What is mb

Last updated: April 1, 2026

Quick Answer: A megabyte (MB) is a digital storage unit equal to one million bytes, or approximately 1,000 kilobytes. It's used to measure file sizes like photos, documents, and small videos.

Key Facts

Definition of Megabyte

A megabyte (MB) is a unit of digital information used to measure data storage capacity and file sizes. The term combines "mega," meaning one million, with "byte," the basic unit of digital storage. One megabyte represents approximately one million bytes of data.

Decimal vs. Binary Megabytes

There are two slightly different definitions of a megabyte:

This difference explains why a file might show as "100 MB" when you buy it but appears slightly smaller when stored on your device. Most consumer devices and software use the decimal definition.

Common File Sizes

Understanding megabytes helps you gauge file sizes and storage needs. A typical smartphone photo is 2-5 MB, a high-quality document is 0.5-2 MB, an MP3 song is 3-5 MB, and a short video clip is 10-50 MB. Large video files, such as movies or 4K footage, are measured in gigabytes.

Storage Hierarchy

The megabyte fits within a larger system of digital storage units:

Practical Applications

Email providers limit attachment sizes (often 25-50 MB), cloud storage is measured in gigabytes and terabytes, and RAM specifications indicate how many megabytes or gigabytes your device has. Understanding megabytes helps you determine storage needs and manage device capacity effectively.

Related Questions

How many MB are in a GB?

1 gigabyte (GB) equals 1,000 MB (decimal) or 1,024 MB (binary). This conversion helps you understand storage capacity when comparing device specifications and cloud storage plans.

What is the difference between MB and Mbps?

MB measures file size and storage capacity, while Mbps measures internet speed. MB refers to megabytes (8 million bits), and Mbps refers to megabits per second. They measure different things entirely.

How much storage do I need for photos?

A typical smartphone photo is 2-5 MB. A 1,000-photo collection needs roughly 2-5 GB of storage. High-resolution or 4K photos require more space, while compressed formats need less.

Sources

  1. Wikipedia - Megabyte CC-BY-SA-4.0
  2. NIST - Binary Prefixes Public Domain