megabyte

IPA/ˈmeɡəbaɪt/
KK[mˈɛɡəbˌaɪt]IPA/ˈmeɡəbaɪt/

megabyte — noun

  • megabytesingular
  • megabytesplural

1. a unit for measuring digital information in the binary system used by computers.

1.nounB1
Definition

a unit for measuring digital information in the binary system used by computers. One megabyte equals 1,048,576 bytes (2²⁰), which is 1024 multiplied by 1024. RAM, processor cache, and system firmware are typically described using this binary value.

Example

Jiwoo added 256 megabytes of video memory to the old laptop for basic gaming.

number + megabytes + of + noun for describing capacity

Iker checked the system menu and saw the router had only 16 megabytes of flash memory.

Common collocations
  • megabytes of RAM
  • megabytes of memory
  • megabytes of cache
  • megabytes of video memory
  • megabytes of flash storage
Synonyms
  • mebibyte

    the precise International Electrotechnical Commission (IEC) name for 1,048,576 bytes; used in technical documents but rare in everyday language

  • MiB

    the abbreviation for mebibyte; found in Linux system monitors and scientific computing

Grammar Patterns

number + megabytes + of + noun

Usage Note

This binary definition (2²⁰ = 1,048,576 bytes) is the standard used for RAM and system memory. It differs from the decimal definition (sense 2) used by storage drive manufacturers. The precise name for this binary unit is mebibyte (MiB), though the term megabyte (MB) remains far more common in everyday use.

Common Mistakes

I downloaded a 5-megabit file' (when the file is 5 MB).
I downloaded a 5-megabyte file.
One megabyte equals 8 megabits; confusing the two changes the size by a factor of 8.
My hard drive has 500 megabytes of storage' (using the binary meaning).
Check the manufacturer's labelling
hard drives use the decimal megabyte (1,000,000 bytes), which is slightly smaller than the binary megabyte (1,048,576 bytes).

2. a unit for measuring data storage capacity in the decimal system. One megabyte e

2.nounB1
Definition

a unit for measuring data storage capacity in the decimal system. One megabyte equals 1,000,000 bytes (10⁶), which is 1000 kilobytes. Hard drives, USB drives, and advertised file sizes are most often given in this decimal value.

Example

Mayumi backed up the photos on her phone and freed 300 megabytes of storage space.

number + megabytes + of + noun for freed/used storage

Ishaan compressed a video file from 200 megabytes down to 40 megabytes for email.

from + number + megabytes + down to + number + megabytes (change in size)

Common collocations
  • megabytes of storage
  • megabytes of space
  • megabytes of data
  • megabytes of capacity
  • megabytes per second
Synonyms
  • million bytes

    an informal phrase that makes the decimal value explicit

Grammar Patterns

number + megabytes + of + noun

Usage Note

Storage manufacturers and most operating system file managers use this decimal definition (1 MB = 1,000,000 bytes) when displaying capacity. However, some operating systems (notably older versions of Windows) show capacity using the binary definition, which can confuse users who see a smaller number than the drive's advertised size.

Common Mistakes

My new 500 GB hard drive shows only 465 GB on my computer — it must be broken.
The difference is normal: drive makers use decimal gigabytes (1 GB = 1,000,000,000 bytes) while the OS may report in binary gigabytes (1 GB = 1,073,741,824 bytes). The same rounding happens with megabytes.
A megabyte is always 1,000,000 bytes.
A megabyte can mean either 1,000,000 bytes (decimal) or 1,048,576 bytes (binary) depending on context. The IEC now recommends 'mebibyte' (MiB) for the binary value to avoid confusion.

Word family

Synonym discussion

Sense: noun/1

A megabyte (MB) sits between a kilobyte (KB) and a gigabyte (GB) in size. One kilobyte equals roughly 1000 bytes — enough for a short email. A megabyte holds about a million bytes, or a few high-resolution photos. A gigabyte is about 1000 megabytes, enough for a full-length movie. Megabyte should not be confused with megabit (Mb): one byte is 8 bits, so an 8 megabit connection transfers data at roughly 1 megabyte per second. The mebibyte (MiB) is the precise binary equivalent of the traditional megabyte (1 MiB = 1,048,576 bytes), but most consumers and product labels still use "megabyte" for both binary and decimal values, causing the well-known capacity gap between advertised and actual storage sizes.

kilobyte ↗gigabytemebibytemegabit

Common collocations

Nouns

Adverbs

Phrases

  • megabytes of data
  • megabytes of storage
  • megabytes of memory
  • megabytes per second
  • in megabytes
  • megabytes in size

Prepositions

Etymology

GreekEnglish

The word 'megabyte' was formed in the early days of computing by combining 'mega-', meaning 'large' or 'one million' (from Greek μέγας, megas), with 'byte', a unit of digital information coined at IBM in 1956. The spelling was changed from 'bite' (a natural choice for a small unit of data) to 'byte' to avoid confusion with 'bit'. The prefix 'mega-' created an immediate ambiguity: in computer memory it was taken as 2²⁰ (1,048,576) because memory sizes are naturally powers of two, but in storage contexts it followed the metric system as 10⁶ (1,000,000). This dual meaning persists today.

First known use

1965

1965, in the meaning defined above