How it works
Use uniform conductor resistivity with the units stated beside the fields. This form solves for length; enter the known quantities in Resistance, Resistivity, Area.
Inputs and units
| Input | Example value | What to enter |
|---|---|---|
| Resistance | 4.5 Ω | Formula symbol: R. Required unit: Ω. Must be greater than zero. |
| Resistivity | 0.0000015 Ω·m | Formula symbol: ρₑ. Required unit: Ω·m. Must be greater than zero. |
| Area | 0.00000075 m² | Formula symbol: A. Required unit: m². Must be greater than zero. |
Worked example
Show example inputs and results
This example is generated by the same calculation engine using the starting values in the form. Your own inputs produce your own result.
- Resistance
- 4.5 Ω
- Resistivity
- 0.0000015 Ω·m
- Area
- 0.00000075 m²
Complete example results
- Length
- 2.25 m
Reading the result
The result solves for length from the entered quantities. Check the result unit and the formula conditions before using it.
Questions and answers
Can I use the example values for my own calculation?
The example values illustrate the calculation. Replace every input with your own information, especially dates, rates and the selected operation.
When can I use the length result?
This model uses positive magnitudes. Cross section and material are uniform along the conductor. Contact resistance and temperature changes are excluded.
Why are some results rounded?
Results display up to 8 decimal places. Calculations use the unrounded values; very small values use scientific notation. JavaScript floating-point arithmetic can introduce tiny rounding differences.
Are my inputs sent to a server?
The calculator processes inputs in your browser. Its code does not send your values to a server.
Method sources: openstax.org