GB to MB Converter
Convert gigabytes to megabytes — a thousand to the gigabyte in the decimal units storage is sold in. Results update as you type; exact factors shown.
One gigabyte (10⁹) is 1,000 megabyte (10⁶) — see the exact factor, not a rounded rule of thumb.
How the gb to mb converter works
Storage converts through the byte (8 bits). Drive makers and network speeds use decimal prefixes (1 GB = 10⁹ bytes); operating systems often report binary units (1 GiB = 2³⁰ = 1,073,741,824 bytes) — sometimes labelled "GB". The gap is 7.4% at the gigabyte and 10% at the terabyte.
The UK is metric for most trade and science but keeps miles, pints, stone and mpg (with the imperial gallon) in daily life.
Common data conversions
| From | To | Units |
|---|---|---|
| 0.5 GB | 500 MB | gigabyte (10⁹) to megabyte (10⁶) |
| 1 GB | 1,000 MB | gigabyte (10⁹) to megabyte (10⁶) |
| 2 GB | 2,000 MB | gigabyte (10⁹) to megabyte (10⁶) |
| 4 GB | 4,000 MB | gigabyte (10⁹) to megabyte (10⁶) |
| 8 GB | 8,000 MB | gigabyte (10⁹) to megabyte (10⁶) |
| 16 GB | 16,000 MB | gigabyte (10⁹) to megabyte (10⁶) |
| 32 GB | 32,000 MB | gigabyte (10⁹) to megabyte (10⁶) |
| 64 GB | 64,000 MB | gigabyte (10⁹) to megabyte (10⁶) |
| 128 GB | 128,000 MB | gigabyte (10⁹) to megabyte (10⁶) |
| 256 GB | 256,000 MB | gigabyte (10⁹) to megabyte (10⁶) |
| 512 GB | 512,000 MB | gigabyte (10⁹) to megabyte (10⁶) |
| 1,000 GB | 1,000,000 MB | gigabyte (10⁹) to megabyte (10⁶) |
Units in this converter and their exact factors
| Unit | Symbol | One unit in bytes |
|---|---|---|
| bit | bit | 0.125 byte |
| byte | B | 1 byte |
| kilobyte (10³) | kB | 1,000 byte |
| megabyte (10⁶) | MB | 1,000,000 byte |
| gigabyte (10⁹) | GB | 1,000,000,000 byte |
| terabyte (10¹²) | TB | 1,000,000,000,000 byte |
| kibibyte (2¹⁰) | KiB | 1,024 byte |
| mebibyte (2²⁰) | MiB | 1,048,576 byte |
| gibibyte (2³⁰) | GiB | 1,073,741,824 byte |
| tebibyte (2⁴⁰) | TiB | 1,099,511,627,776 byte |
FAQFrequently asked questions about data conversion
How many MB in a GB?
1,000 in decimal units; 1,024 MiB in the binary units an operating system shows.
Which does my phone use?
Storage is sold in decimal, but most systems display binary — which is why a "64 GB" phone shows about 59.6 GiB before the system takes its share.
How many MB is a photo?
Typically 2–5 MB for a phone JPEG, 20–50 MB for a raw file.
How much data does an hour of video use?
About 1 GB at 1080p, 3–7 GB at 4K.
Is a megabit the same?
No — eight megabits to the megabyte.
Where these figures come from
- BIPM — The International System of Units (SI Brochure, 9th edition) — definitions of the base and derived units.
- NIST Special Publication 811 — Guide for the Use of the International System of Units — the exact conversion factors used here.
- National Physical Laboratory (NPL) — United Kingdom's national measurement authority.
Last checked: September 2026. Conversion factors are fixed by definition and do not change with tax years or regulations.