The Billion-Dollar Story: Even Pros Slip
In 1999 NASA lost its $125 million Mars Climate Orbiter because one team used imperial units while another used metric. One simple conversion via a trusted tool would have saved the mission. Human conversion errors aren't just a student problem — they happen in top laboratories.
Everyday Conversions You Actually Need
Length: an inch is exactly 2.54 cm (official definition). Weight: a pound ≈ 453.59 grams. Data: for computing a gigabyte = 1024 MB, but manufacturers use 1000 — that's why your drive shows less than labeled. These and more precise factors are ready in our [free unit converter](/en/tools/unit-converter).
Golden Rules That Prevent 90% of Errors
First: always write the unit next to every number — a number without a unit is meaningless. Second: roughly estimate before precise calculation (is the result plausible?). Third: never convert twice in sequence — go directly from source to target. Fourth: when in doubt, use a tool, not memory.