Decimal (1000) vs. binary (1024)
This is the most common confusion about storage: HDD/SSD manufacturers use the decimal standard (1 GB = 1,000,000,000 bytes), while Windows and most operating systems display size in binary (1 GiB = 1,073,741,824 bytes, though they usually mislabel it "GB" in the interface) — that's why a "500 GB" SSD shows up as "465 GB" in Windows: it's the same number of bytes, just measured with the binary ruler (which "fits" less per unit).
How to use it
Choose the source unit and enter the value — the calculator shows the conversion to every other unit (decimal and binary) at once.
Frequently asked questions
Why is 1 KB sometimes 1000 bytes and sometimes 1024?
Technically, KB (kilobyte) should always mean 1000 bytes (SI decimal standard), and KiB (kibibyte) should always mean 1024 — but for decades, software (mainly Windows) used "KB" to mean 1024, creating the confusion. This calculator follows the technically correct definition: KB=1000, KiB=1024.
Which one do I use to calculate internet speed?
Internet speed is always advertised in bits per second, in the decimal standard (e.g. a "100 Meg" plan is 100 Mbps = 100,000,000 bits/s) — divide by 8 to get the actual download speed in MB/s (bytes).