💾 Storage Space Calculator

Pick the size of the drive or card and the kind of file. The tool shows how many fit, and what the drive will show as its size in Windows.

Drive size

Unit

File type

Size of one file (MB)

Keep free (%)Drives slow down when completely full.

Files that fit

What Windows will show as the size

Why a 1 TB drive shows 931 GB

Drive makers count in thousands: 1 TB is 1,000,000,000,000 bytes. Windows counts in powers of 1,024, so the same bytes are shown as about 931 "GB". No space is missing; it is two ways of counting. Some space also goes to the file system and, on a phone, to the operating system.

Where the example sizes come from

The video and music sizes are worked out from their bitrate (data per second): one minute at 8 Mbps is 60 MB. Photo sizes vary a lot with the camera and format, so check one of your own files and type its size in.

For your own video settings, use the Video File Size Calculator.

Other tools you might need next

✂️ Split a File Break a large file into numbered pieces small enough to email or upload — and joinable again without any tool. 🧩 Join Split Files Reassemble .001 and .part pieces into the original file, with the order detected and missing pieces flagged. 🎲 Random File Generator Generate a dummy file of an exact size, random bytes or zeros, for testing upload limits and storage. 💰 Organic Traffic Value Calculator Put a price on your Google traffic: what the same clicks would cost as ads over 1, 3 and 5 years.

See all Developer Tools tools, or browse every free tool on the site.