MB
MB (abbreviation) means Megabyte: a unit of digital storage equal to one million bytes, or 1,048,576 bytes when counted in binary. Used for file sizes, memory and data allowances. Example: “The photo is about 4 MB, so it should attach fine.”
How to Use MB
Learner’s notesIn plain EnglishA unit for measuring file size, or in chat, a quick way of saying "my bad".
The storage sense is neutral and technical; the "my bad" sense is slang and belongs only in casual messages.
Leave a space between the number and the unit and keep the B capital for bytes: 250 MB, not 250mb.
Trace the full origin ↓Fill the Gap
Can you complete this real example?
The photo is about 4 _____, so it should attach fine.
Etymology
An initialism of megabyte, from the prefix mega- (Greek megas 'great') plus byte.
Synonyms
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Frequently Asked Questions
What is the difference between MB and Mb?
Capital B means bytes and lower-case b means bits, and there are eight bits in a byte. So 100 Mb per second of broadband delivers roughly 12.5 MB of files per second.
How many MB are in a GB?
1,024 MB in a gigabyte when counted in binary, or 1,000 MB under the decimal system that storage manufacturers and network operators use. That difference is why a drive sold as 500 GB shows up as slightly less on your computer.
What does mb mean in a text message?
In casual messaging, lower-case "mb" is usually short for "my bad", a quick way of admitting a small mistake. Context makes it clear, since nobody apologises in megabytes.
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