MB to GB Converter
Toggle between decimal (1000) and binary (1024) calculation to match your drive, cloud provider, or operating system display.
Enter amount in MB or MiB (we'll convert).
Pick decimal for disk labels, binary for OS values.
Key results
Decimal interpretation
1 GB = 1000 MB
Binary interpretation
1 GiB = 1024 MiB
Formulas
Decimal: GB = MB ÷ 1000
Binary: GiB = MiB ÷ 1024
1 MB (decimal) = 1,000,000 bytes
1 MiB (binary) = 1,048,576 bytes
If you’re comparing to a hard drive label or cloud storage plan, use decimal. If you’re matching what Windows, macOS, or Linux shows in “properties”, use binary.
MB to GB quick table (decimal)
| MB | GB (1000) | GiB (1024) |
|---|
Values rounded to 6 decimals.
Why two different ways?
Historically, computer memory grew in powers of 2, so using 1024 made sense (2¹⁰ = 1024). Storage manufacturers, however, followed SI prefixes: kilo = 1000, mega = 1,000,000, giga = 1,000,000,000. That’s why a “500 GB” drive shows about “465 GiB” on your computer.
Which one should I use?
- Use decimal (1000) when talking about network, cloud, drive labels, subscriptions.
- Use binary (1024) when matching OS-reported file sizes, RAM, or technical documentation that explicitly uses MiB/GiB.
FAQ
1. Is MB the same as MiB?
No. MB = 1,000,000 bytes, MiB = 1,048,576 bytes. They are close, but not identical.
2. Why is my 256 GB drive showing less?
Because 256 GB (decimal) = 256,000 MB, but your OS divides by 1024³ to get GiB, which gives a slightly smaller number.
Formula (LaTeX) + variables + units
','\
Decimal: GB = MB ÷ 1000 Binary: GiB = MiB ÷ 1024 1 MB (decimal) = 1,000,000 bytes 1 MiB (binary) = 1,048,576 bytes
- No variables provided in audit spec.
- NIST — Weights and measures — nist.gov · Accessed 2026-01-19
https://www.nist.gov/pml/weights-and-measures - NIST — SI units — nist.gov · Accessed 2026-01-19
https://www.nist.gov/pml/owm/metric-si/si-units
Last code update: 2026-01-19
- Initial audit spec draft generated from HTML extraction (review required).
- Verify formulas match the calculator engine and convert any text-only formulas to LaTeX.
- Confirm sources are authoritative and relevant to the calculator methodology.