MB to GB Converter — Megabytes to Gigabytes (Decimal & Binary)
Enter any number of megabytes to instantly see the equivalent in gigabytes (decimal GB = ÷1 000), gibibytes (binary GiB = ÷1 024), terabytes, kilobytes, bytes and bits — with a clear bar showing why decimal GB and binary GiB differ.
Decimal (SI): 1 GB = 1 000 MB = 1 000 000 000 bytes
- 1
Bytes
1,024 MB × 1,000,000 = 1,024,000,0001 MB = 10⁶ bytes in the SI decimal standard - 2
Gibibytes (binary)
1,024,000,000 ÷ 1,073,741,824 = 0.9536741 GiB = 2³⁰ bytes — the binary standard used by most OS file managers - 3
Gigabytes (decimal)
1,024 ÷ 1,000 = 1.024000
How does this calculator work?
Divide MB by 1 000 to get GB (decimal, used by storage manufacturers). Divide MB by 1 048.576 to get GiB (binary IEC, used by most OS file managers). A 1 024 MB file = 1.024 GB (decimal) = 1.000 GiB (binary). The ~7.4% gap per gigabyte between the two is why your "1 TB" drive appears as ~931 GB in Windows.
Formula
How this is calculated
Two competing naming conventions define what a "gigabyte" means, and the mismatch is the source of nearly every "my hard drive shows less space than advertised" complaint. The decimal (SI) convention used by storage manufacturers defines 1 GB = 1 000 MB = 10⁹ bytes, making the maths clean and the drive capacity numbers as large as possible. The binary (IEC) convention used by operating systems defines 1 GiB = 1 024 MiB = 2³⁰ = 1 073 741 824 bytes, because memory addressing is naturally powers of two.
The gap between the two grows with each prefix step: 1 KB vs 1 KiB differ by 2.4%; 1 MB vs 1 MiB by 4.9%; 1 GB vs 1 GiB by 7.4%; 1 TB vs 1 TiB by 9.9%. A "1 TB" drive (10¹² bytes) appears as only ~931 GiB in Windows because Windows reports binary GiB while labelling them "GB". macOS switched to reporting decimal GB in 2009, so the same drive shows "1 TB".
This calculator uses the unambiguous two-step conversion: MB × 1 000 000 = bytes (decimal definition), then bytes ÷ 1 073 741 824 = GiB. Both results are shown so you can match whichever your device displays.
Frequently asked questions
In the decimal (SI) system used by storage manufacturers: 1 GB = 1 000 MB exactly. In the binary (IEC) system: 1 GiB = 1 024 MiB = 1 048.576 MB. So if someone says "1 GB" they almost always mean 1 000 MB; if an OS shows GiB but calls it GB, each "GB" = 1 024 MiB.
The phone's NAND flash is rated at 256 × 10⁹ bytes by the manufacturer (decimal). The OS reports storage in GiB (binary) but labels it "GB". 256 × 10⁹ bytes ÷ 1 073 741 824 ≈ 238.4 GiB, which appears as "238 GB". No storage is missing — it is purely a unit labelling convention.
For precision use MiB (IEC) when you mean powers of 1 024 and MB when you mean powers of 1 000. In practice, consumer software and everyday speech use "MB" for both, so always check the context. Hard-drive specs and cloud storage: decimal. RAM, OS file sizes, RAM-like firmware: binary.
Also known as
TG we-Calculate Editorial Team. (2026). MB to GB Converter — Megabytes to Gigabytes (Decimal & Binary) [Online calculator]. TG we-Calculate. https://we-calculate.com/calculator/mb-to-gb-converter
TG we-Calculate Editorial Team. "MB to GB Converter — Megabytes to Gigabytes (Decimal & Binary)." TG we-Calculate. 2026. https://we-calculate.com/calculator/mb-to-gb-converter.
TG we-Calculate Editorial Team, "MB to GB Converter — Megabytes to Gigabytes (Decimal & Binary)," TG we-Calculate, 2026. [Online]. Available: https://we-calculate.com/calculator/mb-to-gb-converter
@misc{wecalculate_mb_to_gb_converter, title = {MB to GB Converter — Megabytes to Gigabytes (Decimal & Binary)}, author = {{TG we-Calculate Editorial Team}}, howpublished = {\url{https://we-calculate.com/calculator/mb-to-gb-converter}}, year = {2026}, note = {TG we-Calculate} }
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