Batch Wire Sizing Calculator
// PASTE OR UPLOAD CSV SCHEDULES TO BATCH-CHECK CONDUCTOR SIZE RECOMMENDATIONS FOR FEEDERS AND BRANCH CIRCUITS //
Paste a clean CSV schedule or upload a file with one row per circuit. This tool screens each row against 75°C ampacity and an allowable voltage-drop target.
circuit, current_amps, voltage, length_ft, material, phase, max_drop_percentUse one-way length in feet. This parser expects simple comma-separated cells without quoted commas inside values.
Results are planning-grade recommendations. Use the related single-circuit tools below when a row needs temperature derating, conduit fill review, resistance checks, or a full cable-sizing pass.
| Circuit | Input | Recommended | Status |
|---|---|---|---|
Detached garage feeder copper / single-phase | 60 A 240 V 145 ft one-way 3% max drop | 6 AWG 65 A ampacity 6.87 V drop 2.86% actual drop | Fit found |
Level 2 EV charger copper / single-phase | 48 A 240 V 110 ft one-way 3% max drop | 8 AWG 50 A ampacity 6.63 V drop 2.76% actual drop | Fit found |
Parking lot lighting aluminum / three-phase | 20 A 277 V 180 ft one-way 3% max drop | 8 AWG 40 A ampacity 6.43 V drop 2.32% actual drop | Fit found |
Well pump copper / single-phase | 28 A 240 V 225 ft one-way 5% max drop | 8 AWG 50 A ampacity 7.91 V drop 3.30% actual drop | Fit found |
This tool sizes from the smallest listed conductor upward and accepts the first gauge that passes both screens: 75°C ampacity and the row's maximum voltage-drop percentage.
Resistance values are based on standard conductor data at 20°C. For single-phase rows, the calculator uses a round-trip conductor factor. For three-phase rows, it uses the square-root-of-three voltage-drop relationship.
It does not apply ambient-temperature correction, conductor bundling adjustment, terminal temperature limitations, or local code amendments. Use it to batch-screen schedules, then confirm final design conditions.
A failed row usually means the allowable drop is too strict for the system voltage and distance, or the load exceeds the supported conductor range.
Common fixes are increasing conductor size, shortening the run, increasing system voltage where appropriate, or splitting the load across feeders or branch circuits.
When you are close to the threshold, verify the row in the dedicated tools below before you issue a schedule or release material for purchase.
Re-check a flagged row with a dedicated single-circuit drop calculation.
Apply conductor temperature and bundling derating before final selection.
Verify raceway sizing after your batch schedule settles on conductor sizes.
Use a more detailed cable-sizing workflow for final design decisions.
Inspect conductor resistance directly for edge-case circuits and troubleshooting.
Estimate spool weight and handling loads for the recommended conductors.