What is bit?
A bit is the smallest unit of digital information, representing a value of either 0 or 1. It is used to express network bandwidth, signal data rates, and low-level binary data in computing and telecommunications.
Real-world uses
Bits are the fundamental unit of data transmission. Network speeds (Wi-Fi, fibre broadband, mobile data) are measured in bits per second (bps and its multiples). Colour depth in digital displays is expressed in bits per channel (8-bit colour = 256 shades per channel). Audio resolution is described in bits (16-bit CD, 24-bit studio audio).
History
The term "bit" (contraction of "binary digit") was coined by mathematician John Tukey in 1947. Claude Shannon formalised the concept in his landmark 1948 paper "A Mathematical Theory of Communication," establishing information theory and defining the bit as the fundamental unit of information.
Common mistakes
Confusing bits with bytes — 8 bits = 1 byte. A "100 Mbps" internet connection transfers 100 megabits, or 12.5 megabytes, per second. Capitalisation matters: "b" = bit, "B" = byte, so "Mb" is not the same as "MB".
What is megabyte (decimal)?
A megabyte in the decimal system is a data unit equal to 1,000 kilobytes. It is commonly used by storage manufacturers, internet service providers, and operating systems to express file sizes and storage capacities.
Real-world uses
Megabytes are the everyday unit for typical file sizes: photos (2–10 MB), MP3 songs (3–10 MB), mobile app downloads (10–100 MB), and email attachments. Mobile data plans are often described in megabytes or gigabytes. A minute of compressed video at 720p is roughly 40–80 MB.
History
The megabyte became a practical everyday unit in the 1980s as personal computers began shipping with hard drives in the megabyte range. Floppy disks (1.44 MB), early hard drives (10–40 MB), and CD-ROMs (650 MB) all popularised the unit during this era.
Common mistakes
The same decimal vs. binary ambiguity as kilobytes applies: 1 MB = 1,000,000 bytes (SI) vs. 1 MB = 1,048,576 bytes (legacy binary). Hard drive manufacturers use the decimal definition, so a "500 MB" drive shows slightly less in an OS that uses binary counting. The binary equivalent is the mebibyte (MiB).
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.
Worked examples
1 bit = 1.250000e-07 megabyte (decimal)
1 megabyte (decimal) = 1,000,000 byte
How to convert bit to megabyte (decimal)
To convert bit to megabyte (decimal), multiply the value by 1.250000e-07.
To convert megabyte (decimal) back to bit, multiply by 8,000,000.
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.
Quick reference: bit to megabyte (decimal)
| bit | megabyte (decimal) |
|---|---|
| 0.1 | 1.250000e-08 |
| 0.5 | 6.250000e-08 |
| 1 | 1.250000e-07 |
| 2 | 2.500000e-07 |
| 5 | 6.250000e-07 |
| 10 | 0.00000125 |
| 25 | 0.00000313 |
| 50 | 0.00000625 |
| 100 | 0.0000125 |
| 250 | 0.00003125 |
| 500 | 0.0000625 |
| 1,000 | 0.000125 |
Common values
| bit | megabyte (decimal) | |
|---|---|---|
| A text email | 40,000 bit | 0.005 megabyte (decimal) |
| An MP3 song (4 min) | 32,000,000 bit | 4 megabyte (decimal) |
| A smartphone photo | 40,000,000 bit | 5 megabyte (decimal) |
| An HD movie | 4.000000e+10 bit | 5,000 megabyte (decimal) |
| A full hard drive | 8.000000e+12 bit | 1,000,000 megabyte (decimal) |
Available Data units
More bit conversions
- Convert bit to byte
- Convert bit to kilobyte (decimal)
- Convert bit to megabyte (decimal)
- Convert bit to gigabyte (decimal)
- Convert bit to terabyte (decimal)
- Convert bit to kibibyte (binary)
- Convert bit to mebibyte (binary)
- Convert bit to gibibyte (binary)
- Convert bit to tebibyte (binary)
Assumption: both decimal (kB, MB, GB, TB) and binary (KiB, MiB, GiB, TiB) units are included.