Data Storage Converter
Convert between bits, bytes, decimal GB and TB and binary GiB and TiB, see why a 1 TB drive shows as 931 GB, and how long a file takes at a given speed.
Result
Converted: 931.3225746 GiB
Exact: every prefix is a power of ten or of two.
- In bytes
- 1,000,000,000,000
- In decimal prefixes
- 1 TB
- In binary prefixes
- 931.323 GiB
- In bits
- 8,000,000,000,000
https://calcgallery.com/notation-conversions/data-storage-converter-calculator/
Unit conversions follow from exact definitions and published notation rules. Sizes follow published standards and are approximate: makers grade their own, so check their chart. Figures are rounded only for display. Read the full disclaimer
How to use the Data Storage Converter
- Enter an amount and choose its unit, then the unit to convert to.
- Decimal units (kB, MB, GB, TB) and binary units (KiB, MiB, GiB, TiB) are listed separately, because they are different sizes.
- Add a connection speed to see how long the amount takes to transfer.
Two families of prefixes
decimal (SI): 1 kB = 10³ 1 MB = 10⁶ 1 GB = 10⁹ 1 TB = 10¹² bytesbinary (IEC): 1 KiB = 2¹⁰ 1 MiB = 2²⁰ 1 GiB = 2³⁰ 1 TiB = 2⁴⁰ bytesAt each step the binary unit is larger, and the gap grows: 2.4% at kilo, 4.9% at mega, 7.4% at giga and 10% at tera. That is why the difference between what a drive’s box says and what a computer reports seems to get worse with bigger drives.
Bits and bytes
A byte is 8 bits. File sizes and storage are counted in bytes (capital B), network speeds in bits (small b). To find how long a transfer takes, turn the size into bits and divide by the speed:
transfer time = size in bytes × 8 ÷ speed in bits per secondReal transfers take somewhat longer than this, because of protocol overhead and because connections rarely run at their full rated speed.
With your numbers
- 1 TB = 10¹² bytes; 1 TiB = 2⁴⁰ = 1,099,511,627,776 bytes; 1 byte = 8 bits
Quick reference
Exact: every prefix is a power of ten or of two.
| Example | Converted |
|---|---|
| 1 TB drive in GiB | 931.3225746 GiB |
| 1 TiB in bytes | 1099511628000 B |
| 1 GiB in MiB | 1024 MiB |
| 1 GB in MB | 1000 MB |
| 100 Mbit in MB | 12.5 MB |
| 4.7 GB at 100 Mbps | 4.377216101 GiB |
Common questions about the Data Storage Converter
- Why does my 1 TB drive show as 931 GB?
- The drive maker counts in powers of ten: 1 TB is 1,000,000,000,000 bytes. Many operating systems count in powers of two, where the unit is 2³⁰ = 1,073,741,824 bytes, and divide by that: 10¹² ÷ 2³⁰ = 931.3. They label the result GB, but it is really GiB, gibibytes. Nothing is missing; the same number of bytes is being measured with a larger unit.
- What is the difference between a GB and a GiB?
- A gigabyte, GB, is 10⁹ bytes, the SI meaning of giga. A gibibyte, GiB, is 2³⁰ bytes, about 7.4% more. The binary prefixes kibi, mebi, gibi and tebi were defined by the IEC precisely so that the two would stop being confused, though many programs still write GB for both.
- How many megabytes per second is 100 Mbps?
- 12.5. Network speeds are quoted in bits per second, and there are 8 bits in a byte, so 100 megabits per second moves 12.5 megabytes each second. A 4.7 GB file therefore takes 376 seconds, about 6¼ minutes, not the 47 seconds that confusing the two would suggest.
- Is a kilobyte 1,000 or 1,024 bytes?
- Strictly, a kilobyte (kB) is 1,000 bytes and a kibibyte (KiB) is 1,024. Older usage, and some software today, still calls 1,024 bytes a kilobyte, so check which one a figure means when it matters.