Electrical estimating: the whole process, from plans to bid

What is electrical estimating?

An electrical estimate answers one question: what will it cost this company to install this scope, and what price should it bid? Everything else is detail. The estimator reads the documents, counts and measures what is drawn, prices the material, works out the labor hours, adds the costs of running the job, and puts a margin on top. On commercial work the estimate usually goes to a general contractor as a subcontract bid; on some public and design-build work it goes straight to an owner.

This guide is electrical estimating 101 for commercial work, written for estimators and for owners of electrical contracting firms who do their own takeoffs. If you are picking tools, the electrical estimating software guide compares the main programs. If you want the bidding side (finding work, go or no-go, bid day), read how to bid electrical jobs.

1. Review the bid documents

Start with the specifications, not the drawings. On commercial projects organized by CSI MasterFormat, electrical work sits in Division 26 (Electrical), communications in Division 27 and electronic safety and security in Division 28. CSI released MasterFormat 2026 with title clarifications in Division 26 and noticeable expansion in Division 28, so check which edition the project manual uses.⁴ Division 01 matters too: it is where allowances, alternates, unit prices and closeout requirements live.

Then the drawings: the sheet index, the legend and general notes, the one-line diagram, panel schedules, the fixture schedule, and every power, lighting and systems plan. Read the mechanical and plumbing sheets for equipment you have to connect, and the architectural sheets for ceiling types and wall construction, which drive labor. Last, the addenda: list each one by number and date, mark what it changed, and make sure the bid form acknowledges all of them. A missed addendum is one of the cheapest mistakes to prevent and one of the most expensive to make.

2. Write the scope and exclusions

Before counting, write down what you are pricing. A scope sheet organized by spec section, with three columns (included, excluded, by others), keeps the estimate honest and becomes the backbone of your proposal. The usual gray areas on commercial work are fire alarm, low voltage cabling, security, utility company charges, temporary power, trenching and concrete for site lighting, mechanical control wiring, and owner-furnished equipment. On renovations add demolition, make-safe work and work in occupied areas. Each one is either in your number or written as an exclusion; there is no third option that holds up after award. If fire alarm and low voltage are yours, the low voltage estimating guide covers how those scopes are taken off, and the electrical bid template has a ready exclusions list. On a new service, size it with the electrical load calculation worksheet before you price gear.

3. Do the electrical takeoff

The electrical takeoff is the list of quantities: devices, fixtures and gear counted by type, and conduit, wire and cable measured by length or built up from assemblies. Count per sheet and per area if the bid breaks out by building, floor or phase. The takeoff is usually the longest single task in the estimate, which is why most shops now do it on screen. The electrical takeoff software guide explains the four ways software counts a plan set, and the electrical takeoff sheet is a free template if you work in a spreadsheet.

4. Price the material

Material pricing comes from two places. Gear, the lighting package and specialty systems are quoted by suppliers for the specific job, and those quotes often arrive on bid day. Commodity items (wire, conduit, fittings, boxes, devices) are priced from a price file kept current by a pricing service or by your distributor. Trimble's TRA-SER is one such service: its electrical plan lists at $1,260 per user per year for the US and Canada and includes Supplier Xchange for pulling prices from your suppliers.⁵

Read every quote for what it leaves out: freight, startup, spare parts, lamps, controls, and above all lead time. In the AGC's 2026 outlook survey, contractors named electrical equipment (switchgear, transformers, generators, control systems) as the most frequently mentioned supply chain problem, with many items still long-lead, and 40% of firms said they had raised bid prices in response to tariffs.⁶ If a quote is only good for 30 days and the gear will be bought in six months, the estimate needs an escalation line or a qualification.

5. Apply labor units

A labor unit is the number of hours one worker needs to install one unit of an item: one receptacle, one fixture, 100 feet of conduit. Multiply each quantity by its unit and you have the job's direct labor hours. Most commercial electrical estimating software ships with a labor database, and many shops start from the NECA Manual of Labor Units, then adjust with their own job history.

The NECA manual gives three columns per item: Normal, Difficult and Very Difficult. Its Labor Factor Score Sheet scores each job condition from 1 (normal) to 5 (most difficult) and picks the column from the total: 36 to 75 points for Normal, 76 to 134 for Difficult, 135 to 150 for Very Difficult. Above 150, NECA says the Very Difficult column may be inadequate and points to ELECTRI International studies and the contractor's own experience.⁷ The conditions on the sheet are a good checklist on their own: working height, building height, new construction versus remodel or work while occupied, type of construction, hours and shifts, crew density, schedule compression, conduit type, accessibility, drawing completeness and change order timing, among others.

Whatever book you start from, the best labor units are the ones you have checked against your own completed jobs. Compare estimated hours with actual hours by system at closeout, and adjust.

6. Set the labor rate

Labor hours become dollars through a composite rate: the average cost per hour of the crew you will actually run, foreman, journeymen and apprentices together, including payroll taxes, insurance and fringe benefits. Two public numbers show why the burden matters. The median electrician earned $30.38 an hour in May 2025², and across the construction industry wages were 69.5% of total compensation in June 2026, with benefits the other 30.5%.³ Union shops build the rate from the local agreement; open shops from their own payroll. Either way, use the rate for this job and this crew mix, not a company average.

Composite rate = (sum of each worker's hourly wage + burden + fringes) / number of workers in the crew

7. Add job costs and general conditions

Job costs are what the project needs that is not an installed item. List them line by line instead of hiding them in a percentage, because they depend on duration and conditions, not on the size of the material list.

• Supervision and project management for the length of the job
• Lifts, scaffolding, trenching equipment and other rentals
• Permits, inspections and utility fees
• Temporary power and lighting, when it is yours
• Trucks, job trailer, storage, small tools and consumables
• Testing, commissioning support, training, as-builts and O&M manuals
• Bonds and project-specific insurance
• Escalation on long-lead gear and multi-year schedules

8. Add overhead and profit

Overhead is the cost of the company: office, estimating, accounting, insurance not charged to jobs. Profit is the return. Decide whether you work with markup (a percentage added to cost) or margin (a percentage of the selling price), because the same number gives different prices. A 15% markup on $100,000 is $115,000; a 15% margin is $117,647.

Selling price = total cost / (1 - target margin)

9. Review the bid

Before the number goes out, check it from a direction you did not use to build it. Compare dollars per square foot with similar past jobs (the electrical cost per square foot guide shows how to build that history), compare labor hours per device and the material to labor ratio, and look hard at the ten biggest lines. Then reread the exclusions against the specs. A second person reviewing the summary catches more than a third pass by the estimator.

Electrical estimating methods

There are three common electrical estimating methods, and most shops use all three at different stages. Gordian, which publishes RSMeans data, puts a square foot estimate at roughly 20% of final cost, a systems and assemblies estimate within 10 to 15%, and a unit price estimate within 10%.⁸ Those figures describe whole-building estimates, but the order holds for the electrical scope too.

A common mix: assemblies for branch devices and fixtures, detailed pricing for gear and feeders, and dollars per square foot only as a check at the end.

A worked example: one line of an estimate

The numbers below are made up to show the arithmetic. They are not market prices or published labor units; use your own price file, your own labor units and your own rate.

Every other line works the same way. Job costs, overhead and profit are added once, on the total, not line by line. The electrical estimate template lays out the full summary, and the electrical estimate calculator runs the math in the browser.

Where AmpCount fits

AmpCount handles one part of step 3: the device and fixture count. It reads the legend on a vector PDF set, counts every symbol type on every sheet, keeps uncertain marks out of the count until you confirm them, checks fixtures against the schedule, and exports quantities per drawing with your item codes for your estimating software. It does not price material, apply labor units, measure conduit or size wire. Those stay in your estimating program and your judgment. To learn the rest of the craft, see electrical estimating classes.

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