How to Estimate a Construction Project, Step by Step

To estimate a construction project, read the whole plan set, specs, and addenda, take off every quantity, price materials, labor, equipment, and subcontractors, then add general conditions, overhead, profit, insurance, and contingency. Finish by listing your alternates, exclusions, and open questions, and check the total before you send it. The steps below follow the order a careful estimator works in.

Read the whole set before you measure anything

Open everything: the drawings, the specifications, every addendum, and any survey or soils report in the bid package. Specs often override what a plan note says, and the general notes sheet is where scope hides. A line like "contractor to provide temporary shoring" is easy to miss if you go straight to the floor plans.

Write down the bid due date, the RFI cutoff, and any pre-bid walk before you do anything else. Then build a scope sheet. List every trade, and mark each one as yours, a subcontractor's, the owner's, or not shown. Gaps in this list become the surprises in the field.

If you can, walk the site. Existing conditions, access for deliveries, overhead lines, and where the dumpster can sit all change labor and general conditions, and none of them are on the drawings. Take photos and notes while you are there, and keep them with the estimate.

Take off quantities by CSI division

Organize the takeoff by CSI MasterFormat division, the same way the specifications are organized. It matches how subcontractors quote, and it makes a missing scope obvious because a division with no numbers stands out.

• Division 03: Concrete
• Division 04: Masonry
• Division 05: Metals
• Division 06: Wood, plastics, and composites
• Division 07: Thermal and moisture protection
• Division 08: Openings (doors and windows)
• Division 09: Finishes
• Divisions 22, 23, 26: Plumbing, HVAC, and electrical
• Divisions 31 and 32: Earthwork and exterior improvements

Every takeoff line needs an item, a unit, a quantity, and the sheet the number came from. Measure from the best sheet for the job: floor plans for counts and lengths, sections and elevations for heights, and details for sizes. Work in a fixed order, such as floor by floor or system by system, and mark each item on the plans as you count it. That one habit prevents most double counts and most skipped rooms. If you are new to this step, start with what a takeoff is and how it works.

Price materials, labor, equipment, and subcontractors

With quantities in hand, price each cost type separately. Mixing them is how mistakes get buried.

Materials

Get quotes from at least three suppliers on the big items and compare them on the same terms: same spec, same quantity, delivered or picked up. Apply the sales tax for the job's location, add delivery, and note when each quote expires. Keep waste on its own line.

Labor

Labor is the quantity times the hours per unit times a burdened hourly wage. Hours per unit come from your own job history or a published labor-unit source. Wages should be local, and the BLS Occupational Employment and Wage Statistics program publishes pay by occupation and area.

Burden is everything you pay on top of the wage: payroll taxes, workers' comp, insurance, and benefits. For scale, the Bureau of Labor Statistics reported that benefits were 30.0 percent of total employer compensation for private industry workers in June 2026. That works out to a burdened hour about 43 percent above the wage on average. Your own figure depends on your workers' comp class codes and benefits, so take it from your payroll records.

Then adjust the hours for conditions the job implies: a second-story install, a tight site, working in an occupied home, or a repeated detail that speeds up the crew. Write the adjustment down so the next person knows why the hours moved.

Equipment

Include rentals, delivery and pickup, fuel, and mobilization. For equipment you own, use an hourly rate that covers ownership and upkeep. Lifts, cranes, and compaction equipment are common misses on small jobs.

Subcontractors

Get at least two or three quotes for each major trade and compare them line by line, not by the bottom number. Check what each one excludes: permits, patching, hauling, cleanup, or temporary power. If a quote has not come in by the deadline, carry an allowance and label it clearly as one.

Sub quotes tend to arrive close to the deadline, so leave time to level them. Make sure two quotes cover the same scope, and look for work that falls between trades, such as who patches after the electrician or who sets the plumbing fixtures.

Add general conditions and markups

General conditions are the costs of running this job that do not belong to a single trade: supervision, permits and fees, dumpsters, temporary fencing and toilets, protection of finished work, and final cleaning.

After that come the markups, each on its own line so you can see and change them:

1. Overhead: the cost of running your company, such as office, software, vehicles, and your own time.
2. Profit: what you are in business to earn.
3. Insurance and bonding: job-specific premiums that are not already in your overhead.
4. Contingency: an allowance for unknowns, sized to how complete the drawings are.

Here is a small example. Every number is made up to show the math, so do not copy the rates.

Here each markup is a percent of the $65,000 subtotal. Some contractors compound them instead. Either way works, as long as you pick one method and show it on the sheet.

List alternates, exclusions, and RFIs

A bid is only as good as the questions it admits to. Three lists protect you.

Alternates are priced options the bid documents ask for, shown as an add or a deduct, such as an upgraded floor finish. Exclusions are the things your price does not cover, such as permits, hazardous material removal, or owner-supplied items. RFIs and clarifications are the questions the drawings do not answer, each with the assumption you used while you wait.

For example, if the laundry room has no floor finish noted, write "Sheet A-4 shows no laundry finish; priced vinyl plank; please confirm." That one line turns a hidden risk into a documented decision.

Check the estimate, then present the bid

Before the number leaves your office, run these checks.

1. Look for empty divisions. Every division should have a number or a stated exclusion.
2. Compare cost per square foot with similar past jobs. A large gap is a reason to look again.
3. Confirm every addendum is acknowledged and priced.
4. Re-add the math. A single wrong sum cell can move a bid by thousands.
5. Have someone else read it. A second reviewer finds what the first one has stopped seeing.

Then present the bid on a clean summary: the price, the scope included, the exclusions, alternates, key assumptions, schedule, how long the price is good for, and payment terms. Keep the detailed worksheet behind it. If the price is only good for a limited time, say so. Material prices move, and a bid with no expiration date is an open offer. If the job is electrical heavy, our guide to electrical estimating shows how that trade is broken down.

Where BidMe fits

BidMe does this work for contractors who would rather not do it at night. Labor is priced as hours per unit times the local wage from public wage data such as BLS, with burden. Materials are compared across several suppliers, local sales tax is applied, and overhead, profit, insurance, and contingency appear as their own lines that you can change. Anything the drawings do not settle is listed as an RFI. You can read about residential estimating or commercial estimating, and pricing starts at $200 per residential project and $400 per commercial project.