Data Storage Converter

Why your "1TB" drive shows less than 1TB

This calculator uses the traditional binary convention (each unit is 1024 times the previous one) common in operating systems - but storage device manufacturers typically advertise capacity using decimal units (each is 1000 times the previous one) instead, creating a well-known mismatch.

Worked example

For 1 GB:

Result = 1073741824.0 bytes = 1048576.0 KB = 1024.0 MB = 1.0 GB = 0.0009765625 TB

Frequently asked questions

Why does a "1 TB" hard drive show up as only about 931 GB? The manufacturer's "1 TB" uses decimal terabytes (1,000,000,000,000 bytes), while the operating system displays capacity in binary gibibytes labeled as GB (1,073,741,824 bytes each) - dividing the manufacturer's decimal terabyte by the OS's binary gigabyte gives approximately 931, explaining the apparent "missing" storage.

Is there a way to avoid this confusion? Some technical standards use "KiB," "MiB," "GiB," and "TiB" to explicitly denote binary units, reserving "KB," "MB," "GB," and "TB" for decimal units - but this convention isn't universally followed, so the ambiguity persists in most everyday software and marketing.