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Resistor Dissipation and Rating Calculator

Calculate actual resistor heating and compare derated continuous power and working-voltage limits; keep waveform and temperature conditions explicit.

Use this result well

Inputs that matter
Part and derating conditions, Resistance (ohm), DC or true RMS voltage (V), Maximum applied voltage magnitude (V), and 3 more
Output to expect
Resistor dissipation and actual ratings
  • Check the units and required inputs before comparing results.
  • Keep the assumptions with a copied result so you can reproduce the calculation later.
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Reference & details

How it works

Resistor dissipation and actual ratings

Calculate DC or true RMS resistor heating, then compare the actual derated continuous power and working-voltage limits. Specify crest voltage separately for an AC waveform. This steady-state check does not qualify pulses or surges.

P = Vrms² / R; Irms = Vrms / R. Compare P with allowable W and the maximum applied voltage magnitude with the documented working-voltage limit.

Updated: September 2026

Example Scenarios

Try this example to see the calculation, then enter actual documented values and preserve the measurement conditions. A failed or unresolved comparison is part of the record.

→ 1 W dissipated

FAQ

Calculate DC or true RMS resistor heating, then compare the actual derated continuous power and working-voltage limits. Specify crest voltage separately for an AC waveform. This steady-state check does not qualify pulses or surges.

Use the exact equipment data, measurement point, operating conditions and units described in the selected mode. Record source documents, dates and unresolved conditions in Sources and assumptions. Built-in examples illustrate arithmetic; they are not manufacturer ratings or approved designs.

Use Save planning case for an explicit local history entry. Copy MD keeps current inputs and notes; Download CSV exports the result breakdown. Export portable copies before clearing storage and save a separate case after changing equipment, conditions or measurements.

About Resistor Dissipation and Rating Calculator

Calculate DC or true RMS resistor heating, then compare the actual derated continuous power and working-voltage limits. Specify crest voltage separately for an AC waveform. This steady-state check does not qualify pulses or surges.