Verify the inputs
Measure or document each input. If a value is only an estimate, record its source and test a conservative alternative.
Electrical power/ CALCULATOR
DC cable voltage drop
Estimate copper-cable voltage drop, percentage loss and heat at a steady current.
FROM ESTIMATE TO ACTION
Use the result, not just the number.
Keep the calculation traceable
Save the input link or copied result together with the date, units and assumptions. A number without its inputs cannot be checked later.
Confirm the decision
Compare the estimate with the related guide, current product data and requirements that apply at your location before buying or building.
Inputs to verify
- One-way cable length (m)
- Measure from the source to the load; the formula includes the return conductor.
- Steady design current (A)
- Use a realistic continuous operating current, not only a device label.
- Copper conductor area (mm²)
- Use the actual conductor cross-sectional area.
- System voltage (V)
- Nominal DC system voltage.