How many megabytes are in a gigabyte?

Using the SI decimal standard: 1 GB = 1,000 MB. Using the IEC binary standard: 1 GiB (gibibyte) = 1,024 MiB (mebibytes). Storage manufacturers use GB; most operating systems use GiB but label them "GB."

Why does my 1 TB hard drive show less space in Windows?

The manufacturer rates the drive in SI gigabytes (powers of 1,000). Windows reports capacity in gibibytes (powers of 1,024) while calling them "GB." Since 1 GiB > 1 GB, the same byte count results in a smaller number when expressed in GiB.

What is the difference between MB and MiB?

MB (megabyte) follows the SI decimal system: 1 MB = 1,000 KB = 1,000,000 bytes. MiB (mebibyte) follows the IEC binary system: 1 MiB = 1,024 KiB = 1,048,576 bytes. 1 MiB is about 4.86% larger than 1 MB.

How do I convert megabytes to gigabytes?

Divide the megabyte value by 1,000 to get SI gigabytes (GB). Divide mebibytes by 1,024 to get binary gibibytes (GiB). For most practical purposes, dividing by 1,000 gives you the same number storage hardware advertises.

How accurate is this converter for very large values?

The converter uses JavaScript 64-bit floating-point (IEEE 754 double precision), which handles integers exactly up to 2^53 — about 9 quadrillion bytes. For any practical storage size in megabytes, the result is exact.

Megabytes to Gigabytes Converter

Enter a megabyte value and instantly get gigabytes (GB, decimal SI) and gibibytes (GiB, binary IEC), plus a quick-reference table.

Input — Megabytes

Number of megabytes

SI vs. binary: 1 GB (gigabyte, decimal) = 1,000 MB. 1 GiB (gibibyte, binary) = 1,024 MiB. Storage specs use GB; your OS reports GiB (but often labels them "GB").

Results

Enter a megabyte value and click Convert.

Reference Table — Common Megabyte Counts

Quick lookup for typical file and storage sizes.

Megabytes (MB)	GB (SI, ÷1,000)	GiB (binary, ÷1,024)	Typical example

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Summary

This tool converts a megabyte count into gigabytes using both the SI decimal standard (1 GB = 1,000 MB) and the IEC binary standard (1 GiB = 1,024 MiB). Storage manufacturers advertise capacity in SI units, while most operating systems report disk sizes in binary units — often labeling GiB as "GB." That mismatch explains why a "500 GB" drive shows less space in your OS. Use the reference table to look up common megabyte values at a glance.

How it works

Enter the number of megabytes in the input field.
The tool divides by 1,000 to get decimal gigabytes (GB, SI).
It also divides by 1,024 to get binary gibibytes (GiB, IEC), treating the input as mebibytes.
Results appear instantly with up to 10 significant digits.
Use the copy buttons to grab any result value.
Scroll down for a reference table of common megabyte counts in GB and GiB.

Use cases

Check how many GB a file size in megabytes occupies on a storage device.
Understand why a "500 GB" drive shows less space in your operating system.
Convert RAM or cache sizes from megabytes to gigabytes for reporting.
Translate download or upload sizes into human-readable gigabyte values.
Verify storage estimates when working with cloud storage pricing by the GB.
Cross-reference OS-reported sizes (GiB) against hardware specs (GB).

Frequently Asked Questions

Last updated: 2026-06-19 · Reviewed by Nham Vu