An API returns a file size of 4,200,000 bytes. How many MB is that?

4.2 MB. Divide 4,200,000 by 1,000,000.

A file is 1,048,576 bytes. Is that 1 MB?

Not in decimal units. 1,048,576 B is 1.048576 MB. It is exactly 1 MiB, the binary unit.

An upload limit says 10 MB. How many bytes can I send?

10,000,000 B if the limit uses decimal MB. If the service means MiB, the limit is 10,485,760 B. Check the service's documentation for which one it uses.

How many bytes are in 1 MB?

1,000,000 B. This converter uses decimal units.

Bytes (B) to Megabytes (MB) Converter

Enter a value to instantly convert between data storage units.

From

Precision4 dp

1 Byte = 0 Megabyte

Key Formulas

Megabyte → Gigabyte

GB = MB × 0.001

Gigabyte → Megabyte

MB = GB × 1000

Gigabyte → Terabyte

TB = GB × 0.001

Terabyte → Gigabyte

GB = TB × 1000

Formula

MB = B ÷ 1,000,000

An API response or log line may give a size in bytes, while upload limits and storage plans use megabytes. Divide the byte count by 1,000,000 to get megabytes. This converter uses decimal units, where 1 MB is 1,000,000 B. A binary MiB is 1,048,576 B, so the same byte count comes to fewer MiB than MB. See the MB vs MiB guide and KB to MB.

Source: NIST: decimal prefixes and explicit binary prefixes; 1 byte = 8 bits

Reviewed by the Convert Calc editorial team · Last reviewed: 2026-10-22 · see our methodology

Frequently Asked Questions

Real-World Examples

Example: a config file of 1,000 B.

1000 B = 0.001 MB

Example: a JSON response of 500,000 B.

500000 B = 0.5 MB

Example: an image upload of 2,500,000 B.

2500000 B = 2.5 MB

Example: a log file of 15,000,000 B.

15000000 B = 15 MB

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