Wire Size Estimator & Reference
Estimate a minimum wire size based on load current, conductor type, and whether the load is continuous.
Use the estimator for a quick starting point, then compare copper and aluminum typical reference sizes below.
Enter the load details to estimate a minimum wire size.
Estimated result
Sizing amps used
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Recommended minimum wire size
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Thicker wire generally carries more current. Smaller AWG numbers mean thicker wire.
How to read wire size
Smaller AWG number means thicker wire
Thicker wire generally carries more current
Continuous loads are often sized above the actual running amps
Wire type, insulation, temperature, bundling, and code all matter
Common wire size reference
14 AWG
Typical reference: 15 amps
Common for 15-amp lighting and outlet circuits.
12 AWG
Typical reference: 20 amps
Common for 20-amp kitchen, bath, and general-use circuits.
10 AWG
Typical reference: 30 amps
Often used for water heaters, dryers, and other larger loads.
8 AWG
Typical reference: 40 amps
Common for larger appliances and some subfeeders.
6 AWG
Typical reference: 55 amps
Often used for ranges, EV equipment, and larger feeders.
4 AWG
Typical reference: 70 amps
Common for heavier feeder runs and larger subpanels.
2 AWG
Typical reference: 95 amps
Used when the load is too large for typical branch-circuit wire sizes.
Aluminum typically requires a larger size than copper for the same load. These are typical reference values for planning only. Actual ampacity depends on insulation, temperature rating, bundling, terminals, and code requirements.
This estimator is a quick planning reference only. Actual wire sizing depends on the application, insulation type, temperature rating, bundling, voltage drop, and local code requirements. When in doubt, check with a licensed electrician.
Related problems and reference
Planning and safety note
This content is for general learning and planning. Always verify work against current NEC requirements, manufacturer instructions, and local code rules. If you are unsure or see heat, sparks, burning smell, repeated trips, or damaged wiring, contact a licensed electrician.