Digital storage

KB to MB Converter

Convert kilobytes and megabytes both ways. Toggle between binary (1024) and decimal (1000) factors.

How to convert KB to MB

To convert kilobytes (KB) to megabytes (MB), divide the number of kilobytes by the conversion factor. There are two widely used factors, and this converter supports both:

Binary (1024): 1 MB = 1024 KB. Used by Windows, RAM and most operating systems when they report file and memory sizes.
Decimal (1000): 1 MB = 1000 KB. Used by storage manufacturers, network speeds and the official SI definition.

So 5120 KB ÷ 1024 = 5 MB (binary), or 5120 KB ÷ 1000 = 5.12 MB (decimal). Type a value in either box above and the other updates instantly — it works both directions.

KB to MB conversion table (binary, ÷1024)

Kilobytes (KB)	Megabytes (MB)
256 KB	0.25 MB
512 KB	0.5 MB
1024 KB	1 MB
2048 KB	2 MB
5120 KB	5 MB
10240 KB	10 MB
102400 KB	100 MB

Binary vs decimal — which should I use?

If you are checking a file size shown by your computer, use binary (1024). If you are matching the capacity printed on a hard drive, USB stick or an internet plan, use decimal (1000). The difference grows with size: a "1 TB" drive shows as roughly 931 GB in Windows for exactly this reason.

Worked example: is a 4,700 KB photo too big to email?

Say your camera saved a photo at 4,700 KB and your email provider caps attachments at "25 MB". Using the binary factor, 4,700 ÷ 1024 = 4.59 MB, so a single photo is comfortably under the limit and you could attach several. Using the decimal factor a supplier might quote, 4,700 ÷ 1000 = 4.7 MB — a slightly larger number for the exact same file. The file never changed size; only the divisor did. When a limit and a file size come from different places, convert both with the same factor before comparing.

Where binary vs. decimal MB actually shows up

Your operating system: Windows File Explorer and macOS Finder can report slightly different sizes for the same file because one may divide by 1024 and the other by 1000.
Drive packaging: hard drive and SSD boxes almost always use the decimal (1000) standard, which is why a "1 TB" drive shows less than 1 TB of usable space in a binary-based operating system.
Network speed: internet plans are sold in megabits per second (Mbps), a different unit from megabytes (MB). Divide Mbps by 8 to estimate MB per second — a 100 Mbps line downloads at roughly 12.5 MB/s.

Common KB and MB sizes people look up

A few reference points make the scale easier to picture: a plain-text email is often just 10–20 KB, a high-quality photo runs 2,000–6,000 KB (2–6 MB), a three-minute MP3 is around 3,000–5,000 KB, and a minute of 1080p video can be 50,000 KB (about 50 MB) or more. Because operating systems group files in binary, a folder your computer labels "100 MB" actually holds 102,400 KB, not 100,000.

Bits, bytes, KB, MB and GB — the full ladder

All digital sizes climb the same ladder. Eight bits make one byte; 1,024 bytes make a kilobyte (KB); 1,024 KB make a megabyte (MB); 1,024 MB make a gigabyte (GB); and 1,024 GB make a terabyte (TB) — using the binary factor. Each step up multiplies by the same number, so the same ÷1024 (or ×1024) you use for KB and MB works at every level. To jump two rungs, apply the factor twice: 1 GB is 1,024 × 1,024 = 1,048,576 KB. Storage makers use 1,000 at each rung instead, which is the whole reason advertised and reported capacities disagree. In everyday terms, a plain document is a handful of KB, a phone photo is a few MB, a full-length movie download is a few GB, and a laptop's storage is measured in hundreds of GB or a small number of TB — the same ladder, just read at different rungs.

Frequently asked questions

How many KB are in 1 MB?

It depends on the factor. In binary (used by operating systems) 1 MB = 1024 KB. In decimal (used by storage makers and SI) 1 MB = 1000 KB.

Is 1024 KB equal to 1 MB?

Yes, under the binary convention that Windows and most operating systems use, 1024 KB = 1 MB. Under the decimal SI convention, 1000 KB = 1 MB.

How do I convert MB back to KB?

Multiply the megabytes by your factor: MB × 1024 (binary) or MB × 1000 (decimal). Just type into the Megabytes box above and the KB value fills in automatically.

Does this converter store my data?

No. Everything runs locally in your browser — your input isn't uploaded or stored.

Why does my hard drive show less space than advertised?

Manufacturers measure capacity with the decimal (1000) standard, but operating systems usually report space with the binary (1024) standard. The same drive therefore looks smaller in your OS — a "1 TB" drive shows as roughly 931 GB in Windows.

What is the difference between MB and Mbps?

MB (megabytes) measure file size or storage, while Mbps (megabits per second) measure network speed. There are 8 bits in a byte, so divide a Mbps figure by 8 to estimate megabytes per second.