gigabyte (decimal) (GB)
1 gigabyte (decimal) = 1.000000e+09 bytes
What is gigabyte (decimal)?
A gigabyte in the decimal system is a data unit equal to 1,000 megabytes. It is widely used to express storage device capacity, RAM size, file sizes, and data transfer quotas in consumer electronics and networking.
Notes: Decimal prefix
Real-world uses
Gigabytes are the standard unit for smartphone storage (64–512 GB), laptop hard drives (256 GB–2 TB), monthly mobile data plans (5–100 GB), and video files. A 4K video file runs about 50–100 GB per hour uncompressed, or 4–10 GB per hour when compressed (H.264/H.265).
History
The gigabyte became the dominant consumer storage unit in the late 1990s and 2000s as hard drive capacities surpassed the megabyte range. Flash storage in phones and USB drives in the gigabyte range popularised the term with mainstream consumers in the 2000s–2010s.
Common mistakes
The decimal vs. binary discrepancy is most visible with gigabytes: 1 GB = 1,000,000,000 bytes (SI/marketing), while the OS may display the same drive capacity as ~0.93 GiB. A "256 GB" phone shows roughly 238 GiB available. The binary equivalent is the gibibyte (GiB).
When is this conversion used?
Operating systems and storage manufacturers use different base systems (binary vs decimal), which is why a '1 TB' drive shows less than 1 TB in your file manager. Understanding this conversion prevents confusion about available storage.
How to convert gigabyte (decimal) to byte
To convert gigabyte (decimal) to byte, multiply the value by 1.000000e+09.
Conversion formula (from base unit)
x * 1000000000.0
Measurement standards
The International Electrotechnical Commission (IEC 80000-13) defines binary prefixes: 1 KiB = 1,024 bytes, 1 MiB = 1,048,576 bytes. The SI decimal prefixes (kB = 1,000 bytes, MB = 1,000,000 bytes) apply to data units as they do to all SI quantities.
Did you know?
By 2025, the global datasphere is estimated to reach 181 zettabytes — roughly 181 trillion gigabytes. If stored on standard Blu-ray discs, the stack would reach from Earth to Mars and back over 20 times.
| gigabytes (decimal) | bytes |
|---|---|
| 0.1 | 100,000,000 |
| 0.5 | 500,000,000 |
| 1 | 1.000000e+09 |
| 2 | 2.000000e+09 |
| 5 | 5.000000e+09 |
| 10 | 1.000000e+10 |
| 25 | 2.500000e+10 |
| 50 | 5.000000e+10 |
| 100 | 1.000000e+11 |
| 250 | 2.500000e+11 |
| 500 | 5.000000e+11 |
| 1,000 | 1.000000e+12 |
Common values
| gigabytes (decimal) | bytes | |
|---|---|---|
| A text email | 0.000005 gigabytes (decimal) | 5,000 bytes |
| An MP3 song (4 min) | 0.004 gigabytes (decimal) | 4,000,000 bytes |
| A smartphone photo | 0.005 gigabytes (decimal) | 5,000,000 bytes |
| An HD movie | 5 gigabytes (decimal) | 5.000000e+09 bytes |
| A full hard drive | 1,000 gigabytes (decimal) | 1.000000e+12 bytes |
Full gigabyte (decimal) conversion table
| Unit | Value | Factor |
|---|---|---|
| byte | 1 GB = 1.000000e+09 B | × 1.000000e+09 |
| kilobyte (decimal) | 1 GB = 1,000,000 kB | × 1,000,000 |
| megabyte (decimal) | 1 GB = 1,000 MB | × 1,000 |
| terabyte (decimal) | 1 GB = 0.001 TB | × 0.001 |
| bit | 1 GB = 8.000000e+09 b | × 8.000000e+09 |
| kibibyte (binary) | 1 GB = 976,562.5 KiB | × 976,562.5 |
| mebibyte (binary) | 1 GB = 953.67431641 MiB | × 953.67431641 |
| gibibyte (binary) | 1 GB = 0.93132257 GiB | × 0.93132257 |
| tebibyte (binary) | 1 GB = 0.00090949 TiB | × 0.00090949 |