Drive manufacturers label capacity using decimal terabytes (1TB = 1,000,000,000,000 bytes), but your operating system displays that same byte count using binary units labeled “GB,” where 1 GB actually means 1,073,741,824 bytes. Doing the math, 1 trillion bytes divided by that binary GB size comes out to about 931 GB, which is exactly the “missing” space people notice, nothing is actually lost, it’s purely a labeling and counting convention difference.

Both are technically correct, they’re just different, deliberately defined standards for different contexts. The International Electrotechnical Commission (IEC) created the KiB/MiB/GiB naming specifically to remove ambiguity, with “KB” technically meaning 1000 bytes under SI decimal rules and “KiB” unambiguously meaning 1024 bytes. In casual conversation, most people still say “GB” when they mean either one, which is where the confusion originates.

RAM capacity is always manufactured and reported in binary units (powers of 1024), unlike storage drives, which is why a stick of “16GB” RAM is actually exactly 17,179,869,184 bytes with no discrepancy or “missing” memory. This is because memory addressing in hardware is inherently based on powers of 2, unlike drive capacity marketing which historically adopted decimal for larger, rounder looking numbers.

Most major cloud storage providers report your used and available space using decimal (1000 based) units, matching the same convention drive manufacturers use, so a listed “15 GB free” plan means 15,000,000,000 bytes. This is generally consistent across most cloud services today, though it’s always worth checking a specific provider’s documentation if the exact figure matters for your use case.

A byte is 8 bits, and it’s the fundamental unit storage is measured in, while bits are typically used for measuring data transfer speed instead (see our dedicated data transfer speed converter for that conversion). This tool works exclusively in bytes and its multiples, since that’s the standard unit for file sizes and storage capacity.

After petabyte comes exabyte (EB), then zettabyte (ZB), then yottabyte (YB), each 1000 (or 1024 in binary) times larger than the last. These units are mostly relevant to data center and global internet infrastructure scale discussions rather than everyday personal computing, which is why this tool focuses on the more commonly needed units up through petabyte.

This usually comes down to the same decimal vs binary convention difference, some tools and operating systems label binary units (1024 based) as “MB” or “GB” when they technically mean MiB or GiB, while others correctly use decimal. Comparing the raw byte count, which stays constant regardless of labeling, is always the most reliable way to check if two reported sizes actually match.

No, all calculations happen locally in your browser, nothing is sent to a server or stored.