Data Storage Converter
Bytes, KB, MB, GB and TB.
Convert a data size
Results update as you type.
100 GB equals
100,000 MB
MB = GB × 1,000
100 GB in every unit
Decimal (SI): powers of 1,000
- kB100,000,000
- MB100,000
- GB100
- TB0.1
- PB0.0001
- EB1e-7
- ZB1e-10
- YB1e-13
Binary (IEC): powers of 1,024
- KiB97,656,250
- MiB95,367.43164
- GiB93.13225746
- TiB0.09094947018
- PiB0.00008881784197
- EiB8.67361738e-8
- ZiB8.470329473e-11
- YiB8.271806126e-14
Bits and bytes
- bit800,000,000,000
- byte100,000,000,000
Bits (decimal)
- kbit800,000,000
- Mbit800,000
- Gbit800
Download and transfer time
How long a file takes at a given connection speed.
Estimated time
0:05:20
5 min 20 s (320 seconds) to move 4,000,000,000 bytes at 100,000,000 bits per second.
Network speeds are quoted in bits per second and 1 byte = 8 bits. This is the best case: it ignores protocol overhead, latency, congestion and drive speed, so real downloads usually take longer.
Why does my 1 TB drive show 931 GB?
Enter the size on the box and see what a Windows-style display reports.
A 1 TB drive is shown as
931.32 GB
That is 931.3225746 GiB (binary), about 6.9% lower than the number on the box. The drive holds 1,000,000,000,000 bytes either way.
Drive makers count in decimal (1 GB = 1,000,000,000 bytes). Windows-style displays count in binary (1 GiB = 1,073,741,824 bytes) but print the label as GB. Nothing is missing: the same number of bytes is shown in a bigger unit.
| Advertised | Shown by Windows-style display | In GiB |
|---|---|---|
| 128 GB | 119.21 GB | 119.21 |
| 256 GB | 238.42 GB | 238.42 |
| 500 GB | 465.66 GB | 465.66 |
| 512 GB | 476.84 GB | 476.84 |
| 1 TB | 931.32 GB | 931.32 |
| 2 TB | 1.82 TB | 1,862.65 |
| 4 TB | 3.64 TB | 3,725.29 |
Common data conversions
| Convert | Result |
|---|---|
| 1 GB to MB | 1,000 MB |
| 1 GB to MiB | 953.6743164 MiB |
| 1 GiB to MiB | 1,024 MiB |
| 100 GB to MB | 100,000 MB |
| 100 GB to MiB | 95,367.43164 MiB |
| 200 GB to MiB | 190,734.8633 MiB |
| 200 GB to MB | 200,000 MB |
| 1 ZB to GB | 1,000,000,000,000 GB |
| 1 TB to GB | 1,000 GB |
| 1 TB to GiB | 931.3225746 GiB |
| 1 TiB to GB | 1,099.511628 GB |
| 1,000 MB to GB | 1 GB |
| 500 MB to GB | 0.5 GB |
| 1,000,000,000 byte to GB | 1 GB |
| 1 GB to byte | 1,000,000,000 byte |
| 1 PB to TB | 1,000 TB |
| 1 MiB to KiB | 1,024 KiB |
| 1 byte to bit | 8 bit |
Data Storage Unit Conversion: Bytes, KB, MB, GB, TB and KiB, MiB, GiB
Enter a size, pick the units to convert from and to, and the converter shows the answer straight away together with the formula and the same size in every unit, split into decimal (SI) and binary (IEC) columns. It works for everyday jobs like turning GB into MB or bytes into GB, and for larger units all the way up to zettabytes and yottabytes. Calculations use exact arithmetic, so a figure like 0.1 GB is exactly 100 MB.
Below the converter, the transfer-time panel estimates a download from the file size and your connection speed, and the drive panel explains why a drive shows less capacity than the number printed on the box.
Decimal (SI) and Binary (IEC) Units
Binary (IEC): 1 KiB = 1,024 bytes, 1 MiB = 1,024 KiB, 1 GiB = 1,024 MiB, 1 TiB = 1,024 GiB
Across systems: convert to bytes first. For example MiB = GB × 1,000,000,000 ÷ 1,048,576.
Worked Examples
100 GB to MB. In decimal, 100 GB = 100,000 MB. As binary mebibytes, 100 GB is 95,367.43164 MiB, because each MiB is a little larger than a MB. And 100 GiB is exactly 102,400 MiB. The converter flags it when your answer crosses between the two systems.
A 4 GB file at 100 Mbps. 4 GB is 4,000,000,000 bytes, which is 32,000,000,000 bits. Divided by 100,000,000 bits per second, that is 320 seconds, or 5 min 20 s (0:05:20). At 1 Gbps the same file would take 32 seconds. This ignores overhead, so allow extra time.
A 1 TB drive. 1,000,000,000,000 bytes ÷ 1,073,741,824 = 931.3225746 GiB, the figure many Windows-style displays show as “931 GB”. It is about 6.87% lower than the number on the box, purely because of the unit.
Download Time and Connection Speed
Download time is the file size in bits divided by the speed in bits per second. A speed in megabytes per second (MB/s) is 8 times a speed in megabits per second (Mbps), so 100 MB/s is 800 Mbps and 100 Mbps is 12.5 MB/s. Real transfers usually run below the headline speed because of overhead, distance, congestion and the speed of the drive or server at each end.
Frequently Asked Questions
- How do I do a GB to MB conversion, and what is 1 GB in MB?
- In decimal (SI), the units storage makers and most websites use, 1 GB = 1,000 MB. In binary, 1 GiB = 1,024 MiB. So 1 GB to MB is 1,000, while 1 GiB to MiB is 1,024. Always check whether the unit is written GB or GiB, because the gap is about 2.4% at the kilo step and grows with every step up (about 7.4% by the giga step).
- How do I convert 100GB to MB?
- In decimal, multiply by 1,000: 100 GB = 100,000 MB. In binary, 100 GiB = 102,400 MiB (multiply by 1,024). If you want 100 GB, the decimal gigabytes on a box or plan, expressed in binary mebibytes, the answer is 95,367.43164 MiB.
- What is 200GB in MiB?
- 200 GB (decimal) is 200,000,000,000 bytes. A MiB is 1,048,576 bytes, so 200 GB = 200,000,000,000 ÷ 1,048,576 = 190,734.8633 MiB. The formula is MiB = GB × 953.6743164. If you meant 200 GiB, that is simply 204,800 MiB.
- How many gigabytes are in a zettabyte (zettabytes to gigabytes)?
- 1 zettabyte (ZB) = 1,000,000,000,000 GB, which is one trillion gigabytes (1 ZB = 1,000,000,000 TB). In bytes that is 1 followed by 21 zeros. In binary, a zebibyte (ZiB) is a little larger, at 2^70 bytes.
- What are the storage units, and how does a storage unit conversion work?
- The smallest unit is the bit, and 8 bits make a byte. Decimal (SI) units then step by 1,000: kB, MB, GB, TB, PB, EB, ZB, YB. Binary (IEC) units step by 1,024: KiB, MiB, GiB, TiB, PiB, EiB, ZiB, YiB. To convert, move one step up by dividing or one step down by multiplying, staying within the same system; the converter's all-units table shows every unit at once.
- How do I convert bytes to GB, or MB to GB?
- Divide bytes by 1,000,000,000 to get decimal gigabytes: 1,000,000,000 bytes = 1 GB. Divide megabytes by 1,000: 1,000 MB = 1 GB and 500 MB = 0.5 GB. For binary gibibytes divide bytes by 1,073,741,824 instead, so 1 GB is 0.9313225746 GiB.
- Why is there a difference in data unit conversion between GB and GiB?
- Two systems share similar names. SI prefixes (kilo, mega, giga) mean powers of 1,000, while IEC prefixes (kibi, mebi, gibi) mean powers of 1,024. 1 GB is 1,000,000,000 bytes and 1 GiB is 1,073,741,824 bytes. Some operating systems and older software use KB, MB and GB to mean the binary sizes, which is where the confusion comes from.
- Why does my 1 TB drive show 931 GB?
- The maker counts a terabyte as 1,000,000,000,000 bytes. Windows-style displays count in binary, where 1 GiB is 1,073,741,824 bytes, so the same drive is 931.3225746 GiB, shown with the label GB. No space is missing: it is the same number of bytes in a bigger unit. A 500 GB drive similarly shows as 465.66 GB, and a 2 TB drive as 1.82 TB.
- How long does a 4 GB download take?
- Internet speeds are quoted in bits per second and a byte is 8 bits. A 4 GB file is 32,000,000,000 bits, so at 100 Mbps it takes 320 seconds (5 min 20 s), and at 1 Gbps it takes 32 seconds. Real downloads are usually slower because of protocol overhead and network congestion.