An upload form only accepts a file size in KB, but my file manager shows 7 MB. What do I enter?

7 × 1,024 = 7,168 KB. Enter 7168.

Why is my 100 MB download showing as 102,400 KB instead of 100,000 KB?

Your OS uses the binary convention: 1 MB = 1,024 KB. 100 × 1,024 = 102,400. Decimal marketing math (100,000 KB) doesn't match what your file system actually reports.

How do I estimate MB to KB mentally?

Multiply by 1,000 for a rough number, then add about 2.4% for precision. Example: 20 MB × 1,000 = 20,000 (rough); the actual value is 20,480 KB.

My script needs a byte-size limit in KB, and the config docs specify a 2.5 MB max payload. What KB value do I hardcode?

2.5 × 1,024 = 2,560 KB. Hardcode 2560 as the limit.

Megabytes (MB) to Kilobytes (KB) Converter

Enter a value to instantly convert between data storage units.

From

Precision4 dp

1 Megabyte = 1024 Kilobyte

Key Formulas

Megabyte → Gigabyte

GB = MB × 0.000976563

Gigabyte → Megabyte

MB = GB × 1024

Gigabyte → Terabyte

TB = GB × 0.000976563

Terabyte → Gigabyte

GB = TB × 1024

Formula

KB = MB × 1024

Uploading to an API or filling out a form that reports sizes in KB, while you're thinking in MB? Multiply by 1,024 to match what the operating system or server actually expects — that's the binary convention nearly every file system uses.

Source: JEDEC Standard 100B.01 (traditional binary convention: 1 KB = 1024 B)

Reviewed by the Convert Calc editorial team · Last reviewed: 2026-08-11 · see our methodology

Frequently Asked Questions

Real-World Examples

A 1 MB image file — exactly 1,024 KB when reported by a file manager.

1 MB = 1024 KB

A 5 MB podcast episode — 5,120 KB in a directory listing.

5 MB = 5120 KB

A 10 MB PDF report — 10,240 KB, useful when a form's file-size field only accepts KB.

10 MB = 10240 KB

A 100 MB installer — 102,400 KB, the number a `du -k` command would show on Linux.

100 MB = 102400 KB

mb to gb gb to mb gb to tb tb to gb kb to mb

See This in Context

Developer Tools Data Storage