Copper aluminium cable comparison calculator
Compare Australian copper and aluminium cable candidate records from entered resistance, route length, current and material cost values.
Vdrop = 2 x I x Lkm x Rkm; Ploss = I x Vdrop; material_cost = cost_per_m x length; difference = aluminium - copper for drop and loss- Copper and aluminium resistance values are entered by the user.
- Cost values are optional project handoff values, not supplier feeds.
- The calculation compares candidate records only.
- It does not decide conductor material or cable selection.
| Variable | Meaning | Unit | Use |
|---|---|---|---|
| I | Load current | A | Entered current for both candidate records. |
| Lkm | Route length | km | One-way route length converted from metres. |
| Rcu | Copper resistance | ohm/km | Entered copper candidate resistance. |
| Ral | Aluminium resistance | ohm/km | Entered aluminium candidate resistance. |
| Vdrop | Voltage drop | V | Calculated voltage drop for each candidate. |
| Ploss | Cable loss | W | Current multiplied by voltage drop. |
| material_cost | Material cost | AUD | Entered cost per metre multiplied by route length. |
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Copper aluminium cable comparison calculator technical guide
Compare Australian copper and aluminium cable candidate records from entered resistance, route length, current and material cost values.
Use this calculator when two candidate cable records have been entered for the same route and the reviewer needs a transparent copper versus aluminium comparison. The page compares voltage drop, loss and entered material cost. It does not select conductor material.
Field use cases
| Work setting | Real question | Useful action from this page |
|---|---|---|
| Feeder candidate review | How different are the entered voltage drops? | Compare copper and aluminium drop side by side. |
| Cost handoff | What is the entered material-cost difference? | Multiply each cost per metre by the same route length. |
| Operating loss discussion | Does one candidate create materially higher loss? | Compare loss watts before annual cost modelling. |
| Procurement review | Which assumptions need a source check? | Keep resistance and cost source values visible. |
| Design conversation | Is the trade-off worth deeper review? | Carry the comparison into cable, termination and installation review. |
The calculator is useful only after both candidate data sets have been identified. It is not a substitute for a cable schedule.
Data checklist
| Value | Where it normally comes from | Stop if |
|---|---|---|
| Copper resistance | Cable data source or project schedule | The value belongs to another size or temperature basis. |
| Aluminium resistance | Cable data source or project schedule | The comparison is between unrelated candidates. |
| Current and voltage | Design record or load calculation | The route basis differs between candidates. |
| Route length | Drawing, takeoff or measured route | The candidates do not follow the same route. |
| Cost per metre | User-entered project or supplier assumption | The cost is being treated as a live quote without source. |
Cost and resistance are intentionally entered manually. That keeps the source trail visible and avoids pretending to have a complete supplier or standards table.
Method comparison matrix
| Method element | What this calculator does | What remains outside |
|---|---|---|
| Voltage drop | Calculates drop from entered resistance, current and route length. | Choosing the correct resistance value. |
| Loss watts | Multiplies current by voltage drop. | Annual energy, duty cycle and tariff modelling. |
| Material cost | Multiplies entered cost per metre by route length. | Live pricing, procurement, freight and stock availability. |
| Comparison status | Flags material differences for review. | Final conductor material or cable-size decision. |
Use the comparison to make trade-offs visible without turning the worksheet into a final material recommendation.
Worked records
| Situation | Inputs | Result | Record use |
|---|---|---|---|
| Feeder comparison | 80 A, 400 V, 70 m, entered copper and aluminium resistance | Copper about 2.04%, aluminium about 3.22% | Carry loss and cost trade-off into review. |
| Short branch | 32 A, 230 V, 18 m | Small electrical difference | Keep record with candidate source data. |
| Long run | 125 A, 400 V, 120 m | Larger drop and loss difference | Review conductor and installation assumptions. |
The examples use deliberately visible source values. Replace them with project data before relying on the worksheet.
Stop points
- Candidate resistance values are not on the same basis.
- The two candidates do not serve the same route or load.
- Cost values are stale or not sourced.
- The result is being used as a recommendation to choose copper or aluminium.
- Termination, bending, installation method and current capacity have not been reviewed.
A useful export record includes candidate source notes, route length, current, voltage, both resistance values, both drop results, loss difference, cost difference and reviewer.
Feeder candidate comparison
A reviewer compares two user-entered conductor records for the same run before a separate cable-size review.
- Comparison reference
- CU-AL-RUN-1
- Current
- 80 A
- Route length
- 70 m
- Copper resistance
- 0.727 ohm/km
- Aluminium resistance
- 1.15 ohm/km
- Copper drop8.14 V, or 2.04%.
- Aluminium drop12.88 V, or 3.22%.
- Loss and cost379.01 W loss difference and 245 AUD entered material-cost difference.
Use the difference record as an input to a separate cable and installation review.
The aluminium record has higher drop and loss but lower entered material cost. Keep the data source visible before selection review.
- Resistance and cost values are entered by the user.
- The page compares two candidate records only.
- Current capacity, terminations, installation and procurement remain separate.
Short branch comparison
A short route has small electrical differences but still needs cost and source records attached.
- Comparison reference
- SHORT-BRANCH-1
- Current
- 32 A
- Route length
- 18 m
- Copper resistance
- 1.15 ohm/km
- Aluminium resistance
- 1.85 ohm/km
- Copper drop1.32 V, or 0.58%.
- Aluminium drop2.13 V, or 0.93%.
- Loss and cost25.8 W loss difference and 23.4 AUD entered material-cost difference.
Use the difference record as an input to a separate cable and installation review.
Electrical differences are modest on the short run, but the comparison still depends on entered project data.
- The route is treated as a two-conductor voltage-drop comparison.
- The cost values are not supplier quotes unless the user enters current quote data.
- Mechanical and termination suitability are outside the calculation.
Long run review
A longer run highlights larger loss and voltage-drop differences between entered conductor records.
- Comparison reference
- LONG-CU-AL-1
- Current
- 125 A
- Route length
- 120 m
- Copper resistance
- 0.524 ohm/km
- Aluminium resistance
- 0.868 ohm/km
- Copper drop15.72 V, or 3.93%.
- Aluminium drop26.04 V, or 6.51%.
- Loss and cost1290 W loss difference and 720 AUD entered material-cost difference.
Use the difference record as an input to a separate cable and installation review.
The larger route makes loss, drop and cost differences more material, so the comparison should feed a documented review.
- The entered resistance values are already appropriate to the candidates being compared.
- No controlled standards table is reproduced.
- Competent review controls whether either candidate proceeds.