Unit converter
Convert data size, throughput, and latency, and estimate how long a transfer takes.
Runs locally in your browser. Nothing is uploaded.
Data size
Decimal prefixes and binary prefixes are different units, and mixing them is how a “1 TB” disk looks smaller in an operating system that reports tebibytes. In this converter a kilobyte (kB) is 1000 bytes, a megabyte is 1000 squared, and so on. A kibibyte (KiB) is 1024 bytes, a mebibyte is 1024 squared, and a gibibyte is 1024 cubed. The labels on the menu spell that out so the unit you pick is the unit you meant. Bits are there too: a byte is eight bits. Networking people quote megabits per second, and file sizes are usually bytes, so the factor of eight is the whole argument.
The percentage calculator is the companion when you want “this file is what percent of the disk?” after you have both numbers in the same unit. Convert first, then take the ratio. Doing the ratio on mixed MB and MiB values is how the percent comes out slightly wrong.
Throughput, latency, and transfer time
Throughput units convert to bits per second. Mbit/s uses decimal millions of bits. MB/s on this page means a million bytes per second, and MiB/s means 1024 squared bytes per second. A link advertised as 100 Mbit/s moves 12.5 MB of payload per second only in the ideal case where every bit is payload. Real transfers spend some of the link on protocol overhead, so treat the transfer estimate as a ceiling, not a benchmark.
The transfer section asks for a size and a rate and returns a duration. Pick the size unit and the rate unit independently. Latency units run from nanoseconds to hours. They are a straight conversion: a millisecond is a thousandth of a second. They do not model a network. A round trip is something you measure. The converter only keeps the units honest when you write the number down.
The time zone converter answers a different “time” question: what clock reads the same instant somewhere else. Latency and transfer duration are lengths of time, not clock times, so they live here.
Common questions
Is 1 KB 1000 or 1024?
On this page, kB is 1000 and KiB is 1024. Marketing copy and some operating systems still say KB for 1024. When the distinction matters, use the explicit unit. When someone says “about a meg” for a casual file size, the 2.4% gap between MB and MiB is rarely the real problem.
Why is my download slower than the estimate?
The estimate is size times eight, divided by the bit rate you typed. It ignores TCP, TLS, packet headers, disk speed, and a rate limit. It answers the unit question. It does not speed-test your connection.
Can I convert miles or Celsius?
No. The converter is the set of units that show up next to system design: bytes, bit rates, and latencies. Everyday unit conversion is a different product, and a search box already answers most of those queries.
Are the numbers uploaded?
No. Multiplication and division run in the browser. A file size is rarely sensitive, and it still stays on the device.