Data Storage Converter
Convert bytes, KB, MB, GB and TB.
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Convert any data size into bytes, kilobytes, megabytes, gigabytes, and terabytes — and see it in both the decimal scale (1 KB = 1,000 bytes, used by drive makers) and the binary scale (1 KiB = 1,024 bytes, used by many operating systems).
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How to Convert Data Storage — The Quick Answer
Digital storage uses powers of 1,000 (decimal, e.g. KB) or powers of 1,024 (binary, e.g. KiB). Multiply up, or divide down, by 1,000 or 1,024 per step. This is why a '1 TB' drive shows as about 931 GiB in your file manager.
Shortcut
decimal: 1 KB = 1,000 bytes, 1 MB = 1,000 KB … binary: 1 KiB = 1,024 B, 1 MiB = 1,024 KiB …
Fact-Checking Claims You May Have Seen Online
A 1 TB hard drive holds exactly 1,000 GB of your files
Not quite
Drive makers use decimal (1 TB = 1,000 GB = 1,000,000,000,000 bytes), but operating systems often report in binary units, where that same capacity is about 931 GiB. The drive isn't smaller — the units differ.
The two scales, side by side
| Decimal (SI) | Bytes | Binary (IEC) | Bytes |
|---|---|---|---|
| 1 KB | 1,000 | 1 KiB | 1,024 |
| 1 MB | 1,000,000 | 1 MiB | 1,048,576 |
| 1 GB | 1,000,000,000 | 1 GiB | 1,073,741,824 |
| 1 TB | 1e12 | 1 TiB | 1.0995e12 |
Most of the confusion around storage sizes comes from mixing the two scales. Manufacturers of drives and network speeds generally use decimal; RAM and many file systems use binary.
How It Works
The Method
Power-of-1000 vs power-of-1024
Formula
decimal: 1 KB = 1,000 B, 1 MB = 1,000 KB, 1 GB = 1,000 MB … binary: 1 KiB = 1,024 B, 1 MiB = 1,024 KiB, 1 GiB = 1,024 MiB …
Variables
Decimal (SI) units
KB, MB, GB, TB each step up by 1,000. This is the scale used by hard-drive and SSD manufacturers, and by network-speed figures — the storage you're sold is measured this way.
Binary (IEC) units
KiB, MiB, GiB, TiB each step up by 1,024 (2¹⁰). Because computers work in powers of two, many operating systems report file and disk sizes in these units — which is why the numbers look 'smaller' than the drive label.
Note: One TiB is about 1.0995 TB, so a 1 TB drive shows as roughly 931 GiB once a binary-reporting system interprets it. Both figures describe the same physical capacity.
Last updated: October 5, 2026
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Frequently Asked Questions
How many MB are in a GB?
In decimal units (used by drive makers), 1 GB = 1,000 MB. In binary units (used by many operating systems), 1 GiB = 1,024 MiB. This calculator shows both so you can match whichever scale your context uses.
Why does my 1 TB drive show as 931 GB?
Because it's 931 GiB, not 931 'decimal' GB. The drive holds 1,000,000,000,000 bytes — the maker's '1 TB'. Your operating system divides that by 1,024³ (binary) rather than 1,000³, giving about 931 GiB. The drive is the same size; only the unit differs.
What's the difference between KB and KiB?
KB (kilobyte) is 1,000 bytes under the decimal/SI standard, while KiB (kibibyte) is 1,024 bytes under the binary/IEC standard. Officially they're different units, which is exactly why storage sizes can seem inconsistent between marketing and your file manager.
How many bytes are in a megabyte?
1,000,000 bytes in the decimal definition (1 MB), or 1,048,576 bytes in the binary definition (1 MiB). The difference is about 4.9% — small for one step, but it compounds as you go up to GB and TB.