Data Storage Converter
Why is My 1 TB Hard Drive Only 931 GB?
Have you ever bought a new hard drive or USB stick, plugged it in, and noticed it has less storage space than advertised? You're not alone. This isn't a defect; it's due to a difference in how manufacturers and operating systems measure data.
• Manufacturers use Decimal (Base-10): They define 1 Kilobyte (KB) as 1,000 bytes, 1 Megabyte (MB) as 1,000 KB, and so on. It's clean, round math.
• Computers use Binary (Base-2): Operating systems like Windows measure data in powers of 2. For them, 1 Kibibyte (KiB) is 1,024 bytes. This is the true, technical definition.
When a manufacturer sells a "1 Terabyte (TB)" drive, they mean 1,000,000,000,000 bytes. But your computer divides that number by 1024x1024x1024 to show you the space in Gibibytes (GiB), which results in the smaller "931 GB" figure. Our converter includes both KB/MB/GB (decimal) and KiB/MiB/GiB (binary) units so you can see the difference for yourself.
Megabits vs. Megabytes: Internet Speed Explained
Another common point of confusion is internet speed. Internet Service Providers (ISPs) advertise speeds in Megabits per second (Mbps), but your web browser and download clients show speeds in Megabytes per second (MB/s).
- There are 8 bits in 1 byte.
- To convert your internet speed from Mbps to MB/s, simply divide by 8.
For example, a 100 Mbps internet connection will give you a maximum theoretical download speed of 12.5 MB/s (100 ÷ 8).
Unit Comparison Cheat Sheet
| Unit Name | Abbreviation | Equivalent in Bytes | Typical Use |
|---|---|---|---|
| Kilobyte | KB | 1,000 Bytes | Marketing, File Size (macOS) |
| Kibibyte | KiB | 1,024 Bytes | File Size (Windows), RAM |
| Megabyte | MB | 1,000,000 Bytes | Song file sizes, photos |
| Mebibyte | MiB | 1,048,576 Bytes | Precise technical measurement |
| Gigabyte | GB | 1,000,000,000 Bytes | Hard Drive capacity, Movie sizes |
| Gibibyte | GiB | 1,073,741,824 Bytes | How Windows reports drive capacity |