Data Storage Converter — bytes, KB, MB, GB, TB & PB
Convert data storage units online free — bytes, kilobytes, megabytes, gigabytes, terabytes and petabytes. Supports both binary (1024-based) and decimal (1000-based) standards. Instant, no sign-up.
Last updated: June 2026
Decimal units (powers of 1,000)
Binary units (powers of 1,024)
About this tool
Bytes, gigabytes and the GB-versus-GiB confusion
Few measurements cause as much confusion as digital storage, because the same prefixes — kilo, mega, giga — mean two different things. This data storage converter shows both systems at once: the decimal units (KB, MB, GB, TB, PB) that storage makers advertise, based on powers of 1,000, and the binary units (KiB, MiB, GiB, TiB, PiB) that operating systems use, based on powers of 1,024.
That single difference explains a question almost everyone has asked: why does a "1 TB" drive show as about 931 GB in Windows? The manufacturer counted in decimal (1 TB = 1,000,000,000,000 bytes) while the OS displays the same bytes in binary units. No space is missing — it's purely a difference of counting. Enter any value here and you'll see exactly how the decimal and binary figures line up.
The converter also makes the bit-versus-byte distinction clear: there are 8 bits in a byte, which is why network speeds quoted in megabits per second translate to roughly an eighth as many megabytes per second when downloading. Whether you're sizing a backup, planning cloud storage, or just satisfying your curiosity, every figure is computed locally in your browser — instant, free and private.
How it works
Three quick steps — no account, nothing uploaded to a server.
Type a size
Enter a value in any decimal or binary unit.
See both systems
Decimal (GB) and binary (GiB) update at once.
Understand the gap
See why advertised and reported sizes differ.
FAQ
Frequently asked questions
What is the difference between GB and GiB?
A gigabyte (GB) is a decimal unit equal to 1,000 megabytes (10⁹ bytes), while a gibibyte (GiB) is a binary unit equal to 1,024 mebibytes (2³⁰ bytes). One GiB is about 7.4% larger than one GB. Storage makers advertise in GB, but operating systems often report in GiB, which is why a '1 TB' drive shows as roughly 931 GiB.
How many MB are in a GB?
In decimal terms there are 1,000 megabytes in a gigabyte. In binary terms there are 1,024 mebibytes (MiB) in a gibibyte (GiB). This converter shows both systems at once so you can see exactly which figure applies.
How many bytes are in a kilobyte?
A decimal kilobyte (KB) is 1,000 bytes, while a binary kibibyte (KiB) is 1,024 bytes. The terms are often used loosely, but the converter distinguishes them precisely. There are 8 bits in a byte.
Why does my new hard drive show less space than advertised?
Drive manufacturers measure capacity in decimal units (1 GB = 1,000,000,000 bytes), but Windows reports usable space in binary units (1 GiB = 1,073,741,824 bytes) while still labelling it 'GB'. The data isn't missing — it's the same number of bytes counted in different units. Enter your drive size to see the binary equivalent.
What is the difference between bits and bytes?
A byte is 8 bits. Storage is usually measured in bytes (and their multiples KB, MB, GB), while network and data-transfer speeds are usually measured in bits per second. That's why a '100 Mbps' connection downloads at around 12.5 megabytes per second — divide by 8.
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