Electrical Fundamentals
Resistance Temperature Calculator
Resistance Temperature helps you find resistance at new temperature from reference resistance, temperature coefficient, and temperature change. The page keeps the arithmetic visible so you can check the result against the original measurements.
Calculate Resistance at new temperature
Use measurements from one operating condition.
Formula used on this page
This page evaluates R = R₀ × (1 + αΔT). The participating entries are Reference resistance, Temperature coefficient, and Temperature change.
Using the loaded examples gives 119.25 Ω. Your saved case should identify where each entry came from.
Calculate resistance at new temperature from reference resistance, temperature coefficient, and temperature change. Use Conductor Resistance Calculator as the companion source for conductor resistance.
Input notes
Use readings taken at the same circuit state and reference node. Do not combine a worst-case value with unrelated nominal data.
Confirm decimal placement whenever a source uses a different unit scale. Battery Heat Generation Calculator provides the related battery heat check.
- Reference resistance
- Default example: 100 Ω. Enter reference resistance in Ω.
- Temperature coefficient
- Default example: 0.00385 /°C. Enter temperature coefficient in /°C.
- Temperature change
- Default example: 50 °C. Enter temperature change in °C.
How to use the result
Interpret Resistance at new temperature on the same basis used for the source values. Compare it with the expected circuit operating point.
Keep the input set beside the output so another reader can reproduce it. Keep Current Divider Calculator available for the companion calculation.
Where this estimate can fail
The linear coefficient is an approximation over a limited temperature range.
The equation does not include lead and contact resistance, source impedance, and temperature drift. Test an additional scenario when an omitted effect has a plausible range.
Keep source conditions with each voltage, current, resistance, or charge value.
A second scenario
Change Reference resistance from 100 Ω to 120 Ω with the rest of the inputs held constant. The comparison runs from 119.25 Ω to 143.10 Ω.
The comparison demonstrates sensitivity, not a guaranteed field response.
Documenting the calculation
Document reference resistance, temperature coefficient, and temperature change with resistance at new temperature. Keep enough context to reproduce the result later.
Transfer resistance at new temperature as the raw numerical value until the final step. Apply standard sizes only after all checks are complete.
Questions about inputs and assumptions
Should I use measured or nameplate values?
Measured and rated values can represent different states. Record conductor temperature and whether values are measured, nominal, or calculated.
What is not captured by this equation?
The linear coefficient is an approximation over a limited temperature range. A broader review should include reference-node errors, heating, and nonideal source behavior.
Why might measured resistance at new temperature differ?
Differences can come from reference-node errors, heating, and nonideal source behavior, measurement uncertainty, or values taken under different conditions.