Data Storage Converter
Convert between bits, bytes, KB, MB, GB and TB, using the binary (1,024-based) units your operating system uses.
What this calculator does
Digital storage is measured in units that scale by powers of 1,024 (binary) in most operating systems, though the same unit names are sometimes used with powers of 1,000 (decimal) by hardware manufacturers — a well-known source of confusion when a "1 TB" hard drive shows up as roughly 931 GB in your file explorer. This calculator uses the binary convention (1 KB = 1,024 bytes), matching what Windows, macOS and most software display.
The conversion factors used
- 1 byte = 8 bits
- 1 KB = 1,024 bytes
- 1 MB = 1,024 KB = 1,048,576 bytes
- 1 GB = 1,024 MB
- 1 TB = 1,024 GB
Worked example
1 GB converted to MB: 1 × 1,024 = 1,024 MB. This is the number your operating system shows when it reports free disk space or file sizes — it's why a "1 GB" file actually shows as 1,024 MB (not 1,000 MB) in most file managers.
Why hard drives show less space than advertised
Storage manufacturers typically advertise capacity using decimal units (1 TB = 1,000,000,000,000 bytes), while operating systems report it using binary units (1 TB ≈ 1,099,511,627,776 bytes). The same physical drive, measured both ways, shows a smaller number in binary GB/TB than in decimal — this isn't missing storage, it's two different definitions of the same unit name.
When this matters
Useful for estimating how many photos or videos fit on a device, sizing a cloud storage or backup plan, understanding a download size relative to your data plan, or converting a file size mentioned in one unit to compare against another.
Frequently asked questions
This calculator uses binary units (powers of 1,024), which is the convention operating systems like Windows and macOS use to report file sizes and storage. Some manufacturers instead advertise storage capacity using decimal units (powers of 1,000), which is why a drive's "true" size can look smaller once formatted.
Because the manufacturer's advertised capacity uses decimal (1,000-based) units, while your operating system reports free space in binary (1,024-based) units. The physical storage is the same — it's a difference in how the same unit name is defined.
A bit is a single binary digit (0 or 1). A byte is a group of 8 bits, and is the basic unit most file sizes are measured in.
Not directly — internet speeds are typically measured in bits per second (Mbps), while file sizes are measured in bytes. Remember to divide by 8 when comparing a download speed in Mbps to a file size in MB.