Type a value into any field and instantly see it converted across bytes, KB, MB, GB, TB and PB — switch between decimal and binary modes to match how your device reports storage.
Decimal mode matches how drive manufacturers and network speeds define KB/MB/GB (powers of 1000).
Runs entirely in your browser — nothing you enter is uploaded or stored.
Bytes, KB, MB, GB, TB and PB all update together as you type.
One toggle switches every field between 1000-based and 1024-based math.
No accounts, no uploads — every calculation stays on your device.
Pick the unit system that matches your source, then enter a value in whichever field you already have.
Data storage has two competing sets of prefixes because of a decades-old ambiguity. The SI decimal standard defines a kilobyte as exactly 1,000 bytes, a megabyte as 1,000,000 bytes, and so on, using clean powers of ten. Computers, however, address memory in powers of two, so operating systems and much older software instead treat "kilobyte" as 1,024 bytes, "megabyte" as 1,024² bytes, and so on — officially called kibibytes, mebibytes and gibibytes, though the KB/MB/GB labels are still used loosely for both.
This is why a drive advertised as 1 TB (1,000,000,000,000 bytes, decimal) shows up as roughly 931 GiB in a binary-mode file explorer, without any storage actually missing. This tool lets you pick the exact system you need and keeps every field consistent with that choice.
Drive capacity, network bandwidth and SSD marketing figures are defined in decimal (powers of 1,000).
Windows, macOS and most file managers report used and free space using binary math, though often still labeled KB/MB/GB.
1 GB (decimal) is 1,000,000,000 bytes. 1 GiB (binary) is 1,073,741,824 bytes — about 7.4% larger.
1 PB is 1,000 TB in decimal, or 1,024 TiB in binary — the scale used for large cloud storage and datacenter capacity.
Common questions about bytes, KB, MB, GB, TB and the decimal vs binary confusion.
Decimal units use powers of 1000 (1 KB = 1,000 bytes, defined by the SI and used by drive manufacturers), while binary units use powers of 1024 (1 KiB = 1,024 bytes, used internally by most operating systems). The same file can show a different size depending on which system is used.
Manufacturers advertise capacity in decimal terabytes (1 TB = 1,000,000,000,000 bytes), but operating systems usually report space in binary units labeled TB but calculated as 1,024^4 bytes. A 1 TB drive shows as about 931 GiB in Windows, even though no space is missing.
In decimal, 1 GB is exactly 1,000,000,000 bytes. In binary, 1 GiB is exactly 1,073,741,824 bytes (1,024 cubed). This tool labels the difference clearly and lets you switch between the two.
Use decimal for marketing specs, network transfer speeds and storage capacity listings. Use binary (1024-based) when comparing against what your operating system's file explorer reports for used or free space.
No. A kilobyte (KB) is formally 1,000 bytes under the SI-based decimal standard, while a kibibyte (KiB) is exactly 1,024 bytes under the binary standard. Many tools use "KB" loosely to mean either one.