MB to GB Converter
Convert megabytes to gigabytes (MB to GB), decimal and binary
1 MB = 0.001 GB, so 1,000 MB = 1 GB. To convert MB to GB, divide the megabytes by 1,000. In binary units, 1,024 MiB = 1 GiB.
Megabytes to Gigabytes converter
Live1 GB = 1,000 MB, the SI definition used by drive makers and macOS.
- 0.95367432 MiB
- 976.5625 KiB
- 1,000 KB
- 0.0009313226 GiB
- 8,000 kbit
How to convert megabytes to gigabytes
The megabyte and the gigabyte both use SI prefixes, the same ones as in kilometer and gigawatt. Mega means one million and giga means one billion, so a megabyte is 1,000,000 bytes and a gigabyte is 1,000,000,000 bytes. One gigabyte therefore holds exactly 1,000 megabytes, and converting is a single division by 1,000: move the decimal point three places to the left. A 2,500 MB video is 2.5 GB, and a 750 MB download is 0.75 GB. Going the other way is a multiplication by 1,000, and every other step on the ladder, from bits to tebibytes, is on the data storage converter.
The trap is the second, older convention. Memory chips and many operating systems count in powers of two, where the step is 1,024 rather than 1,000. The IEC gave those binary units their own names, the mebibyte (MiB) and the gibibyte (GiB), so that 1 GiB = 1,024 MiB = 1,073,741,824 bytes. Windows still uses the binary step but prints the labels MB and GB, which is why the same file can show two different sizes. This converter uses the decimal definition by default; set the Standard switch above to Binary (IEC) to divide MiB by 1,024 instead, and the table further down shows both results side by side.
Step by step
- Take the size in megabytes (MB).
- Divide it by 1,000 to get decimal gigabytes (GB).
- If you need the binary figure Windows shows, divide the byte count by 1,073,741,824 instead.
- Round to two decimal places for everyday use.
See it on a scale
Worked examples
Three disc capacities as they are marketed in megabytes: a CD-R, a single-layer DVD and a single-layer Blu-ray.
700 MB ÷ 1,000 = 0.7 GB
= 0.7 GB
4,700 MB ÷ 1,000 = 4.7 GB
= 4.7 GB
25,000 MB ÷ 1,000 = 25 GB
= 25 GB
How many MB is 1 GB of RAM?
1 GB of RAM is 1,024 MB, because memory is built in powers of two: strictly, it is 1 GiB = 1,024 MiB = 1,073,741,824 bytes.
Memory chips are addressed with binary lines, so every module capacity is a power of two, and JEDEC's memory terminology standard (JESD100B.01) keeps mega and giga as 220 and 230 when they describe semiconductor memory. Flash storage such as SSDs, SD cards and USB sticks follows the SI instead, so a 16 GB flash drive holds 16,000,000,000 bytes while a 16 GB memory module holds 17,179,869,184.
| RAM as sold | Bytes | In MiB | In decimal GB |
|---|---|---|---|
| 4 GB | 4,294,967,296 | 4,096 MiB | 4.29 GB |
| 8 GB | 8,589,934,592 | 8,192 MiB | 8.59 GB |
| 16 GB | 17,179,869,184 | 16,384 MiB | 17.18 GB |
| 32 GB | 34,359,738,368 | 32,768 MiB | 34.36 GB |
| 64 GB | 68,719,476,736 | 65,536 MiB | 68.72 GB |
So a laptop with 16 GB installed really has 17.18 decimal gigabytes of memory. You can see why these numbers are round in base 2 with the binary to decimal converter: 230 is a 1 followed by 30 zeros.
Does Windows or macOS count 1 GB as 1,000 MB?
macOS counts 1 GB as 1,000 MB, while Windows File Explorer counts 1,024 MiB and still prints GB, so a 5,000,000,000-byte folder reads 5 GB on a Mac and 4.66 GB in Windows.
| Where you read the size | 1 GB means | 5,000,000,000 bytes shown as |
|---|---|---|
| Drive and memory-card packaging | 1,000,000,000 bytes | 5 GB |
| macOS (since Mac OS X 10.6) and iOS | 1,000,000,000 bytes | 5 GB |
| Windows File Explorer | 1,073,741,824 bytes | 4.66 GB |
Linux df -h, ls -lh | 1,073,741,824 bytes | 4.7G |
Linux df -H (SI mode) | 1,000,000,000 bytes | 5.0G |
The bytes never change; only the divisor does. When a size really matters, for example when you check whether a disc image fits on a partition, compare exact byte counts, or make sure both figures come from tools that use the same convention.
A quick test tells you which divisor any app uses: look at a drive sold as 256 GB. If the app reports 238.42, it is dividing by 1,024 three times; if it reports 256, it follows the SI.
MB to GB conversion chart
Decimal megabytes converted to decimal gigabytes (1 GB = 1,000 MB), including the power-of-two values such as 1,024 and 4,096 that often appear in memory and app sizes. For terabyte-scale numbers, continue with the GB to TB converter.
| Megabytes (MB) | Gigabytes (GB) |
|---|---|
| 1 MB | 0.001 GB |
| 5 MB | 0.005 GB |
| 10 MB | 0.01 GB |
| 20 MB | 0.02 GB |
| 25 MB | 0.025 GB |
| 50 MB | 0.05 GB |
| 64 MB | 0.064 GB |
| 100 MB | 0.1 GB |
| 128 MB | 0.128 GB |
| 200 MB | 0.2 GB |
| 250 MB | 0.25 GB |
| 256 MB | 0.256 GB |
| 300 MB | 0.3 GB |
| 500 MB | 0.5 GB |
| 512 MB | 0.512 GB |
| 700 MB | 0.7 GB |
| 750 MB | 0.75 GB |
| 1,000 MB | 1 GB |
| 1,024 MB | 1.024 GB |
| 1,500 MB | 1.5 GB |
| 2,000 MB | 2 GB |
| 2,048 MB | 2.048 GB |
| 2,500 MB | 2.5 GB |
| 3,000 MB | 3 GB |
| 4,000 MB | 4 GB |
| 4,096 MB | 4.096 GB |
| 4,700 MB | 4.7 GB |
| 5,000 MB | 5 GB |
| 8,000 MB | 8 GB |
| 8,192 MB | 8.192 GB |
| 8,500 MB | 8.5 GB |
| 10,000 MB | 10 GB |
| 16,384 MB | 16.384 GB |
| 20,000 MB | 20 GB |
| 25,000 MB | 25 GB |
| 32,768 MB | 32.768 GB |
| 50,000 MB | 50 GB |
| 100,000 MB | 100 GB |
Megabytes vs gigabytes: what is the difference?
Both units sit on the same decimal SI ladder, one step of 1,000 apart. The rows below add their byte counts, their binary look-alikes and the places each one turns up.
| Attribute | Megabytes | Gigabytes |
|---|---|---|
| Symbol | MB | GB |
| System | Decimal (SI) | Decimal (SI) |
| Defined as | 1,000 KB | 1,000 MB |
| One unit equals | 0.001 GB | 1,000 MB |
| Exact size in bytes | 1,000,000 bytes (106) | 1,000,000,000 bytes (109) |
| Binary look-alike (IEC) | Mebibyte, MiB = 1,048,576 bytes | Gibibyte, GiB = 1,073,741,824 bytes |
| Prefix defined by | SI prefix mega (106), BIPM SI Brochure | SI prefix giga (109), BIPM SI Brochure |
| Typical everyday sizes | Photos, songs, app updates, email attachments | Phone storage, RAM, data plans, game installs, movies |
| Common confusion | Mb (megabit) is 1/8 of an MB | Windows labels GiB values as GB |
5 key differences
- The gigabyte is exactly 1,000 times the megabyte, the same ratio as between a kilometer and a meter.
- A gibibyte is 73,741,824 bytes larger than a gigabyte, a gap of 7.37%.
- A mebibyte exceeds a megabyte by 48,576 bytes, or 4.86%, so a file always shows a smaller number in MiB than in MB.
- Memory follows JEDEC usage, where an 8 GB module holds 8,589,934,592 bytes, while flash storage follows the SI, where 8 GB is 8,000,000,000 bytes.
- The IEC introduced the names mebibyte and gibibyte in 1998, and IEC 80000-13:2008 now carries them.
The same number in decimal and binary units
A figure like 4,096 can mean decimal megabytes or binary mebibytes, and the gigabyte result changes with the convention. The last column shows how many binary GiB a decimal MB value really is, which is the number Windows displays and labels GB.
| Value | MB to GB (÷ 1,000) | MiB to GiB (÷ 1,024) | MB counted in GiB |
|---|---|---|---|
| 500 | 0.5 GB | 0.4883 GiB | 0.4657 GiB |
| 1,000 | 1 GB | 0.9766 GiB | 0.9313 GiB |
| 1,024 | 1.024 GB | 1 GiB | 0.9537 GiB |
| 2,048 | 2.048 GB | 2 GiB | 1.9073 GiB |
| 4,096 | 4.096 GB | 4 GiB | 3.8147 GiB |
| 4,700 | 4.7 GB | 4.5898 GiB | 4.3772 GiB |
| 8,192 | 8.192 GB | 8 GiB | 7.6294 GiB |
| 10,000 | 10 GB | 9.7656 GiB | 9.3132 GiB |
| 16,384 | 16.384 GB | 16 GiB | 15.2588 GiB |
| 32,768 | 32.768 GB | 32 GiB | 30.5176 GiB |
| 65,536 | 65.536 GB | 64 GiB | 61.0352 GiB |
Why does Windows show fewer gigabytes than the box?
Windows shows fewer gigabytes because it divides the byte count by 1,073,741,824 (1,024 three times) rather than by 1,000,000,000, yet keeps the GB label. A drive sold as 1 TB holds 1,000,000,000,000 bytes, and the maker is using the unit correctly; Windows turns that into 1,000,000,000,000 ÷ 1,073,741,824 = 931.32. It then prints the result with the label GB, although the number is really in GiB. Nothing has gone missing; the same bytes are being measured with a unit that is about 7.37% larger.
The gap shows up on every device. A 256 GB phone reports about 238.42 GB in Windows, and a 512 GB SSD about 476.84 GB. macOS switched to decimal units in version 10.6, so a Mac shows the advertised size, minus whatever the file system and preinstalled software use. Formatting reserves a little extra space for the file table and recovery data, so the free space you see is always a bit lower than either figure.
A quick way to predict the Windows number
Multiply the advertised gigabytes by 0.9313. For example, 128 GB × 0.9313 ≈ 119.2, which matches the 119.21 GiB that a 128 GB USB stick reports. For terabytes the factor drops to 0.9095, because the difference compounds with each prefix step.
How big are common files in MB and GB?
File size is bitrate × duration ÷ 8, because there are 8 bits in a byte. These rows are calculated from the stated bitrates, so real files vary with the encoder and content. Compressed JPEG and HEIC photos are much smaller than the uncompressed figures shown. Streaming bitrates are measured in megabits, which the Gbps to Mbps converter explains.
| File | Calculation | Megabytes | Gigabytes |
|---|---|---|---|
| 4-minute song, MP3 at 128 kbps | 128,000 bit/s × 240 s ÷ 8 | 3.84 MB | 0.00384 GB |
| 4-minute song, MP3 at 320 kbps | 320,000 bit/s × 240 s ÷ 8 | 9.6 MB | 0.0096 GB |
| 4-minute song, CD audio (1,411.2 kbps) | 1,411,200 bit/s × 240 s ÷ 8 | 42.336 MB | 0.04234 GB |
| 12-megapixel photo, uncompressed 24-bit | 12,000,000 px × 3 bytes | 36 MB | 0.036 GB |
| 48-megapixel photo, uncompressed 24-bit | 48,000,000 px × 3 bytes | 144 MB | 0.144 GB |
| 1-minute 4K phone clip at 50 Mbps | 50,000,000 bit/s × 60 s ÷ 8 | 375 MB | 0.375 GB |
| 1-hour 1080p stream at 5 Mbps | 5,000,000 bit/s × 3,600 s ÷ 8 | 2,250 MB | 2.25 GB |
| 1-hour 4K stream at 15 Mbps | 15,000,000 bit/s × 3,600 s ÷ 8 | 6,750 MB | 6.75 GB |
When do you need to convert MB to GB?
You need the conversion whenever sizes quoted in megabytes meet limits quoted in gigabytes, which happens most often with data plans, cloud storage and the free space on a device.
- Mobile data plans: a plan with a 10 GB allowance covers 10,000 MB of traffic. If an app update is 350 MB, it uses 0.35 GB of that allowance.
- Cloud and email limits: upload caps are often quoted in MB while storage plans are sold in GB. Converting both to the same unit tells you how many files will fit.
- Phone and laptop storage: app stores list sizes in MB, but free space is shown in GB. Forty apps averaging 150 MB need 6,000 MB, or 6 GB.
- Video exports: editing tools estimate output in MB, and you need GB to check whether it fits on a USB stick or an SD card.
- Downloads: to estimate time, turn the GB figure into bits and divide by your connection speed. The seconds to minutes converter tidies the result.
Common MB to GB mistakes
- Mixing MB and Mb. A capital B means bytes and a lowercase b means bits. 1 MB = 8 Mb, so a 100 MB file is 800 megabits.
- Dividing by 1,024 with decimal labels. 1,024 is only correct when both sides are binary units (MiB to GiB). Dividing decimal MB by 1,024 gives a number that is neither GB nor GiB.
- Assuming RAM follows the drive convention. A stick sold as 16 GB of RAM actually holds 16 GiB (17,179,869,184 bytes), because memory is built in powers of two.
- Rounding too early. Add file sizes in MB first and convert the total once, otherwise small rounding errors pile up across hundreds of files.
Binary sizes come from the way computers count in base 2; the decimal to binary converter shows why 1,024 is 210.
Sources and further reading
The standards and references behind the numbers on this page. Links open in a new tab.
Standards and official sources
MB to GB FAQs
Short, exact answers to what people ask most.
How many MB are in 1 GB?
There are 1,000 megabytes in one gigabyte under the SI decimal definition used by drive makers, networks and macOS. In binary units there are 1,024 mebibytes (MiB) in one gibibyte (GiB).
Is 1 GB 1,000 MB or 1,024 MB?
By the international standards, 1 GB is 1,000 MB. The 1,024 figure belongs to the binary units MiB and GiB, although Windows and some RAM labels still use it under the GB name.
How many GB is 5,000 MB?
5,000 MB is exactly 5 GB. The same 5,000,000,000 bytes equal about 4.66 GiB, which is what Windows would display.
How many MB is 1.5 GB?
1.5 GB is 1,500 MB in decimal units. In binary units, 1.5 GiB is 1,536 MiB.
Why does my 1 TB drive only show 931 GB?
The drive holds 1,000,000,000,000 bytes, and Windows divides by 1,073,741,824 (1,024 cubed) to get 931.32, which it labels GB. The capacity is all there; the two numbers use different units.
Is MB the same as Mb?
No. MB is megabytes and Mb is megabits, and one byte is 8 bits. So 1 MB equals 8 Mb, and a 25 MB attachment is 200 megabits.
How many GB is 500 MB?
500 MB is 0.5 GB, half a gigabyte. Counted in binary units, the same 500,000,000 bytes are about 0.4657 GiB.
How many GB is 2,500 MB?
2,500 MB equals 2.5 GB. Windows would show the same 2,500,000,000 bytes as about 2.33 GB, because it counts in GiB.
Which is bigger, 1 GB or 500 MB?
1 GB is bigger: it equals 1,000 MB, twice as much as 500 MB.
What comes after a gigabyte?
The terabyte comes next: 1 TB = 1,000 GB = 1,000,000 MB. After that come the petabyte and the exabyte, each 1,000 times larger than the one before.
Related conversions
Decimal prefixes from the BIPM SI Brochure (9th edition); binary prefixes (KiB, MiB, GiB) from IEC 80000-13:2008 and the NIST reference on prefixes for binary multiples; memory capacity usage from JEDEC JESD100B.01; macOS and iOS storage reporting from Apple support documentation; Linux size output from the GNU coreutils manual. Last updated . How we verify our numbers.