Voltage Drop

From input to answer.

Choose your electrical region in Settings, then open All Tools → Voltage Drop.
Select what to solve for and the circuit configuration.
Enter supply voltage, current and one-way run length as applicable. Check conductor material, installation, power factor, temperature and target percentage.
Read voltage drop and estimated load voltage, or the solved size/length/current. Review the calculation basis before using the answer.

WORKED EXAMPLE

A Canada-mode sizing example

Enter

Choose conductor size, single-phase line-to-neutral, 120 V, 20 A, 30 m one-way, 3% target, copper in raceway, 100% power factor and 75°C.

Read the result

The app selects 8 AWG for this voltage-drop check: 3.048 V, or 2.54%, leaving an estimated 116.952 V at the load. This is not an ampacity or protection approval.

Get more from it.

Enter one-way length; the selected circuit factor accounts for the relevant return path.
Canada mode uses CEC 2024 data. US mode provides NEC-based methods, including the app’s NEC 2026 reference data.
Check the selected method: AC impedance, DC resistance and a K estimate make different assumptions.

Know the limits.

Steady-load voltage drop does not cover motor starting, every unbalanced system, conductor ampacity or overcurrent protection.
The applicable code edition and local amendments must be confirmed for the installation. Meeting a chosen percentage does not establish compliance.

Verify the inputs, applicable local requirements and real conditions. The app is a calculation aid and can contain errors. See our terms and safety disclaimer.

Common questions.

Is there a US option?

Yes. Change the electrical region to US for the NEC voltage-drop workflow. The Canada-only sizing tools are separate.

Why might another calculator give a different size?

Method, material, temperature, power factor, raceway and circuit assumptions can change the result.