Data Storage Converter
Convert digital storage across every common unit — bit, byte, kilobyte, megabyte, gigabyte, terabyte and petabyte — under either the decimal standard (powers of 1000, used by drive manufacturers and networking) or the binary standard (powers of 1024, used by operating systems and memory). Switching standards instantly shows why a "1 TB" drive appears as about 931 GB in your file manager: identical bytes, measured against a different yardstick. Eight bits make a byte, and every conversion here is exact.
How to use this tool
- Enter the amount of storage.
- Choose the unit you have and the unit you want.
- Pick the decimal (1000) or binary (1024) standard — switch any time to compare.
- Read the result and the full table of equivalents.
- Use decimal for drive and network figures; use binary to match what your OS reports.
The formula
Digital storage is counted in bits and bytes (8 bits = 1 byte). Larger units scale by 1000 under the decimal (SI) standard or by 1024 under the binary (IEC) standard, which is the source of most "why is my drive smaller than advertised" confusion.
bits = value × unit_factor
decimal: 1 KB = 1000 B, 1 MB = 1000 KB, …
binary: 1 KiB = 1024 B, 1 MiB = 1024 KiB, …- bit
- Smallest unit; 8 bits = 1 byte
- decimal
- Powers of 1000 (drive marketing, networking)
- binary
- Powers of 1024 (operating systems, memory)
A "1 TB" drive holds 1,000,000,000,000 bytes (decimal), which an operating system counting in binary reports as about 931 GiB — the same bytes, a different yardstick.
Worked examples
Drive vs OS
- Given
- 1 TB (decimal)
- Result
- ≈ 931 GB (binary)
A 1 TB drive holds 10¹² bytes. Measured in binary gigabytes (1024³), that is about 931 — the "missing" space is just a different unit.
Bits to bytes
- Given
- 1 byte
- Result
- 8 bits
A byte is always 8 bits, in either standard.
File in MB
- Given
- 1 GB (decimal)
- Result
- 1000 MB
Under the decimal standard each step multiplies by 1000, so a gigabyte is exactly 1000 megabytes.
Frequently asked questions
Drive makers count in decimal units, where 1 TB is 1,000,000,000,000 bytes. Operating systems usually count in binary, where a "gigabyte" is 1,073,741,824 bytes. The same bytes divided by the larger binary unit give a smaller number, so a 1 TB drive shows as about 931 GB. No space is missing.
Decimal (SI) scales by powers of 1000 — kilo, mega, giga each add three zeros. Binary (IEC) scales by powers of 1024, reflecting how memory is addressed. Strictly, binary units are named KiB, MiB, GiB, but many systems still label them KB, MB, GB, which is the source of much confusion.
Eight. This is fixed in both standards. Bits (lowercase b) are typically used for data rates and bytes (uppercase B) for storage, so watch the capitalisation — an eightfold difference hides in it.
Use decimal for drive capacities, file transfer figures and network speeds, since that is how they are quoted. Use binary when matching what Windows or a file manager reports for file and disk sizes. This tool lets you switch instantly to see both.
Yes. Everything is computed from an exact number of bits using integer scale factors, so no rounding error creeps in. Only the final displayed figure is rounded, and very large or very small results are shown in scientific notation to stay readable.
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