About the MB to GB Converter
This MB to GB converter turns megabytes into gigabytes and lets you choose between the two conventions in use: decimal units, where 1 GB = 1,000 MB (used by storage makers, mobile carriers and macOS), and binary units, where 1 GiB = 1,024 MiB (used by Windows, RAM sizes and many developer tools).
Use it to check whether files fit on a USB drive or cloud plan, estimate how many photos or videos a phone can hold, compare mobile data allowances, or understand why a "500 GB" drive shows about 465 GB in Windows.
Alongside gigabytes you get the same amount in terabytes, kilobytes and bytes, and the result the other convention would give, so you can compare the two directly.
With the default inputs, the gigabytes is 1.5 GB. Change any value above to recalculate instantly.
How to use the mb to gb converter
- 1Enter the size in megabytes.
- 2Choose decimal for storage labels and data plans, or binary for RAM and Windows.
- 3Read the gigabytes at the top.
- 4Compare with the other-convention figure if numbers do not match your device.
Formula and method
In the SI (decimal) system, prefixes step by 1,000: 1 GB = 1,000 MB = 1,000,000 KB = 10^9 bytes. In the IEC (binary) system, prefixes step by 1,024: 1 GiB = 1,024 MiB = 2^30 bytes. Both are "correct"; they just count different sizes.
Kilobytes are MB × base, bytes are MB × base², and terabytes are GB ÷ base. The "other convention" output reinterprets your number with the opposite base, which explains most differences between advertised and displayed capacity.
- MB / MiB
- Megabytes (10^6 bytes) / mebibytes (2^20 bytes)
- GB / GiB
- Gigabytes (10^9 bytes) / gibibytes (2^30 bytes)
Worked examples
1,500 MB file (decimal)
Using decimal units, 1,500 ÷ 1,000 = 1.5 GB. Read in binary, the same number of MB would be 1,500 ÷ 1,024 = 1.465 GiB.
1,500 MiB in binary units
1,500 ÷ 1,024 = 1.465 GiB. Each MiB is 1,048,576 bytes, so the total is 1,572,864,000 bytes.
250,000 MiB virtual disk image
250,000 ÷ 1,024 = 244.14 GiB, and ÷ 1,024 again = 0.238 TiB.
Frequently asked questions
Is 1 GB 1000 MB or 1024 MB?+
Both are used. Under SI rules 1 GB = 1,000 MB, which is what drive makers and data plans use. Operating systems like Windows count 1,024 MB per GB (strictly a GiB, gibibyte).
Why does my 1 TB drive show about 931 GB?+
The maker counts 1 TB as 10^12 bytes. Windows divides by 1,024³ and shows 10^12 ÷ 1,073,741,824 ≈ 931 "GB" (really GiB). No space is missing.
How many MB is 1 GB of mobile data?+
Mobile carriers almost always use decimal units, so 1 GB of data is 1,000 MB. Some apps display 1,024 MB per GB, so totals may differ slightly.
What is the difference between MB and Mb?+
MB (capital B) is megabytes; Mb (lower-case b) is megabits. One byte is 8 bits, so a 100 Mb/s connection downloads about 12.5 MB per second.