000008
Gigabit (Gb)8e-9
Kilobyte (KB)0.001
Megabyte (MB)0.000001
Gigabyte (GB)1e-9
Terabyte (TB)1e-12
Petabyte (PB)1e-15
Kibibyte (KiB)0.0009765625
Mebibyte (MiB)9.536743e-7
Gibibyte (GiB)9.313226e-10
Tebibyte (TiB)9.094947e-13
Pebibyte (PiB)8.881784e-16

KB, MB, GB use powers of 1000 (SI). KiB, MiB, GiB use powers of 1024, which is what Windows shows as "KB/MB/GB".

How to use the data size converter

Enter a number in Value and pick the source and target units. The headline conversion updates as you type, and the table below displays the exact value across all 15 bit, decimal (SI), and binary (IEC) storage units simultaneously.

Decimal (SI) vs. Binary (IEC) units explained

Data sizes are expressed using two different standards, which is a frequent source of confusion between disk manufacturers and operating systems:

  • Decimal (SI) units — KB, MB, GB, TB, PB: based on powers of 1,000 (103). Used by SSD, hard drive, and flash drive manufacturers, macOS (since Snow Leopard), iOS, Linux distributions, and network transfer rates.
  • Binary (IEC) units — KiB, MiB, GiB, TiB, PiB: based on powers of 1,024 (210). Used for RAM modules, operating system memory allocation, and file sizes reported in Microsoft Windows (which displays binary values using the labels "KB", "MB", and "GB").
  • Bits vs. Bytes: 1 Byte (B) equals 8 bits (b). Internet and network speeds are normally quoted in bits per second (kb/s, Mb/s, Gb/s), whereas file and memory sizes are measured in bytes.

Data size conversion reference table

Decimal (SI) UnitDecimal BytesBinary (IEC) UnitBinary Bytes
1 Kilobyte (KB)1,000 B (103)1 Kibibyte (KiB)1,024 B (210)
1 Megabyte (MB)1,000,000 B (106)1 Mebibyte (MiB)1,048,576 B (220)
1 Gigabyte (GB)1,000,000,000 B (109)1 Gibibyte (GiB)1,073,741,824 B (230)
1 Terabyte (TB)1012 B1 Tebibyte (TiB)1,099,511,627,776 B (240)
1 Petabyte (PB)1015 B1 Pebibyte (PiB)1,125,899,906,842,624 B (250)

Frequently asked questions

Why does a 1 TB hard drive or SSD show as 931 GB in Windows?
Storage manufacturers label drive capacity using decimal SI units, where 1 TB = 1,000,000,000,000 bytes (1012). Windows divides that byte count by powers of 1,024 (230 = 1,073,741,824 bytes per GiB) and labels the result "GB". 1,000,000,000,000 ÷ 1,073,741,824 ≈ 931.32 GiB.
What is the difference between MB and MiB (or GB and GiB)?
MB (megabyte) and GB (gigabyte) are decimal SI units based on powers of 1,000: 1 MB = 1,000,000 bytes and 1 GB = 1,000,000,000 bytes. MiB (mebibyte) and GiB (gibibyte) are binary IEC units based on powers of 1,024: 1 MiB = 1,048,576 bytes and 1 GiB = 1,073,741,824 bytes.
How do I convert internet speed in Mbps to download speed in MB/s?
Network speeds are measured in megabits per second (Mbps), while file sizes are measured in megabytes (MB). Because 1 byte equals 8 bits, divide the speed in Mbps by 8: for example, a 100 Mbps connection transfers up to 12.5 MB per second.

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