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GB to MB

One gigabyte (10⁹) is 1,000 megabyte (10⁶). Enter any value and the answer updates as you type.

25 units in this converter

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Decimals, fractions such as 3/4, and scientific notation such as 1.2e3 all work.

Gigabyte (10⁹) to Megabyte (10⁶) at a glance

21 rows
Gigabyte (10⁹)Megabyte (10⁶)
1 GB1,000 MB
2 GB2,000 MB
3 GB3,000 MB
4 GB4,000 MB
5 GB5,000 MB
6 GB6,000 MB
7 GB7,000 MB
8 GB8,000 MB
9 GB9,000 MB
10 GB10,000 MB
15 GB15,000 MB
20 GB20,000 MB
25 GB25,000 MB
30 GB30,000 MB
40 GB40,000 MB
50 GB50,000 MB
75 GB75,000 MB
100 GB100,000 MB
250 GB250,000 MB
500 GB500,000 MB
1,000 GB1,000,000 MB

Quick pairs

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Why people convert gb to mb

File size estimates, storage planning, and comparing a file's size against available space all need this conversion, complicated by the fact that operating systems and manufacturers do not always agree on whether a gigabyte means 1,000 megabytes or 1,024, a small but real discrepancy that adds up once file sizes get into the hundreds of gigabytes, which is why a drive advertised at a round number often shows a smaller figure once it is plugged in and formatted.

Mobile data plans add a second everyday case: a carrier sells a monthly allowance in gigabytes, say 5 GB, while individual app updates, podcast episodes, and photo backups are listed in megabytes, so a user tracking how many 150 MB app updates fit into a 5,000 MB allowance is running this exact conversion, just in reverse.

How the gigabyte (10⁹) to megabyte (10⁶) conversion works

This GB-to-MB pair uses the decimal, SI-style definitions: 1 gigabyte (10⁹ bytes) equals exactly 1,000 megabytes (10⁶ bytes), a factor of 1,000 with no rounding involved.

MB = GB × 1,000

A single DVD's 4.7 GB capacity converts to 4.7 × 1,000 = 4,700 MB. A typical phone app update of 1.5 GB converts to 1.5 × 1,000 = 1,500 MB. A 64 GB storage tier converts to 64 × 1,000 = 64,000 MB.

Going the other way, divide by 1,000 (or multiply by 0.001): 250 MB of downloaded files is 250 × 0.001 = 0.25 GB of a monthly data allowance.

Because the factor is a clean power of ten, there's no precision to lose in this specific conversion; the only rounding that matters is how many decimal places a file size display chooses to show.

The mistake specific to this pair is assuming 1 GB equals 1,024 MB instead of 1,000. That 1,024-based value is actually the gibibyte-to-mebibyte relationship (GiB to MiB), a related but different pair of units; mixing the two is exactly why a drive labeled "1 TB" shows up as roughly 931 GiB in an operating system that silently uses the binary definition under the decimal label.

Questions

How many megabytes are in 2.5 gigabytes?

2.5 gigabytes equals 2.5 × 1,000 = 2,500 megabytes.

How do I convert megabytes back to gigabytes?

Divide by 1,000. 7,500 MB, for example, equals 7,500 / 1,000 = 7.5 GB.

Why do file sizes get listed in GB sometimes and MB other times?

Smaller files and individual downloads are easier to read in megabytes, while storage capacities, data plans, and large media libraries are easier to read in gigabytes; most interfaces simply pick whichever unit keeps the displayed number in a comfortable range.

Is there a fast way to convert GB to MB in my head?

Move the decimal point three places to the right. 3.2 GB becomes 3,200 MB instantly, since multiplying by 1,000 is just shifting the decimal.

What's the most common mistake when converting GB to MB?

Using 1,024 instead of 1,000 as the multiplier. That value belongs to the binary GiB-to-MiB conversion, not this decimal GB-to-MB one, and mixing them up is exactly why a drive's labeled capacity and its displayed capacity in an operating system don't quite match.

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