A megabit is a metric unit of digital information equal to one million bits (1,000,000 bits). It is commonly written as Mbit or Mb and forms the basis for many data-rate and capacity measurements in networking and telecommunications. Because a bit is the smallest unit of digital data, megabits are convenient for expressing medium-scale quantities such as modem speeds, streaming bandwidths, and link capacities.

In the International System of Units (SI) the prefix "mega" denotes one million (10^6), so a megabit is strictly 1,000,000 bits. Converting to bytes (where 1 byte = 8 bits) gives 125,000 bytes, or 0.125 decimal megabytes (MB). By contrast, binary-based prefixes exist: a mebibit equals 2^20 bits (1,048,576 bits) and is a different quantity. These distinctions matter when precision is required.

Uses and practical meaning

Megabits per second (abbreviated Mb/s or Mbps) is the standard way to advertise network and internet connection speeds. Higher Mbps values indicate the ability to transfer more bits each second, which typically reduces download times and improves the quality of streamed audio and video. Hardware specifications, throughput tests, and many consumer plans use megabits to express capacity rather than megabytes.

Common confusions and clarifications

  • Mb vs MB: "Mb" (megabit) is eight times smaller than "MB" (megabyte). Mixing these can lead to mistaken expectations about speed or capacity.
  • Decimal vs binary: SI megabit = 1,000,000 bits, while the binary mebibit = 1,048,576 bits; the difference is modest but relevant for technical calculations.
  • Rates vs sizes: ISPs usually quote connection speed in Mbps, whereas file sizes on storage devices are commonly given in megabytes or gibibytes.

For practical examples, 10 Mbps corresponds to a maximum theoretical transfer of 1.25 megabytes per second (10,000,000 bits / 8). When comparing plans, announcements, or device specs, check whether quantities use bits or bytes and whether prefixes follow decimal or binary conventions. For further background and technical references, see additional resources.