Bytes, bits, MB and MiB: why your drive has “less” space
The difference between decimal and binary units, and between megabits and megabytes, with examples.
Digital storage converter
Convert bytes, KB, MB, GB and their binary equivalents.
Runs in your browser
1 kB = 1,000 bytes, while 1 KiB = 1,024 bytes. 1 byte = 8 bits.
| B | 1,000,000,000,000 |
|---|---|
| kB | 1,000,000,000 |
| MB | 1,000,000 |
| GB | 1,000 |
| TB | 1 |
| PB | 0.001 |
| KiB | 976,562,500 |
|---|---|
| MiB | 953,674.32 |
| GiB | 931.32257 |
| TiB | 0.9094947 |
| PiB | 0.00088817842 |
| bit | 8,000,000,000,000 |
|---|---|
| kbit | 8,000,000,000 |
| Mbit | 8,000,000 |
| Gbit | 8,000 |
Estimated download time
22 h 13 min 20 s
Theoretical speed; in practice it's usually a bit lower due to latency and protocol overhead.
What it does: Digital storage converter
Why does a 1 TB drive show up as 931 GB on your computer? Because manufacturers use decimal units (1 GB = 1,000,000,000 bytes) while many operating systems show binary units (1 GiB = 1,073,741,824 bytes) but still call them “GB”.
This tool converts any size between both systems and to bits, and estimates how long it would take to download at a given connection speed.
How to use it
- Enter the amount and choose its unit.
- See the equivalent in decimal, binary and bit units.
- Enter your speed in Mbit/s to estimate the download time.
Examples
Hard drive
1 TB = 931.32 GiB: no space is missing, it's just a different unit.
Game download
50 GB on a 100 Mbit/s connection takes about 66 minutes in ideal conditions.
Limits, formulas and assumptions
- SI (decimal) prefixes: kB, MB, GB, TB, PB, in powers of 1,000.
- IEC (binary) prefixes: KiB, MiB, GiB, TiB, PiB, in powers of 1,024.
- Internet speeds are quoted in bits per second (Mbit/s), not bytes: 100 Mbit/s is 12.5 MB/s.
- Windows shows binary units with decimal names (“GB”); macOS and iOS use true decimal units.
Frequently asked questions
Is a MB 1,000 or 1,024 KB?
By the standard, 1 MB = 1,000 kB and 1 MiB = 1,024 KiB. In practice many programs say “MB” when they mean MiB.
Why is my download slower than my plan's speed?
Because the speed is in megabits: divide by 8 to get megabytes per second, and allow a little for protocol and network overhead.
What is a byte?
The basic unit of storage: 8 bits, enough to represent one ASCII character.
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