Spec sheets love to switch units mid-sentence. A drive is listed in TB, a download speed in Mbps, a file size in GB, and a streaming bitrate in MB/s — and a wrong conversion silently breaks your estimate. Mixing them up is how people "find" 100 GB of missing space or misjudge how long a transfer takes.
The Unit Converter handles the two pairs that cause the most confusion. Storage: 1 TB is 1000 GB in drive marketing but 1024 GB in some OS views, so know which you're using when you plan capacity. Data rate: Mbps (megabits per second) is one-eighth of MB/s (megabytes per second), so an "800 Mbps" connection moves roughly 100 MB/s at best — a factor-of-eight gap that wrecks download-time math if ignored.
Why it matters for a build: you size an SSD against your real library in consistent units, and you set expectations for game downloads and cloud backups against the true throughput. Consistent units turn a vague "should be enough" into a number you can defend.
Keep the converter open whenever you're comparing parts or estimating transfers. Convert first, compare second, and the spec sheet stops lying to you by unit.