Data Storage Converter (Bytes, KB, MB, GB, TB)

Data storage is measured in bytes, and every larger unit is a multiple of the byte. Two systems are in use. Storage makers and the SI use decimal prefixes, so 1 kB = 1,000 bytes, 1 MB = 10⁶ bytes and 1 GB = 10⁹ bytes. Operating systems and memory chips often count in powers of two: 1 KiB = 1,024 bytes, 1 MiB = 2²⁰ bytes and 1 GiB = 2³⁰ bytes.

The gap grows with each step: 2.4% at the kilo level, 7.4% at giga and 10% at tera, which is why a “1 TB” drive appears as about 931 GB in Windows. This converter shows decimal and binary units side by side, so you can compare a drive label, a file size or a download quota in whichever system you need.

How to use the Data Storage Converter

1. Pick the unit you are starting from in the From menu and type your value.
2. Pick the unit you want in the To menu. The heading changes to match, for example “Gigabytes to Bytes Converter”.
3. The most common data size units are shown below at the same time, so you can compare them at a glance.
4. Type into any result to convert backwards, then use Copy results. The copied text starts with the heading for your chosen units.

Results update as you type. Everything is calculated in your browser.

How it works

Each of the 14 data size units on this page is defined by an exact factor relative to the byte, the base unit: 1 GB = 1 × 10⁹ B and 1 kB = 1,000 B, for example. The calculator first turns the value you type into bytes, then turns that into the unit you picked in the “To” menu and into kilobytes, megabytes and terabytes. Typing into any result works backwards the same way, so the gigabytes and bytes values always describe the same amount.

How to convert data size units

1. Choose the unit you have in the From menu and type the value, for example 1 GB.
2. Choose the unit you want in the To menu, for example bytes. The page heading changes to “Gigabytes to Bytes Converter”.
3. The calculator multiplies by the byte factor of the “from” unit and divides by the factor of the “to” unit: 1 GB × 1 × 10⁹ ÷ 1 = 1 × 10⁹ B.

1 gigabyte in common units

Gigabytes conversion table

Data size units explained

Gigabyte (GB)

A gigabyte is 1,000,000,000 bytes (SI). Phone storage and data plans are measured in GB.

Byte (B)

A byte is 8 bits, enough to store one character of plain English text.

Kilobyte (kB)

A kilobyte is 1,000 bytes in SI units. Some software uses “KB” for 1,024 bytes, properly called a kibibyte (KiB).

Megabyte (MB)

A megabyte is 1,000,000 bytes (SI). A typical smartphone photo is 2–5 MB.

Terabyte (TB)

A terabyte is 10¹² bytes (1,000 GB). Hard drives and SSDs are sold in TB; an operating system that counts in binary shows 1 TB as about 931 GiB.

Petabyte (PB)

A petabyte is 10¹⁵ bytes (1,000 TB), the scale of data-centre storage and large research datasets.

Kibibyte (KiB)

A kibibyte is 1,024 bytes (2¹⁰), the binary unit many programs label “KB”. It is 2.4% larger than a kilobyte.

Mebibyte (MiB)

A mebibyte is 1,048,576 bytes (2²⁰). Memory sizes and some file managers use it, often labelled “MB”.

Gibibyte (GiB)

A gibibyte is 1,073,741,824 bytes (2³⁰). Windows reports drive sizes in GiB but labels them “GB”, which is why drives look smaller than advertised.

Tebibyte (TiB)

A tebibyte is 2⁴⁰ bytes (1,024 GiB), about 10% more than a terabyte.

Bit (bit)

A bit is the smallest unit of digital information, a single 0 or 1. Eight bits make one byte, and network speeds are counted in bits.

Common mistakes to avoid

Mixing decimal units (1 GB = 10⁹ bytes) with binary units (1 GiB = 2³⁰ bytes), and bits with bytes.

Decimal (SI) vs binary units