Free Tool

Size Wire With Confidence

Estimate conductor size and voltage drop for common electrical runs. Check copper vs aluminum options and avoid surprises during installation.

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Wire sizing calculator showing recommended gauge and voltage drop results

Practical Electrical Sizing Checks

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Voltage Drop %

Quickly see whether a run stays within your target voltage drop.

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Wire Gauge Recommendations

Estimate a gauge that fits the load and run length constraints.

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Copper vs Aluminum

Compare conductor materials and see how they affect voltage drop.

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Installation-Friendly

Get results you can use during planning, quoting, and field work.

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Conduit Fill Awareness

Include conduit fill checks as part of your sizing workflow.

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Private by Default

Runs in your browser. No account and no upload of job details.

Wire Sizing Features

Voltage Drop Calculation for Real Runs

Enter load and distance and see the expected voltage drop quickly so you can choose the right conductor size.

  • Drop in volts and %
  • Useful for long runs
  • Fast comparison across gauges
Voltage drop results across wire gauge options

Gauge Selection and Material Comparison

Compare copper and aluminum conductors and find a practical gauge that meets constraints for the job.

  • Copper vs aluminum
  • Quick “what-if” checks
  • Planning and quoting support
Recommended gauge selection for a given load

Derating and Conduit Fill Helpers

Include common derating considerations and conduit fill checks to keep plans realistic.

  • Derating awareness
  • Conduit fill workflow
  • Reduce rework during install
Conduit fill and derating helper outputs

Common Questions

Targets vary by application and local standards. A common rule of thumb is to keep branch circuits low (often a few percent) and keep the total drop reasonable across feeders and branch circuits.
No—use it for fast estimation and sanity checks. Final designs should follow applicable codes, project specs, and professional review where required.
No. Everything runs in your browser and inputs are not sent to a server.

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