Electrical takeoff for new circuits

Every line shows the quantity to buy and how StudSheet got it: the spacing, the waste and the package size, so you can check it before the supply house or the quote.

In Canada (3 circuits)

Set to Canada, the Sheet works the job out again for Ontario: metric sizes, bag sizes, the frost depth and the code notes. It doesn't just convert feet to meters. The first lines:

• 156.97 m — 3 × 75 m coils, NM cable 14/2 with ground: General receptacles: 3 × (12.19 m home run + 7 × 4.27 m between boxes + 5.49 m slack) + 10%. Slack: 914 mm at the panel and 305 mm for every cable end in a box.
• 24 boxes, Single-gang box, new work: One per receptacle and switch, each sized for its conductors and device (the CEC box-fill tables).
• 24 receptacles, Receptacle, 15 A tamper-resistant: 24 for general receptacles. Tamper-resistant throughout a home.
• 24 plates, Wall plates, single-gang: One per device.
• 3 breakers, AFCI breaker (combination type): 3 for general receptacles (arc-fault). Only breakers listed for this panel’s brand and type.
• 2 packs of 100, Cable staples (100): About 153 staples: within 300 mm of each box and every 1.5 m.

1. Check the panel and the service: 3 spaces needed, 8 open.
2. Pull the electrical permit (electrical subcode) from the town’s construction office.
3. Lay out the boxes and home runs; mark which panel spaces each circuit takes.
4. Rough-in: boxes, NM-B, supports and connectors as listed.
5. Rough-in inspection before cover — no insulation or drywall until it passes.
6. Trim-out: devices, plates and breakers (AFCI and GFCI as listed).
7. Test every circuit: polarity, GFCI and AFCI trip, and terminals torqued to the label.
8. Label the panel directory with each new circuit’s purpose (NEC 408.4).
9. Final inspection; give the client the approval.

Must-have tools first, then the ones that help and the ones to rent for the day.

Mistakes that cost a callback or a second trip

• Covering before the rough-in inspection: Insulation or drywall over uninspected wiring gets opened back up at your cost.
• Breakers that aren’t listed for the panel: Another brand’s breaker that “fits” voids the listing and fails inspection. Match the panel’s label.

What the calculator assumes

• Small conductors: 14 AWG copper on 15 A, 12 AWG on 20 A, 10 AWG on 30 A at most (NEC 240.4(D)); breakers in the standard sizes of 240.6(A).
• Ampacity: NM-B at the 60 °C column (NEC 334.80); MC and THHN at 75 °C on circuits over 30 A where both ends are rated 75 °C (110.14(C)), Table 310.16.
• Continuous loads at 125%: EV chargers at their setting (NEC 625.41, 625.42) and storage water heaters at the nameplate (422.13).
• AC and heat pumps: conductors from the nameplate MCA, breaker no larger than the MOP (NEC 440.4(B), 440.22, 240.4(G)).
• Cable per circuit: the home run + the cable between boxes (lighting 8 ft, receptacles 14 ft, kitchen 6 ft, bath and laundry 8 ft) + 3 ft at the panel + 1 ft per cable end in a box, + 10% for the route.
• Voltage drop: over the home run at 80% of the breaker (EV, water heater and AC at their load; past the first box the load spreads out), copper at 75 °C (NEC Chapter 9 Table 8); 3% in a branch circuit is the NEC’s suggestion, not a rule.
• Supports: NM-B within 12″ of each box and every 4½ ft (NEC 334.30); 1¼″ from the stud face or a steel plate (300.4(A)).
• AFCI and GFCI follow the NEC 2020 (210.8, 210.12); local amendments win.
• Labor: typical production rates for open framing with NM-B; your crew’s numbers win.

The Sheet sets its code notes for the job's state or province. These are New Jersey's and Ontario's; the code reference has more. Always confirm with your building department.

• Licensed electrical work: permit and inspections: New circuits need an electrical permit (the electrical subcode) from your town’s construction office, filed by an electrical contractor licensed by the NJ Board of Examiners of Electrical Contractors — the license number and seal go on the application. The owner of a single-family home may do electrical work on the home they own under a homeowner permit (N.J.A.C. 5:23-2.15), inspected the same way. Rules change — your town’s construction office has the last word.
• Code: NEC 2020: New Jersey enforces the NEC 2020 (N.J.A.C. 5:23-3.16, with New Jersey’s changes). Towns can amend it. Rules change — your town’s construction office has the last word.
• AFCI and GFCI (NEC 2020): General receptacles: AFCI breaker — bedrooms and living areas (210.12(A)). New Jersey deletes the AFCI rule for extending existing circuits (210.12(D)); new circuits still follow it.
• Labor by circuit type: General receptacles × 3: 14.5 h; testing, labels and inspections 1.5 h.
• Code: Ontario Electrical Safety Code 2024: Ontario enforces the 2024 Ontario Electrical Safety Code (CEC 2024 with Ontario amendments, in force May 1, 2025). The Sheet follows the CEC 2024 rules; check your province’s amendments.
• AFCI and GFCI (CEC 2024): General receptacles: AFCI breaker — receptacle circuits (Rule 26-658).

What materials do I need to run new electrical circuits?

For the worked example, a 3 circuits, the Sheet counts 8 lines with waste included, starting with nM cable 12/2 with ground (515 ft — 2 × 250 ft rolls + 1 × 25 ft roll), single-gang box, new work (24 boxes), receptacle, 20 A tamper-resistant (24 receptacles), wall plates, single-gang (24 plates). Each line's math is in the table above. Put in your own sizes in the circuits calculator and every line is counted again.

How long does it take to run new electrical circuits, and can I do it myself?

About 14 to 21 hours for the worked example, in 9 steps. StudSheet stamps it PRO JOB: hire this out (pros get the full Sheet).

What tools do I need to run new electrical circuits?

16 in all. The must-haves start with non-contact voltage tester, digital multimeter, lockout/tagout kit, wire strippers, lineman’s pliers, insulated screwdrivers (1000 v). On the Sheet you mark each one as owned, to buy or to rent.

Stuck while you run new electrical circuits? Ask in the Circuits and wiring group of the StudSheet community with this Sheet attached. Homeowners who've done it and verified pros answer, and anyone can read it.

• Electrical for contractors: run this takeoff at your own prices, send the estimate, and get it signed and the deposit paid.
• Panel or service upgrade (100 A to 200 A service): For electricians: panel, breakers, service cable, grounding, and the utility and permit steps.
• All 45 Sheets, across 16 trades.
• Code reference: frost depths, guard heights, stairs, retaining walls.