Type a number of bytes and read the result in kilobytes straight away. A kilobyte is 1,024 bytes in the binary system, so the converter divides your value by 1,024. Use Swap order to convert kilobytes to bytes instead.

A byte is the basic unit of data size, and a kilobyte is 1,024 bytes. Raw sizes in bytes show up in file properties, in the output of system commands and in API responses — converting them to kilobytes makes them easier to read and compare.
The relationship is fixed: 1 KB is 1,024 B in the binary system, which operating systems and this converter use. To turn bytes into kilobytes, divide their number by 1,024. The converter does this the moment you type a value.
Watch out for two systems. In the decimal system (SI), 1 KB is 1,000 B — that is how storage makers count, for example. This converter uses the binary system (1,024 B), matching what Windows and macOS show. Do not mix bytes up with bits either: 1 byte is 8 bits.
The conversion rests on a fixed relationship: one kilobyte is 1,024 bytes. To turn bytes into kilobytes, divide their number by 1,024.
Full formula: kilobytes = bytes ÷ 1,024. The other way: bytes = kilobytes × 1,024.
Example: a file is 51,200 bytes. Calculation: 51,200 ÷ 1,024 = 50 KB. The multiplier 1,024 comes from the fact that computers count in binary, and two to the power of ten is exactly 1,024.
Why 1,024 and not 1,000? In the decimal system (SI), 1 KB is 1,000 B, and that is how storage makers state capacity. Operating systems and this converter use the binary system, where 1 KB is 1,024 B — formally called a kibibyte (KiB).
The table below converts common byte values into kilobytes in the binary system (÷1,024). To convert another value, use the converter above.
| Bytes | Kilobytes |
|---|---|
| 512 B | 0.5 KB |
| 1,024 B | 1 KB |
| 2,048 B | 2 KB |
| 5,120 B | 5 KB |
| Bytes | Kilobytes |
|---|---|
| 10,240 B | 10 KB |
| 20,480 B | 20 KB |
| 51,200 B | 50 KB |
| 102,400 B | 100 KB |
| Bytes | Kilobytes |
|---|---|
| 256,000 B | 250 KB |
| 512,000 B | 500 KB |
| 1,048,576 B | 1,024 KB |
Example: 1,024 B ÷ 1,024 = 1 KB. Want to convert kilobytes to bytes? Click Swap order in the converter above.
Sizes in bytes come up mostly in technical contexts.
1 kilobyte is 1,024 bytes in the binary system, which this converter and operating systems use. In the decimal system (SI), used by storage makers among others, 1 KB is 1,000 bytes.
1,024 bytes is exactly 1 KB. Calculation: 1,024 ÷ 1,024 = 1 KB. This is the base relationship between the byte and the kilobyte, which is why it is looked up most often.
Divide the number of bytes by 1,024. For example, 51,200 B ÷ 1,024 = 50 KB. The converter does this the moment you type a value, with no button to click.
Multiply the number of kilobytes by 1,024. For example, 10 KB × 1,024 = 10,240 B. Click Swap order to have the converter work in this direction.
It depends on the system. Operating systems and this converter use the binary system, where 1 KB is 1,024 B. Storage makers use the decimal system, where 1 KB is 1,000 B. That is why the same number of bytes can give a slightly different result in KB.
KiB (kibibyte, the IEC standard) is always exactly 1,024 B. KB in the SI system is 1,000 B. In everyday use most people write KB while meaning 1,024 B, which is technically KiB. This converter uses 1,024 B.
1 byte is 8 bits. Mind the notation: KB means kilobytes (file size), while Kb means kilobits (often transfer speed). This tool works with bytes and kilobytes, not bits.

If you have spotted an error in the table or have an idea to improve the converter, write to us. We reply to every message.