Data Storage Converter

How to Use the Data Storage Converter

Enter a data size, pick its unit and the unit to convert to, and the result appears instantly. This tool uses the binary convention (1 KB = 1024 bytes), which is how operating systems like Windows and macOS typically report file and drive sizes. Use the swap button to flip the from/to units in one click.

Worked Examples

• 1 gigabyte to megabytes: 1 GB = 1024 MB under the binary convention, the number your file manager uses when it reports a folder's size.
• 1 terabyte to gigabytes: 1 TB = 1024 GB, so a "2 TB" external drive holds roughly 2048 GB of addressable binary storage before formatting overhead.
• 1 byte to bits: 1 byte = 8 bits, the fixed relationship behind every byte-to-bit or bit-to-byte conversion on this page.
• A 4.7 GB DVD to megabytes: 4.7 GB = 4,812.8 MB, useful when comparing DVD capacity against a folder of ripped files reported in MB.
• 1 petabyte to terabytes: 1 PB = 1024 TB, illustrating just how large the jump from personal-computing scale (GB/TB) to data-center scale (PB) really is.

Binary vs Decimal: Why Storage Numbers Don't Always Match

There are two competing definitions of "kilobyte." The binary convention, used by this tool and by Windows/macOS file size displays, defines 1 KB as 1024 bytes (2 to the 10th power), because computers work in powers of two internally. The decimal (SI) convention defines 1 KB as exactly 1000 bytes, matching how every other metric prefix works (kilometer = 1000 meters). Hard drive and SSD manufacturers use the decimal convention when advertising capacity, since it produces a larger, more marketable number, while your operating system reports the same physical bytes using the binary convention. That's why a drive sold as "1 TB" shows up as about 931 GB once you plug it in, no bytes are missing, it's the same drive measured two different ways.

Common Mistakes When Converting Data Storage

The single most common mistake is confusing bits and bytes, especially with internet speeds. ISPs and router manufacturers advertise connection speed in megabits per second (Mbps, lowercase b), while downloaded file sizes are measured in megabytes (MB, uppercase B). An advertised "50 Mbps" connection downloads at roughly 6.25 MB per second, not 50, because 1 byte equals 8 bits. Always check whether a number uses lowercase "b" (bits) or uppercase "B" (bytes) before comparing it to a file size.

A second common error is assuming decimal and binary units are interchangeable at large scales. The gap between the two conventions grows with size, at the kilobyte level it's about 2.4%, but by the terabyte level it's grown to about 10%, which is a large enough discrepancy to matter when estimating whether files will fit on a drive.

A third mistake is forgetting that formatted drive capacity is always a little less than raw capacity, since the file system itself (NTFS, APFS, ext4, and so on) reserves some space for its own indexing and metadata structures. This tool converts raw byte counts accurately, but the usable free space Windows or macOS shows you will typically be a few percent lower still, on top of the decimal-vs-binary gap already described above.

Real-World Use Cases

Storage shopping: figuring out how much usable space a "500 GB" or "2 TB" drive will actually show once formatted and reported by your operating system.

Cloud storage and backups: converting between GB and TB when comparing cloud storage plan tiers or estimating how many photos, videos, or documents will fit in a given plan.

Software and app development: converting file, memory, or bandwidth figures between bits, bytes, KB, and MB when working with APIs, memory limits, or network payload sizes.

Media and downloads: estimating download time or storage needs for video, music, or software given a file size in one unit and available space in another.

Frequently Asked Questions

Is 1 KB equal to 1000 bytes or 1024 bytes?

This tool uses 1024 bytes per kilobyte (the binary convention used by most operating systems for file sizes), rather than the strict SI-decimal 1000 bytes sometimes used for network speeds or drive marketing.

How many GB are in 1 TB?

1 terabyte equals 1024 gigabytes under the binary convention this tool uses, which matches how Windows File Explorer and most desktop operating systems display storage sizes.

Why does my new hard drive show less storage than advertised?

Drive manufacturers advertise capacity using the decimal convention (1 TB = 1,000,000,000,000 bytes), while your operating system reports it using the binary convention (1 TB = 1,099,511,627,776 bytes) but still labels it "TB" or "GB". A drive advertised as 1 TB will show up as roughly 931 GB in Windows or macOS, that's not missing storage, it's the same number of bytes measured under two different definitions of the unit.

What's the difference between a bit and a byte, and why does it matter for internet speed?

A byte is 8 bits. Internet and network speeds are conventionally advertised in bits per second (Mbps), while file sizes and downloads are measured in bytes (MB). A "100 Mbps" internet connection transfers about 12.5 megabytes per second, not 100, since you divide by 8 to go from bits to bytes. This mismatch is the most common source of confusion when estimating download times from an advertised speed.

How large is a typical DVD, photo, or song in gigabytes or megabytes?

A standard single-layer DVD holds 4.7 GB, which equals about 4,812.8 MB under the binary convention this tool uses. A typical smartphone photo is usually 3 to 8 MB, and an MP3 song at standard quality is usually 3 to 5 MB, so a 4.7 GB DVD's worth of storage could hold roughly 1,000 to 1,500 average-quality songs.

What comes after petabytes?

After petabyte (PB) comes exabyte (EB), zettabyte (ZB), and yottabyte (YB), each 1024 times larger than the last under the binary convention. These units are mostly relevant to large data centers and global internet traffic statistics rather than personal computing, which is why this tool stops at petabytes, already far beyond what any consumer device stores.