Parallel Wire Calculator

For N identical conductors in one current path, resistance divides by N: Rpath = Rsingle/N.

The equivalent conductive area per path is Aeq = N × A, where A is the area of one conductor.

First calculate one conductor resistance with Rsingle = ρL/A. Then divide by the parallel count: Rpath = Rsingle/N.

In the ideal identical-conductor model, current per conductor is Iper = Itotal/N.

Identical conductors have equal resistance in the ideal model, so equal voltage across each branch produces equal current.

They share equally only under the ideal assumptions of matched resistance, length, routing, temperature, and connection resistance.

Current will not divide equally. Lower-resistance conductors carry more current, requiring a conductance-based network model outside this V1 calculator.

Not in this calculator. V1 assumes identical conductors with the same size, material, length, and resistance.

No. Mixed materials are outside the identical-conductor model and can produce unequal current sharing.

It means the number of identical conductors in each current-carrying path. In a two-wire DC loop, N outbound conductors and N return conductors are modeled.

In the standard two-conductor loop model, entering N = 2 means 2 outbound conductors and 2 return conductors, for 4 physical conductors total.

Physical total conductor length is Lphysical = 2NL, where L is one-way run length and N is conductors per path.

For fixed total current, matched material, matched length, and the same conductor size, increasing N lowers loop resistance and voltage drop in proportion to 1/N.

For fixed total current, total I²R conductor loss decreases in proportion to 1/N because loop resistance decreases in proportion to 1/N.

For fixed total current and identical conductors, current density per conductor decreases in proportion to 1/N.

Equivalent conductor area is the total conductive area in one current path. It is N times the area of one conductor.

Electrically, in the ideal DC resistance model for one current path, four identical 2.5 mm² conductors have 10 mm² equivalent conductive area.

No. Equivalent area only describes the ideal DC resistance model. Thermal behavior depends on spacing, bundling, insulation, cooling, and installation details.

Not automatically. Real ampacity depends on code rules, installation method, bundling, ambient temperature, insulation rating, termination rating, and derating.

No. It does not check ampacity, safe current, electrical-code compliance, fuse sizing, breaker sizing, or installation derating.

No. Terminal, lug, connector, and busbar contact resistance are not included.

Yes. Temperature changes resistance, so unequal heating can cause unequal current sharing in real systems.

Yes. Different lengths produce different resistance, so current no longer divides equally.

Only as a low-frequency resistive approximation. It does not model skin effect, proximity effect, inductive imbalance, or high-frequency current distribution.

No. Three-phase feeder sizing requires phase conventions, installation rules, standards, and often code-specific derating.

No. Results are mathematical engineering estimates only and are not NEC, IEC, UL, or code-approved conductor sizing.

N = 1 is valid and reduces to the ordinary single conductor per path two-wire loop model.