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Electrical

What it's for

A rough-in takeoff for pricing and ordering. List the rooms and the big electric appliances, and you get a count of outlets, GFCI outlets, switches, circuits and panel spaces, plus a material list of devices, breakers, cable and boxes. It is an estimate, not a code check: nothing on the results card passes or fails, and the screen does not know where your doors, windows or counters are.

Step by step

The example is the screen as it opens: one 12' 0" × 10' 0" bedroom, no electric appliances, one HVAC circuit.

Electrical inputs: ROOMS with ROOM 1 and its trash button, ROOM TYPE Bedroom, LENGTH 12' 0", WIDTH 10' 0", then ADD ROOM, ELECTRIC RANGE off, ELECTRIC DRYER off, ELECTRIC WATER HEATER off, HVAC CIRCUITS 1 with HVAC 1 MCA and HVAC 1 MOCP both not entered under the note MCA and MOCP from each unit's nameplate size its wire and breaker (NEC 440.4(B)), and WASTE FACTOR 10%. There is no PLAN SHOWS row, because it appears only once there are two rooms. The answer bar reads 8 outlets, 0 GFCI · 1 switch. 1 2 3 5 6 7
Steps 1–3 and 5–7 are the inputs. Step 5 covers all three appliance switches. Step 4, PLAN SHOWS, appears once a second room is added, and is described below.
  1. ROOM TYPE — pick from Kitchen, Living, Dining, Bedroom, Bathroom, Laundry, Hallway and Garage. The type sets how closely the outlets are spaced, whether they count as GFCI, and how many switches the room gets.
  2. LENGTH and WIDTH — the room, wall to wall at the floor. The example is 12' 0" by 10' 0". There is no height. Only the perimeter and the floor area are used.
  3. Tap Add Room for every room on the job. Rooms are numbered, not named. The bin beside a ROOM heading deletes that room.
  4. PLAN SHOWS appears once there are two rooms or more. Pick the room the plan draws: Room 1, Room 2 and so on, as buttons up to four rooms and a menu past that. It starts at Room 1. The pick is kept with your inputs, so a result you open again from History shows the same room.
  5. ELECTRIC RANGE, ELECTRIC DRYER and ELECTRIC WATER HEATER — switch on each one the house has. Each adds one dedicated 240 V circuit to the order: a 2-pole breaker, its cable and, for the range and dryer, its receptacle.
  6. HVAC CIRCUITS — how many dedicated circuits the heating and cooling equipment needs. It opens at 1. Set 0 if there are none. Each circuit then takes the MCA and MOCP from its unit's nameplate (NEC 440.4(B)): the minimum circuit ampacity sizes the wire and the maximum overcurrent protection sets the breaker, so an MCA of 18 A and an MOCP of 30 A order 12/2 NM-B on a 30 A 2-pole breaker. Left at not entered, the circuit is counted but not sized. An MOCP under the MCA is refused: read the nameplate again.
  7. WASTE FACTOR — extra to order, in steps of 5%. The example is 10%. It changes the MATERIALS list only, never the counts in RESULTS.
  8. Read RESULTS: 8 outlets, 0 GFCI · 1 switch, 3 circuits (1 dedicated, 2 AFCI), 6 panel spaces needed.
  9. Tap BASIS & WHAT WAS ASSUMED and read it before you price from these counts.
  10. Scroll down to the plan of the room PLAN SHOWS picks (ROOM 1 in the example) and the panel.
  11. Read MATERIALS for the order.

Reading the results

Electrical results: the answer bar keeps 8 outlets and 0 GFCI · 1 switch. The end of the inputs (HVAC 1 MCA and HVAC 1 MOCP not entered, WASTE FACTOR 10%) is above RESULTS, which reads 0 GFCI · 1 switch, 3 circuits (1 dedicated, 2 AFCI) and 6 panel spaces needed, then the BASIS & WHAT WAS ASSUMED row and the link Check before you cut · Measure twice. The plan below shows a 12' 0" by 10' 0" BEDROOM with eight outlet circles and its door, a PANEL schedule, and an inset headed NEC 210.52(A) REACH dimensioned 6' 0". Its notes read ROOM 1 · BEDROOM · 12' 0" × 10' 0" · 120 SF; 8 RECEPT (○) @ 5' 6" MAX · 1 SW · PERIM 44' 0"; PANEL 6 SPACES · 2×1P + 1×2P + 2 SPARE; JOB 8 OUT · 0 GFCI · 1 SW · 3 CKT · 10 BOXES; SCHEMATIC: DOOR, SWITCH + PANEL — NOT DIMENSIONED. 8 9 10
Steps 8–10: the counts, the basis row, and the plan of room 1.
Electrical scrolled to the end: the plan's notes and its title strip ELECTRICAL PLAN, 5' 6" MAX, NOT TO SCALE, then MATERIALS listing Receptacles 9 pcs; Switches 2 pcs; AFCI breakers (1-pole) — NEC 210.12(B): kitchen, living, dining, bedroom, hall, laundry circuits 2 pcs; Breakers (2-pole) — 240V loads — verify pole count for HVAC (120V air handlers take 1-pole) 1 pcs; NM-B cable (14/2 & 12/2 mix) — ~20 lf per device — long homeruns: check Voltage Drop calc 198 lin ft; and Device boxes 10 pcs. Under them a dimmed SHARE PDF with a list icon at its right end sits beside a lit SAVE, over the line Enter your own measurements to export. 11
Step 11: the order, with waste added.

The headline is the total outlets. Each room's perimeter is walked at the spacing for its type, and every room gets at least one.

GFCI and switches. Every outlet in a Kitchen, Bathroom, Laundry or Garage is counted as a GFCI device. Each room gets one switch. A Hallway gets two, one at each end, and MATERIALS buys them as a pair of 3-way switches with a note to run 14/3 between them.

Circuits is general receptacle circuits, plus lighting circuits worked from the floor area, plus the dedicated ones. Kitchens (two each), bathrooms, laundries and garages (one each) set a minimum for the receptacle circuit count. They are not added on top of it. Dedicated is your appliance switches plus HVAC CIRCUITS. In the example the one dedicated circuit is the HVAC. AFCI counts the 120 V circuits that need arc-fault breakers: NEC 210.12(B) covers kitchens, living and dining rooms, bedrooms, hallways and laundry areas. Once the job has one of those rooms, every 120 V circuit is priced AFCI except one bathroom and one garage circuit per room. In the example both of the bedroom's circuits are AFCI.

Panel spaces needed counts two spaces for each dedicated circuit, one for each of the others, and two spare. The drawing spells it out. In the example: PANEL 6 SPACES · 2×1P + 1×2P + 2 SPARE.

BASIS & WHAT WAS ASSUMED opens with Counts run ~2× NEC minimums; all wet-area outlets priced as GFCI devices. So the device counts are generous on purpose, and the GFCI count assumes a GFCI device at every wet-area outlet rather than one device protecting the rest downstream. Trim the order to suit how you wire. The next lines say which circuits are AFCI and how the appliance circuits are sized, and the last names the NEC edition the sections come from (2023).

The drawing is a plan of one room, the one PLAN SHOWS picks (ROOM 1 when there is only one), with the outlets as circles around the walls, and a panel schedule beside it. The notes under it give the room and its number, ROOM 2/3 for the second of three, the outlet count and spacing used — 8 RECEPT (○) @ 5' 6" MAX · 1 SW · PERIM 44' 0" in the example — the panel make-up, and the job totals. A note says the door, switch and panel are schematic and not dimensioned. The screen does not know where they are. The boxed inset is headed NEC 210.52(A) REACH and draws the code's rule: no point on the wall more than 6' 0" from an outlet, so the dimension runs 6' 0" from the first outlet back toward the corner. That puts outlets up to 12' apart. The screen spaces them closer than that on purpose. Pinch to zoom, drag to move around, double-tap to reset, or tap the expand button at its top right for the whole screen. See Reading the drawing.

MATERIALS is the order: receptacles, GFCI receptacles when there are any, switches, AFCI and plain 1-pole breakers, 2-pole breakers, cable and device boxes. Waste is added to the devices, cable and boxes and rounded up. Breakers are one per circuit, with no waste. Each appliance you switched on adds its own rows: a range gets NM-B 6/3 w/G (range, 50 A) and a Receptacle 14-50R, a dryer NM-B 10/3 w/G (dryer, 30 A) and a Receptacle 14-30R, and a water heater NM-B 10/2 w/G (water heater, 25–30 A), hard-wired. The cable is the smallest copper the NEC 310.16 60 °C column rates for the breaker. Each run is a rule of thumb of 50' plus waste. Measure yours, and size a water heater from its nameplate in Water Heater. Two rows carry their own warnings. The 2-pole breaker row says to verify the pole count for HVAC, because every dedicated circuit is priced as 2-pole. The cable row is a rule of thumb of about 20 lineal feet per device and says to check long homeruns in Voltage Drop.

The buttons wait for your own numbers: the export button and the list icon in it stay dimmed, and SAVE tells you to enter them first. After that SHARE PDF shares the plan, the counts, the rooms and the materials, the list icon at the right end of the same button shares the material list alone, and SAVE puts the result in History. The PDF lists every room, running onto more pages when it needs them. Its first page draws the room PLAN SHOWS picks, and every other room's plan follows on a page of its own, headed ROOM 1 PLAN, ROOM 3 PLAN and so on. Its footer reads Estimate — verify dimensions and local code before cutting/ordering. Your local code and your inspector govern the real layout.

Electrical is a Pro calculator. The PDF and History are Pro too. Pro is a one-time purchase. See Free and Pro.

Common mistakes