You are installing an electric water heater in a garage.
Looking at the chart, 2.5 mm² cable is rated for roughly 20–25 Amps. It looks close, but the distance is 20 meters. how to calculate the cable size
But this approach misses the deeper, more interesting reality. Choosing a cable is not a simple lookup; it is an act of engineering compromise, a balancing act between physics, economics, and safety. The question "how to calculate the cable size" is actually four intertwined questions in a trench coat. You are installing an electric water heater in a garage