General tool / 07
File Size Converter
Convert between decimal bytes, KB, MB, GB and binary KiB, MiB, GiB.
File Size Converter: TOEA distinguishes decimal powers of 1,000 from binary powers of 1,024 and converts through bytes. Runs 100% locally in your browser with zero server file uploads.
- Category
- Everyday tools
- Runs
- In your browser
- Cost
- Free · no sign-up
- Availability
- Ready to use
Runs entirely in your browser
Why a new drive looks smaller
Drive makers count in decimal, so a 1 TB drive holds 1,000,000,000,000 bytes. Windows divides by powers of 1,024 but still writes GB, so the same drive shows as about 931 GB, and a 500 GB drive as about 466 GB. Nothing is missing; the two numbers use different units. macOS has reported sizes in decimal units since 2009, which is why the same file can show slightly different sizes on a Mac and a PC.
Bits, bytes, and attachments
Network speeds are quoted in bits per second and file sizes in bytes, with 8 bits to the byte. A 100 Mbps connection moves at most about 12.5 MB per second, so a 1 GB download takes at least 80 seconds before any overhead.
Email attachments are encoded as text on the way, which adds roughly a third to their size. Under a 25 MB limit, files totalling around 18 MB are a safer ceiling than 25.
How to use it
- Enter a size and unit.
- Calculate all equivalents.
- Copy the conversion table.
Privacy & limitations
The value stays local. This converts units; it does not resize a file.
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Frequently asked questions
Does this upload my input?
No. The work happens in your current browser tab.
What is the difference between MB and MiB?
One MB is 1,000,000 bytes; one MiB is 1,048,576 bytes.
Free tool · runs in your browser · no account required