GB to MB Converter
Convert gigabytes to megabytes instantly. One gigabyte equals exactly 1,000 megabytes. Type in either box to convert both ways, then use the chart, worked examples and everyday sizes below.
How to convert gigabytes to megabytes
Worked example: convert 128 gigabytes to megabytes. Using megabytes ← gigabytes × 1,000, we get 128 × 1,000 = 128,000 MB. To check the result, convert back: 128,000 MB ÷ 1,000 = 128 GB.
Gigabytes to megabytes chart
| Gigabytes (GB) | Megabytes (MB) |
|---|---|
| 1 GB | 1,000 MB |
| 2 GB | 2,000 MB |
| 3 GB | 3,000 MB |
| 4 GB | 4,000 MB |
| 5 GB | 5,000 MB |
| 6 GB | 6,000 MB |
| 8 GB | 8,000 MB |
| 10 GB | 10,000 MB |
| 12 GB | 12,000 MB |
| 15 GB | 15,000 MB |
| 20 GB | 20,000 MB |
| 25 GB | 25,000 MB |
| 30 GB | 30,000 MB |
| 40 GB | 40,000 MB |
| 50 GB | 50,000 MB |
| 75 GB | 75,000 MB |
| 100 GB | 100,000 MB |
| 150 GB | 150,000 MB |
| 200 GB | 200,000 MB |
| 250 GB | 250,000 MB |
| 500 GB | 500,000 MB |
| 1,000 GB | 1,000,000 MB |
Megabytes to gigabytes (reverse)
| Megabytes (MB) | Gigabytes (GB) |
|---|---|
| 1 MB | 0.001 GB |
| 2 MB | 0.002 GB |
| 5 MB | 0.005 GB |
| 10 MB | 0.01 GB |
| 20 MB | 0.02 GB |
| 50 MB | 0.05 GB |
| 100 MB | 0.1 GB |
| 250 MB | 0.25 GB |
| 500 MB | 0.5 GB |
| 1,000 MB | 1 GB |
About the gigabyte and the megabyte
A gigabyte is 1,000 megabytes in decimal; one GiB (gibibyte) is 1,073,741,824 bytes. Phone storage, RAM and mobile data plans are sold in GB.
A megabyte is 1,000,000 bytes in decimal. A typical smartphone photo is a few megabytes and an MP3 song around 3 to 5 MB. In binary terms 1 MiB is 1,048,576 bytes.
One gigabyte is 1,000 times the size of one megabyte, so it takes fewer gigabytes than megabytes to express the same amount.
Everyday sizes in gigabytes and megabytes
| Everyday example (approximate) | In gigabytes | In megabytes |
|---|---|---|
| A web page | 0.002 GB | 2 MB |
| A phone photo | 0.003 GB | 3 MB |
| A 3-minute MP3 song | 0.005 GB | 5 MB |
| A 2-hour HD movie | 3 GB | 3,000 MB |
| A Blu-ray disc | 25 GB | 25,000 MB |
| A big video game | 100 GB | 100,000 MB |
Gigabytes to megabytes FAQ
How many megabytes are in one gigabyte?
One gigabyte equals exactly 1,000 megabytes. In the other direction, one megabyte equals 0.001 gigabytes.
How do I convert gigabytes to megabytes without a calculator?
convert 128 gigabytes to megabytes. Using megabytes ← gigabytes × 1,000, we get 128 × 1,000 = 128,000 MB. To check the result, convert back: 128,000 MB ÷ 1,000 = 128 GB. For a quick estimate, round the factor to 1,000. Then 128 GB is about 128,000 MB, compared with the exact 128,000 MB (an error of 0%). That is close enough for planning, but use the calculator above when the number matters.
What is a Blu-ray disc in megabytes?
A Blu-ray disc is about 25 gigabytes, which is 25,000 megabytes. Treat that as an approximate everyday figure rather than an official measurement.
Are the gigabytes and megabytes the same in every country?
Decimal GB = 10^9 bytes; binary GiB = 1,073,741,824 bytes, which is why a "500 GB" drive shows about 465 GB in Windows. Decimal MB = 1,000,000 bytes; binary MiB = 1,048,576 bytes.