How to Estimate a General Contracting Job (Step by Step)

Start with the scope, not the number

A general contracting estimate is only as good as the scope behind it. Before you touch a calculator, walk the job with the customer and write down exactly what they want done, in plain language. Ask the questions that change the price: Who is pulling permits? Are there drawings, or are you working from a description? What finishes do they expect? When do they want it done?

Take photos and measurements on that visit. If drawings exist, do your own takeoff from them rather than trusting the square footage on the cover sheet. Every line item in your estimate will trace back to this scope document, and it becomes your defense later when the customer remembers the conversation differently.

Break the job into trades and phases

General contracting jobs fail as estimates when they get priced as one big blob. Split the job into the trades it actually involves: demolition, framing, plumbing, electrical, drywall, flooring, paint, and so on. Within each trade, list the tasks in the order they happen, because sequencing drives labor time and subcontractor scheduling.

This breakdown does two things for you. It shows you which parts your own crew handles and which parts go out for subcontractor bids, and it forces you to think through the whole job once before you are committed to a number. A trade you forgot to break out is a trade you just agreed to do for free.

Price your labor, subs, and materials

For work your own crew performs, price labor from your own production rates. You know from past jobs how long your crew takes to frame a wall or hang a door, so estimate hours per task and multiply by your loaded hourly cost, including payroll burden, not just wages. If you do not track production rates yet, start, because they are the foundation of every estimate you will ever write.

For subcontracted trades, get written bids, and make sure each sub is pricing the same scope you priced. A cheap bid that excludes disposal or patching is not cheap; it is a gap you will pay for. Compare bids line by line, and carry the real number, not the optimistic one.

Materials go in at your actual cost, including delivery and a realistic waste allowance. When prices move fast, note on the estimate that material pricing reflects current quotes and give the estimate a validity window.

• Own crew: task hours times your loaded hourly cost
• Subcontractors: written bids against your scope, compared line by line
• Materials: supplier quotes at real cost plus delivery and waste
• Equipment: rentals, delivery, and fuel as their own lines

Do not skip general conditions

General conditions are the costs of running the job that do not belong to any single trade, and they are where GC estimates most often come up short. They are real costs, so they belong in the estimate as real line items, not as an afterthought absorbed into your margin.

List them explicitly so the customer can see what it takes to run their project. This also separates them from your overhead and profit, which is your markup on top of all job costs and a business decision you make from your own numbers.

• Permits, plan review, and inspection fees
• Dumpsters, hauling, and disposal
• Temporary facilities, power, and protection of finished work
• Supervision and project management time
• Daily and final cleanup
• Small tools, consumables, and safety equipment

Where general contractors lose money

• Pricing from a phone call or the customer's description instead of a walk-through
• Accepting a sub's bid without checking it covers the same scope
• Treating general conditions as free because no single trade owns them
• Ignoring schedule risk: a job that drags burns supervision and overhead
• Quoting allowances that are lower than what the customer will actually pick
• Leaving exclusions unstated, so repair of hidden damage becomes your problem
• Forgetting to charge for change-order administration time

What goes on the estimate the customer sees

A customer-facing GC estimate should read like a contract in waiting: the scope in plain language, itemized costs by trade or phase, general conditions, allowances with their amounts stated, exclusions in writing, the payment schedule, and how long the price is valid. If you are new to structuring estimates, our guide on how to write an estimate covers the fundamentals every trade builds on.

You can draft this on site with an app like EstimateBook: describe the job by voice or attach photos, and it drafts itemized line items you can edit for quantities, prices, and markup before sharing a polished PDF. Whether you use an app or a spreadsheet, treat any draft as a starting point and check every line against your scope and your numbers before it goes to the customer.