Loading...
Convert between bytes, KB, MB, GB, TB and binary units
File size is the amount of digital storage space a file occupies, measured in bytes and its multiples. Decimal (SI) units use base 1000, while binary (IEC) units use base 1024.
Base 1000 - Used in storage marketing
1,000,000,0001,000,0001,000101.00e-6Base 1024 - Used in computing
1,000,000,000976,562.5953.670.939.09e-48.88e-7Decimal (SI) units use base 1000. Each step up multiplies by 1,000. This is how storage manufacturers advertise capacity.
Binary (IEC) units use base 1024. Each step up multiplies by 1,024. This is how computers actually calculate storage.
The ~2.4% difference per step compounds: a 1 TB drive shows as ~931 GiB in your OS.
Formula
Binary: 1 KiB = 1024 bytes | Decimal: 1 kB = 1000 bytesKiB, MiB, GiB, TiB = the IEC binary prefixes, each step a factor of 1024, used by Windows and by RAM
kB, MB, GB, TB = the SI decimal prefixes, each step a factor of 1000, used by drive makers, networks and macOS
bit vs byte = a byte is 8 bits, so a 100 Mbps line moves at most 12.5 MB per second
Worked Example
Why a 1 TB drive shows as 931 GB
Did you know? The gap compounds at every prefix step, a binary unit is 2.4% larger than its decimal namesake at kilobytes, 7.4% at gigabytes and 10.0% at terabytes. macOS switched to decimal units in 10.6, which is why the same drive reads 1 TB on a Mac and 931 GB on a PC.
Sources
Convert text to ASCII codes and back. Supports decimal, hex, binary, and octal formats.
Calculate required internet bandwidth based on devices and activities in your household.
Encode and decode Base64 strings. Convert text for data URIs, APIs, and safe data transmission.
Create CSS border-radius with visual controls for each corner. Generate circles, pills, and custom shapes.
Create CSS box shadows with multiple layers, live preview, and copy-ready code.
Preview how colors appear with different types of color blindness. Test accessibility for color vision deficiency.