BitThe smallest unit of data, representing a single binary value of 0 or 1.
Byte (B)A group of 8 bits; enough to store a single ASCII character.
Kilobyte (KB)1,000 bytes (SI) or 1,024 bytes (binary/KiB), roughly the size of a short text file.
Gigabyte (GB)Approximately one billion bytes; a typical HD movie is 4–5 GB.
Petabyte (PB)One quadrillion bytes; large cloud providers store data at the petabyte scale.
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Real-World Examples
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Photo Library
Input: 256 GB
Result
274,877,906,944 bytes (binary)
274,877,906,944 bytes (binary) — enough for roughly 64,000 high-resolution photos
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Internet Speed
Input: 100 Mbps
Result
12.5 MB/s
12.5 MB/s — megabits per second divided by 8 gives megabytes per second
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Data Storage Unit Scale
Unit
Bytes (Decimal)
Bytes (Binary)
Example
1 KB
1,000
1,024
Short email
1 MB
1,000,000
1,048,576
A high-res photo
1 GB
10&sup9
1,073,741,824
HD movie episode
1 TB
10¹²
1,099,511,627,776
Large external drive
1 PB
10¹&sup5
1,125,899,906,842,624
Enterprise data warehouse
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Binary vs. Decimal: Why Your Drive Seems Smaller
The Two Counting Systems
Storage manufacturers label drives using SI (decimal) prefixes where 1 GB = 1,000,000,000 bytes. Operating systems, however, count in binary where 1 GiB = 1,073,741,824 bytes. This discrepancy means a drive advertised as 1 TB shows roughly 931 GiB in your file manager. Neither side is wrong; they simply use different base systems.
Practical Implications
The gap widens with larger drives. A 4 TB drive appears as about 3.63 TiB. When planning storage for backups or media servers, always budget using the binary figure your OS reports. For network speeds, remember that ISPs quote megabits (Mb) while downloads display megabytes (MB)—divide by eight to reconcile the two.
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Frequently Asked Questions
What is the difference between MB and MiB?+
MB (megabyte) uses the decimal system where 1 MB equals 1,000,000 bytes. MiB (mebibyte) uses the binary system where 1 MiB equals 1,048,576 bytes. Storage manufacturers use MB while operating systems often report in MiB.
Why does my hard drive show less space than advertised?+
Drive manufacturers measure capacity in decimal units (1 TB = 1 trillion bytes), but your operating system displays space in binary units (1 TiB = 1,099,511,627,776 bytes). This discrepancy makes a 1 TB drive appear as roughly 931 GiB.
How do I convert between bits and bytes?+
Enter your value and select the source unit. There are 8 bits in 1 byte, so to convert manually, divide bits by 8 to get bytes or multiply bytes by 8 to get bits. Internet speeds are typically measured in bits per second.
What is the largest data storage unit supported?+
This converter supports units up to yottabytes (YB) and yobibytes (YiB). A yottabyte equals 1 septillion bytes, or roughly the amount of data generated globally in several years.
When should I use binary vs decimal units?+
Use binary units (KiB, MiB, GiB) when working with RAM, file systems, and programming contexts. Use decimal units (KB, MB, GB) for storage capacity labels, network speeds, and telecommunications specifications.