A homeowner's kitchen is running three extension cords and they want to add a circuit. Another customer has a 100-amp service and is adding a new addition with HVAC and 240-volt equipment — they need a full 200-amp panel upgrade. A builder is framing a new house and needs rough-in pricing for the whole place. Three jobs, three dramatically different estimates, and getting them wrong costs you thousands.
Electrical work is among the highest-stakes estimates contractors do. You're responsible for safety, code compliance, and longevity. You also need to price the labor accurately — rough-in in open framing is efficient work, but retrofitting circuits through finished walls and crawlspaces is slow. Material costs are stable (copper wire and breakers don't fluctuate much), but labor time swings wildly based on the scope.
This guide covers electrical estimating for the major job types: new rough-in, panel upgrades, full rewires, and adding circuits. If you're already familiar with general pricing, this will give you the electrical-specific framework. If you're not a licensed electrician, use this to understand your sub's pricing.
Understanding Electrical Load and Service Size
Before you estimate any electrical work, understand the load. If you undersell a panel upgrade and find out halfway through that the calculation was wrong, you're left doing expensive change orders or eating the cost of a bigger panel.
Load Calculation Basics
Electrical load is measured in amps. Residential service typically runs 100, 150, or 200 amps. Here's what you need to know:
- 100-amp service: Entry-level residential, older homes, small houses or simple additions. Adequate for basic loads (lights, outlets, standard appliances), but struggles with HVAC, electric heat, or multiple large loads at once.
- 150-amp service: Mid-range residential, newer homes, medium houses. Can handle HVAC, most appliances, and some dedicated circuits for heavier loads.
- 200-amp service: Modern standard for new construction and upgrades, larger homes, any house with electric heat or high-demand equipment like large HVAC, hot tub, or EV charger.
To calculate what a house needs, the NEC (National Electrical Code) has a formula based on square footage, plus additional load for specific equipment. A typical calculation:
- Base load: 3 watts per square foot (1,000 sq ft = 3,000 watts or 25 amps at 120V). For a 2,000 sq ft house, that's 6,000 watts or 50 amps.
- Heating/cooling: Add the full load for the largest single load (HVAC, electric heat, or cooling). A 4-ton AC system draws about 40-50 amps.
- Major appliances: Electric stove (40-50 amps), water heater (30-40 amps), dryer (20-30 amps). These are added as peak loads, not all at once.
- Add 25% for growth and simultaneous demand
New Construction Rough-In Estimating
Rough-in is running wire, boxes, and conduit through open framing before drywall and flooring. It's the most efficient electrical work because you have access to stud bays and joist spaces.
Materials for Rough-In
Material cost breaks down into wire, boxes, breakers, conduit, and misc hardware:
- Wire (Romex or NM cable for residential branch circuits) — $0.05-$0.12 per foot depending on gauge. 12-gauge (15-amp) is common for outlets, 10-gauge (20-amp) for kitchens, 8-gauge (40-amp) for dryer.
- Boxes (outlet boxes, switch boxes, junction boxes) — $0.50-$2.00 each depending on type. A typical house might have 40-60 outlet and switch boxes.
- Breakers (standard single-pole 15 or 20 amp) — $5-$15 each. A new house might have 30-50 breakers; main breaker is $50-$150.
- Panel (200-amp main panel) — $300-$600 depending on type and number of spaces.
- Conduit and misc (for outdoor runs, service entrance, protection) — $0.30-$1.50 per foot.
Labor Time for Rough-In
Rough-in labor depends on house size, complexity, and how much coordination is needed with other trades:
- Simple house (1,500-2,000 sq ft, single story, simple layout): 24-32 hours for full rough-in
- Standard house (2,000-3,000 sq ft, 1.5-2 story, typical layout): 32-48 hours
- Complex house (3,000+ sq ft, complex layout, multiple levels, lots of circuits): 50-70 hours
- Service entrance and main panel installation: add 4-6 hours
- Rough-in labor rate for a journeyman electrician: $60-$90/hour depending on market and experience
A 2,000 sq ft house at 28 hours labor (2 electricians, 2 weeks of part-time work, or 1 electrician 4 days) at $75/hour labor = $2,100 in labor. Total rough-in cost: ~$3,300-$3,400.
Panel Upgrade Estimating
A panel upgrade is replacing the main panel, disconnecting the old one, installing the new one, and running new service entrance wire and conduit if needed. This is a big job that requires careful estimation.
Components of a Panel Upgrade
- Service entrance wire (from meter to main panel) — usually needs upgrading from 2-gauge to 2/0 or larger for 200-amp service. 100 linear feet might cost $300-$600 in wire.
- Main panel and breakers — $400-$800 for a 200-amp panel, plus individual breakers ($8-$15 each) for new circuits.
- Disconnect/removal of old panel — labor to safely disconnect all circuits and remove the old panel. Usually 2-4 hours.
- Installation of new panel — running service entrance wire, installing meter base (sometimes replaced, $100-$300), installing main breaker, setting new panel. Usually 6-10 hours.
- Code upgrades — some jurisdictions require AFCI or GFCI breakers as part of an upgrade. Budget $15-$25 per breaker for these upgraded types.
- Permits and inspection — $100-$300 depending on jurisdiction.
Labor Time and Cost Estimate
A 100-amp to 200-amp panel upgrade (removing old service, installing new meter base, new panel):
- Disconnection and removal: 2-3 hours
- Installation and setup: 8-10 hours
- Testing, breaker installation, final inspection: 2-3 hours
- Total labor: 12-16 hours at $75/hour = $900-$1,200
Full House Rewire Estimating
A full rewire is replacing all wiring in a house — often done in older homes with knob-and-tube wiring or deteriorated insulation. This is labor-intensive work through finished walls.
Labor Estimating for Rewires
Rewiring finished construction is much slower than rough-in because you're drilling through walls, fishing wire through closed cavities, and often dealing with old plaster or difficult access. Expect to add 50-100% more labor compared to rough-in time:
- Simple 1,500 sq ft ranch with open walls: 40-50 hours
- Standard 2-story, 2,000 sq ft house: 60-80 hours
- Complex house with finished basements, lots of walls: 100+ hours
- Labor rate for rewire work: $75-$100/hour (more experienced, more complex)
Materials for a full rewire are similar to rough-in (wire, boxes, breakers, panel), but you might need additional fish tape, drywall repair supplies, and painting touch-up.
Adding Circuits and Outlets Estimating
Adding circuits to an existing panel or running new outlets is a smaller job but still requires careful estimating.
Labor and Material for New Circuits
- Adding a single new circuit (breaker installed, wire run to new outlet location): 3-5 hours for finished walls
- Multiple circuits in an addition (rough-in through open framing): 2-3 hours per circuit
- Kitchen circuit (20-amp dedicated, usually 12-gauge wire): 4-6 hours if running through walls
Material for a single new circuit: $80-$150 (wire, breaker, box, outlets). Labor at $75/hour × 4 hours = $300. Total: $380-$450 for a single circuit addition.
Common Electrical Estimating Mistakes
- Underestimating rewire labor — finished walls are 2-3x slower than open framing
- Forgetting code upgrades — AFCI, GFCI, bonding requirements can add $500-$1,500 to an upgrade
- Not confirming load calculation upfront — assuming 200-amp service is enough without calculating, then discovering it's not
- Underpricing service entrance work — the meter base, conduit, and grounding are often forgotten line items
- Mixing labor rates — journeyman vs. apprentice work has different rates; be clear on who's doing the work
- Not including permits and inspections — varies widely but can be $100-$400 depending on jurisdiction
Get Your Estimates Right Before You Bid
Electrical estimates have a lot of variables: service size, circuit count, wire runs, labor access, code requirements, and permit costs. If you're estimating by hand, you're likely missing line items or miscalculating labor time. Tools like BidFlow keep your estimates consistent and let you update labor rates and material costs quarterly so your bids stay accurate as the market changes.
Bottom Line
Electrical estimating requires three things: understanding load and service size, breaking down all the labor components (disconnect, installation, testing, final), and pricing materials correctly. Don't guess on labor time for rewires or retrofits — these jobs are slower than they seem. And don't forget permits and inspection fees; they're real costs. The electricians making money are the ones who estimate every line item and track actual labor time on each job to keep future bids accurate.