How to use the Data Storage Converter
- Enter the size you want to convert.
- Choose the unit you have and the unit you want. Decimal units are kB, MB, GB, TB; binary units are KiB, MiB, GiB, TiB.
- Read the result and the conversion factor.
- Use the reference table for common sizes.
Formula used
Decimal units use powers of 1000 (1 MB = 1,000,000 B). Binary units use powers of 1024 (1 MiB = 1,048,576 B). 1 byte = 8 bits.
Worked example
Here is the Data Storage Converter worked through with the example values shown above, so you can check each step by hand.
| Inputs | |
|---|---|
| Value | 1 |
| From | Terabytes (TB) |
| To | Gibibytes (GiB) |
| Result | |
| Converted value | 931.32257 |
| Conversion rate | 1 TB = 931.32257 GiB |
Quick reference table
Common values converted with the units selected above.
| From | To |
|---|---|
| 1 TB | 931.32257 GiB |
| 8 TB | 7,450.5806 GiB |
| 100 TB | 93,132.257 GiB |
| 256 TB | 238,418.58 GiB |
| 512 TB | 476,837.16 GiB |
| 1,000 TB | 931,322.57 GiB |
Decimal and binary units
In the decimal (SI) system, 1 kB is 1,000 bytes, 1 MB is 1,000,000 bytes, 1 GB is 1,000,000,000 bytes and 1 TB is 10¹² bytes. Drive makers and network speeds use these units. In the binary system, 1 KiB is 1,024 bytes, 1 MiB is 1,048,576 bytes, 1 GiB is 1,073,741,824 bytes and 1 TiB is about 1.0995 × 10¹² bytes.
The gap grows with size: 1 GB is 0.9313 GiB, which is about 7% smaller, while 1 TB is 0.9095 TiB, about 9% smaller.
Why a 1 TB drive shows about 931 GB
A drive sold as 1 TB holds 1,000,000,000,000 bytes. Some operating systems divide by 1,024 three times and label the result “GB”, although it is really GiB. That gives 931.32, so the drive appears to be about 931 GB. Nothing is missing: the same number of bytes is shown in a different unit. Some systems, including macOS, now use decimal units and show the full 1 TB.
A 256 GB phone is 238.4 GiB, and a 512 GB drive is 476.8 GiB. Part of the space is also used by the system and by formatting.
Bits versus bytes
A byte is 8 bits. Storage is measured in bytes (capital B) while internet speeds are measured in bits per second (lowercase b). A 100 megabit per second connection moves at most 12.5 megabytes per second: 12.5 MB each second. To download a 1 GB file at 100 Mbps takes at least 80 seconds, and in practice longer.
So 1 byte is 8 bits, and 1 MB is 8,000,000 bits.
Typical file sizes
A page of plain text is a few kilobytes, a photo from a phone is roughly 2 to 6 MB, a three-minute song is about 3 to 10 MB depending on quality, and an hour of HD video can use 1 to 3 GB. Games and operating system installs often take tens of gigabytes. These are rough figures and depend on format and quality.
To see how many photos fit on a drive, divide its capacity by the average file size. A 128 GB card holds about 32,000 photos of 4 MB each, before the system uses any space.
Frequently asked questions
Why does my 1 TB drive show about 931 GB?
Makers count 1 TB as 1,000,000,000,000 bytes, while many operating systems show sizes in binary units (GiB), where 1 TB is about 931 GiB.
Is a megabit the same as a megabyte?
No. A byte is 8 bits, so a megabyte is eight times a megabit. Internet speeds are often quoted in megabits per second.
What is a GiB?
A gibibyte: 1,073,741,824 bytes (1024³). It is the binary equivalent of the decimal gigabyte.
How many MB are in a GB?
1,000 MB in a decimal GB, or 1,024 MiB in a binary GiB.
How many bytes are in a kilobyte?
1,000 bytes in a decimal kilobyte (kB) and 1,024 bytes in a binary kibibyte (KiB).
Why are internet speeds in bits?
It is a convention from networking, where data is sent bit by bit. Divide by 8 to get bytes per second.
This calculator gives estimates for information only. Actual figures from a bank, employer, tax authority or doctor may differ. It is not financial, tax, legal or medical advice.