GB/MB/TB converter
Convert data amounts between MB, GB and TB using decimal (1000-based) units; this converts storage/data quantity, not transfer speed.
Result
In megabytes (MB)
In gigabytes (GB)
In terabytes (TB)
As your computer may show it (GiB, 1024-based)
How to use this tool
- Enter an amount and switch the unit dropdown to match what you're converting from.
- Read the equivalent in the other two units.
Assumptions
- Uses decimal (1000-based) prefixes, as used by storage manufacturers and mobile data plans — operating systems sometimes instead use binary (1024-based) prefixes internally, which gives a slightly different-looking free-space figure.
Sources & reference data
Technical details: what the fields mean
- Amount
amount - Data amount — use the unit dropdown to enter it in MB, GB or TB.
Methodology
Uses decimal (1000-based) prefixes: 1000 MB = 1 GB and 1000 GB = 1 TB. These are data amounts, not rates such as Mbps or MB/s.
Worked example
2.5GB
Inputs: Amount: 2.5 (unit: gb)
Result: 2500.00 MB, 2.5000 GB, 0.002500 TB — about 2.33 GiB in a 1024-based file manager.
Why does my new 1 TB drive show about 931 GB?
Inputs: Amount: 1 (unit: tb)
Result: 1,000,000 MB = 931.32 GiB. Nothing is missing: the drive is sold in decimal units, and Windows labels 1024-based GiB as 'GB'.
A 256 GB phone
Inputs: Amount: 256 (unit: gb)
Result: 238.42 GiB before the operating system and apps take their share.
Practical guidance
- If a file manager or operating system shows a slightly different number than expected, it may be using 1024-based (binary) units internally rather than the 1000-based (decimal) units used here and by most storage/data-plan marketing.
Common mistakes
- Assuming 1GB always equals exactly 1024MB — that's the binary convention some operating systems use internally; storage and data plans are usually sold using the 1000-based decimal convention used here.
FAQs
How many MB is 1GB?
1000MB, using the standard decimal convention used for storage and data plans (some operating systems instead show 1024MB internally).
Why does a 1TB hard drive show 931GB?
The drive holds 1,000,000,000,000 bytes. Windows divides by 1024 three times and calls the result 'GB', giving 931. The binary unit's proper name is the gibibyte (GiB).
What's the difference between GB and GiB?
A gigabyte (GB) is 1,000,000,000 bytes; a gibibyte (GiB) is 1,073,741,824 bytes (1024³). The IEC binary prefixes (KiB, MiB, GiB, TiB) were introduced to remove this ambiguity.
Last reviewed: 2026-10-11
Uses the 1000-based decimal convention — some operating systems report file/storage sizes using 1024-based binary units instead, which will look slightly different.
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