Byte Size Converter

Convert between bytes, KB, MB, GB, and their binary (KiB/MiB) forms.

This tool runs entirely in your browser. Your data is never uploaded, never stored, and never leaves your device.

One kilobyte is 1,000 bytes and one kibibyte is 1,024, and this puts both families in a single table so a size given in one is never silently read as the other.

How to use it

1Enter the number and pick the unit it is currently in — the kilobyte pair spells out the difference — "Kilobytes (KB, 1000)" against "Kibibytes (KiB, 1024)" — and the same 1000-versus-1024 split runs through the mega, giga and tera rows.
2Read the table below, which restates that size in every unit.
3Use the Copy button on any single row to take just that figure.

Example

Input: 1 · MB
Output: 1,000,000 B · 1,000 KB · 976.5625 KiB · 0.9536743164 MiB

A megabyte here is a flat 1,000,000 bytes, while a mebibyte is 1,048,576 — which is the whole reason a drive sold as 1 TB shows up as 931.3225746 GiB in an operating system that counts in binary units. The displayed figures are rounded to ten significant figures, but the row's Copy button hands over the full unrounded number, so the value you paste can be longer than the one you read. Sizes past 1e15, or below one millionth of a unit, switch to exponential notation.

What happens to your data

No file is involved at any point — you type a number, and all nine rows come from multiplying it by one constant and dividing by another, so nothing is opened, read or measured on your disk. Copying goes through navigator.clipboard.writeText and simply does nothing visible if the browser denies clipboard permission.

Last updated August 2026

Two figures can both be called a gigabyte and differ by 73,741,824 bytes. That gap is why a drive sold as 500 GB shows up as 465 the moment an operating system counts it, why a file size that looked safely under a 25 MB limit is refused anyway, and why a quota written in one document never quite matches the usage reported in another.

This puts one size in all nine units at once — bytes, KB, MB, GB and TB alongside the 1,024-based KiB, MiB, GiB and TiB — so both readings sit side by side and you can tell which one was meant. Type the number, choose the unit it is currently written in, and every row re-computes on each keystroke: there is no convert button to press and no file to upload.\n\nMost of what people need from a file size converter is one hop: MB to GB when a folder listing and a quota disagree, GB to MB when a limit is quoted in the smaller unit, MB to KB for an upload form that thinks in kilobytes, bytes to MB when something has reported a raw count. This data storage converter does every pairing at once, which matters because the trap is not the arithmetic \u2014 it is which of the two definitions of a megabyte the other side is using.

How it works

Toolvore keeps nine constants — 1, 1,000, 1,000,000, 1,000,000,000 and 1,000,000,000,000 for the decimal family, and 1,024 through 1,024⁴ for the binary one — and does the whole job with two operations: your figure is multiplied by the constant for the unit you picked to produce a single byte count, and that byte count is divided by all nine constants to fill the table. There is nothing to upload because there is nothing to choose: no file is opened, no request is made, and the number you typed lives in the page's state until you close the tab. What appears on screen is rounded to ten significant figures, grouped with commas and capped at ten decimal places, while each row's Copy button hands over the unrounded value the arithmetic actually produced. Anything at or above 1e15, or below a millionth of a unit, prints in exponential notation instead. The input is read as a plain number, so 1e6 is accepted, but a grouped figure pasted straight out of a file manager — 1,048,576 — is not: it clears the table and shows "Enter a non-negative number." until you strip the commas.

Common use cases

Checking a raw byte count from ls -l or a file properties dialog against an upload limit written in MB
Working out why a drive sold as 500 GB shows up as 465 once an operating system counts in binary units
Converting a block, cache or memory size quoted in MiB into the MB a spec sheet or invoice uses
Seeing that a 25 MB export is 23.84185791 MiB, so a limit counted in 1,024s has room to spare
Reconciling a storage quota billed in gigabytes against usage a dashboard reports in gibibytes

Frequently asked questions

How do I convert KB to MB?＋

Divide by 1,000: there are 1,000 kilobytes in a megabyte, so 500 KB is 0.5 MB and 1 KB is 0.001 MB. That holds for the decimal units this tool labels KB and MB. The same 500,000 bytes read on the 1,024 scale are 488.28125 KiB, or 0.4768371582 MiB — the KiB and MiB rows are there so you can take a figure either way without doing the sum twice.

What is a kibibyte, and why not just say kilobyte?＋

A kibibyte is 1,024 bytes; the kilobyte here is a flat 1,000. The binary names — kibibytes, mebibytes, gibibytes and tebibytes — exist because "kilobyte" was used for both meanings for decades, and the discrepancy compounds as the units grow: 2.4% at the kilo step, 4.9% at mega, 7.4% at giga and 9.95% at tera. Enter 1 MiB and the byte row reads 1,048,576; 1 GiB reads 1,073,741,824.

Why does my 500 GB drive show up as 465?＋

Because it was sold in decimal gigabytes and the operating system is counting in binary ones while still writing "GB" on the label. Enter 500, choose Gigabytes (GB), and the GiB row reads 465.6612873 — the same 500,000,000,000 bytes, described on the other scale. Nothing has gone missing, though formatting does claim a little real space on top of that.

An upload limit says 25 MB — is that 25,000,000 bytes or 26,214,400?＋

It is rarely stated, and the safe assumption is the smaller one, since a file under 25,000,000 bytes clears both readings. Enter 25 and pick MB to see the gap: that is 23.84185791 MiB. Software is inconsistent about this even within one site — the image compressor here asks for its target in KB and treats each one as 1,024 bytes, so a 100 KB target returns a file of 102,400 bytes or less.

Why does 1 TiB show 1,099,511,628,000 bytes when a tebibyte is 1,099,511,627,776?＋

The displayed number is rounded to ten significant figures and a tebibyte needs thirteen, so the last three digits are lost on screen. The Copy button on that row is not rounded — it gives 1099511627776 exactly. A second cap trims the other end, where the display stops at ten decimal places: 1 KB reads 0.0009536743 MiB while the copied value is 0.00095367431640625. When the exact byte count matters, copy the row rather than reading it off.

Can it handle megabits, or petabytes?＋

Neither, and both are worth knowing before you arrive. All nine rows are bytes, so there is nothing here for the bit-based figures that broadband speeds and video bitrates use — a 100 Mb/s line is 12.5 MB/s and you will have to divide by eight yourself. The scale also stops at tera, so a petabyte has to go in as 1,000 TB and a pebibyte as 1,024 TiB; at 1e15 and above the display switches to exponential notation, so 5,000 TB reads 5.0000e+15 in the byte row. The sums also run in ordinary JavaScript numbers, which count whole bytes exactly only to 9,007,199,254,740,991 — about 9 PB — so a copied figure past that can be a byte or two out.