Convert file sizes between Bytes, KB, MB, GB, TB, and PB.
File size conversion is the process of translating a digital storage measurement — like Megabytes or Gigabytes — into a different unit. It matters because storage sizes are used everywhere: checking how much space a download needs, comparing cloud storage plans, or understanding why a “500 GB” drive shows less space than expected.
Most confusion comes from two different counting systems. Storage manufacturers typically use the decimal system (1 KB = 1,000 bytes), while operating systems often use the binary system (1 KB = 1,024 bytes). This is exactly why a drive labeled 500 GB can show up as roughly 465 GB in your file explorer — both numbers are “correct,” just using different math.
Our File Size Converter calculates both binary and decimal results side by side, so you always know exactly what you’re looking at.
Convert file sizes instantly — no setup, no installation required.
Results update the moment you enter a value — no reload, no waiting.
See both 1024-based and 1000-based results side by side, so there's no confusion about which one applies.
Convert between Bytes, KB, MB, GB, and TB in any direction.
Precise calculations with no rounding errors, even for very large or very small values.
All conversion happens in your browser. Nothing you enter is stored or sent anywhere.
No account or subscription needed. Open the page and start converting immediately.
A file manager, a download page, and a storage manufacturer's spec sheet may each calculate sizes differently (binary vs. decimal), leading to numbers that don't quite match.
Internet speeds are usually measured in megabits (Mbps), while file sizes are measured in megabytes (MB). 1 byte = 8 bits, so mixing these up can make a download time estimate wildly wrong.
Converting in stages (e.g., MB → GB → TB) and rounding at each step can introduce small errors; convert directly between the two units you actually need.
A file's size on disk and the time it takes to transfer over a network are related but not the same calculation; this tool covers storage size, not transfer speed.