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METHODOLOGY

How the Extension cord load checker works

The ranking is rules, not opinion — here is exactly how an answer set becomes a ranked result and a safe next check.

source-governed Diagnostic estimate. Not a quote, not a substitute for a licensed electrician. sources verified 2026-06-20 view sources ↓

Method

  1. Voltage drop is computed exactly as a round-trip 2 × length × current × resistance-per-foot, then expressed as a percent of 120 V; the numbers and the rule appear in the trace.
  2. Two independent checks run: the load against a conservative per-gauge current ceiling (a fire question) and the voltage drop against 3% / 5% targets (a heat-and-performance question). The worse of the two sets the verdict.
  3. Recommendations err toward a heavier cord — the safe direction — and current in amps is simply the appliance's watts divided by 120 on a standard circuit.

Sources

Where to stop. Choosing or replacing an extension cord is homeowner-safe. Manufacturers and fire authorities advise plugging high-draw heating appliances such as space heaters directly into a wall receptacle rather than any extension cord. Anything involving the building's wiring or circuit rating is a licensed electrician's job. This is general information, not a quote and not a substitute for a licensed electrician.