Free tools
Construction estimating calculators for contractors
Five trade calculators with the standard formulas, every assumption editable and your own unit costs. Use them for budgets, checks and small scopes, then send the plans when you need a measured takeoff.
Fixed price in 2 business hours. Pay only after you accept.
- Free to use, nothing stored
- Standard formulas, shown on each page
- Every default assumption is editable
- Your unit costs, not a borrowed average
Quick answer
Bidmere’s construction estimating calculators are free tools for painting, drywall, concrete, roofing, insulation, demolition, rebar, CMU block, stud framing and asphalt, plus a contractor markup calculator. Each one shows the formula, lets you edit every assumption, and prices quantities with unit costs you enter. For a bid on a full plan set, Bidmere prepares measured trade estimates from $195, ready in 48 hours.
Which construction estimating calculators are available?
There are eleven calculators: quantity calculators by trade and a markup calculator for pricing the bid. Each one runs in your browser, updates as you type and copies the full breakdown to your clipboard.
- Painting estimate calculator: Paintable area, gallons by coat and spread rate, labor hours and painting cost per square foot.
- Drywall calculator: Board area by sides and layers, sheets by size, finishing materials and drywall cost per square foot.
- Concrete calculator: Cubic yards for slabs, footings and piers, with waste, order rounding and concrete cost per square foot.
- Roofing estimate calculator: Roof squares by pitch, bundles or membrane rolls, edges and ridges, and cost per square.
- Insulation calculator: Bags, boards or spray foam sets from your product’s coverage, R-value and insulation cost per square foot.
- Contractor markup calculator: Bid price from overhead and profit, markup vs margin both ways, and your own overhead rate.
- Demolition cost calculator: Debris tons from area, haul loads and demolition cost per square foot at your rates.
- Rebar calculator: Bars, linear feet, pounds and tons for slab grids, footings and walls, with laps.
- CMU block calculator: Blocks, mortar bags and grout fill by wall size, openings and grouted cell spacing.
- Stud framing calculator: Wood or metal studs by spacing, plates or track, and extra studs at openings and corners.
- Asphalt calculator: Asphalt tonnage from area, thickness and mix weight, plus a sealcoat gallons mode.
Every calculator has a worked fictional example, the formula in a table, and a list of the commercial scope it does not cover. Those lists are where most calculator-based bids go wrong.
How these contractor calculators work
Each calculator follows the same pattern: measure, convert to purchase units, add waste, then price. Nothing is hidden in a default you cannot see.
- Measure. You enter dimensions in the units the trade uses: lineal feet, square feet, inches of thickness, pitch.
- Convert. The tool turns area or volume into what you order: gallons, sheets, cubic yards, squares, bags, boards or sets.
- Add waste. Waste is a percentage you control. It starts at a common value for the trade.
- Round to purchase units. You cannot buy 12.5 gallons or 23.3 sheets, so results round up.
- Price. You enter your own material prices, labor rates and lump sums. The tool reports a total and a cost per square foot, per square, per cubic yard or per lineal foot.
Defaults that come from a manufacturer, such as paint spread rate, bag yield for concrete mix or batt coverage per bag, are labeled with their source on the tool page. Replace them with the product you are pricing.
Why our calculators do not show a national cost per square foot
A cost per square foot is only useful if it is your cost. Published averages mix regions, building types, union and open shop labor, and years.
We do not put a market cost per square foot into these tools because we could not source one that fits every job. Instead, each calculator divides your total by the right base: paintable area for painting, board area for drywall, slab area for concrete, roof surface for roofing and area insulated for insulation. That gives a number you can compare against your past jobs and defend in a bid review.
If you want the drivers behind cost per square foot for a whole building, see the construction cost per square foot guide.
Construction estimating units these calculators use
Every trade has its own pricing unit. Mixing them up is a common estimating error, so here are the units and conversions the tools use.
| Unit | Meaning | Used for |
|---|---|---|
| SF | Square foot | Wall, ceiling, slab, board and insulation area |
| LF | Lineal foot | Wall length, footing length, trim, drip edge, ridges |
| CY | Cubic yard, 27 cubic feet | Ready-mix concrete |
| SQ | Roofing square, 100 SF of roof surface | Shingles, membrane, roofing labor |
| BF | Board foot, 1 SF at 1 in thick | Spray foam and rigid board |
| EA | Each | Doors, sheets, boards, piers, drains |
| gal | US gallon | Paint and primer |
Two conversions come up all the time. Inches of thickness divide by 12 to get feet. Cubic feet divide by 27 to get cubic yards.
Calculator, takeoff or estimate: which do you need?
A calculator is enough for one area and one product. A bid on a plan set needs a takeoff, and a bid number needs an estimate.
| Calculator | Takeoff | Estimate | |
|---|---|---|---|
| Input | Dimensions you type | Plans and specifications | Takeoff plus your rates |
| Output | Quantities for one area | Every quantity by item, sheet and revision | Priced quantities, assumptions, exclusions |
| Catches plan conflicts | No | Yes | Yes |
| Good for | Budgets, checks, small jobs | Pricing in your own system | Bids and proposals |
Read more in estimate vs takeoff vs bid and what a takeoff includes.
Need the whole job measured? A calculator covers one room or one pour. Send the plans and we return the full takeoff and estimate. Fixed quote within 2 business hours. Plan review is free, and you pay only after you accept.
Get a fixed quoteCan homeowners use these calculators?
Yes. The formulas are the same for a house and a commercial building. A homeowner can use the painting, drywall, concrete, roofing or insulation calculator to check a contractor’s quantities or plan a project.
Two cautions. First, enter real local prices; the tools do not supply them. Second, a contractor’s price includes overhead, insurance, warranty and profit, so it will be higher than materials plus hourly labor. Bidmere works for contractors, not homeowners, and prepares estimates only from plans.
When to send the plans instead
Send the plans when you are bidding a commercial job and the scope runs past one area and one product. That is when missed doors, wall types, flashing details or rebar cost real money.
Bidmere prepares trade takeoffs and estimates from your plans and specifications. We measure every quantity, tie it to the sheet and revision, and price it with the rates you approve. Assumptions, exclusions and open questions are written out. Plan review is free. You get a fixed quote within 2 business hours and pay only after you accept the price and delivery date. Single-trade estimates are from $195 and ready in 48 hours; multi-trade estimates are from $1,150. You get an Excel estimate with live formulas, color-coded marked-up PDF plans, and a written list of assumptions, exclusions and open questions.
Before you send plans
Common questions about handing off the work
Are these calculators accurate enough to bid?
The formulas are standard. The quantities are only as good as the dimensions and assumptions you enter, and they skip scope a plan takeoff catches.
Will Bidmere take over my estimating?
No. We measure and price with your rates. You set markup, sign and submit.
What happens to the numbers I type?
Nothing leaves your browser. Copy the results if you want to keep them.
Monthly estimating plans
Bid every week? Ask about monthly estimating plans
If your team bids every week, a monthly plan can cost less per bid than ordering one at a time. Plans run $1,395 per month for up to 6 bids, $2,595 per month for up to 12 bids or $4,795 per month for up to 25 bids. Each bid gets the same measured takeoff, your rates and written assumptions. See outsourced estimating.
Questions
Frequently asked questions
Are the Bidmere construction calculators free?
Yes. All the calculators are free, need no sign-up and run in your browser. They do not send or store anything you type. Use the copy results button on each tool to paste the breakdown into your estimate, a spreadsheet or an email. Bidmere charges only for estimating and bid preparation work you accept.
Which formulas do the calculators use?
Standard trade formulas, shown on each tool page. Paint gallons are area times coats divided by spread rate. Drywall sheets are board area divided by sheet area. Concrete cubic yards are length times width times thickness in feet, divided by 27. Roofing squares are plan area times the pitch multiplier, divided by 100. Insulation units are area divided by coverage per unit. Waste is added to each.
Why do I have to enter my own unit costs?
Because costs change by market, supplier, crew and season, and no single sourced figure fits every job. A borrowed average can make a bid too high to win or too low to make money. With your own prices, the cost per square foot the calculator reports matches how you actually build.
Can I use a calculator instead of a takeoff for a commercial bid?
For a small, simple scope, maybe. For a full plan set, no. A calculator measures one area with one product. A takeoff measures every item on every sheet, ties it to the revision, and catches conflicts between plans, schedules and specifications. Each calculator page lists the commercial scope it leaves out.
Will you add calculators for other trades?
We plan to add more trades over time. If you need a quantity for a trade we do not cover yet, send the plans and ask for a quote. Bidmere prepares takeoffs and estimates across commercial trades, priced at your rates, with a fixed quote in 2 business hours and free plan review.
How much does a Bidmere trade estimate cost?
Single-trade estimates are from $195 and ready in 48 hours after you accept a fixed quote. Multi-trade estimates are from $1,150. Takeoff-only work is from $149. Plan review is free, the quote arrives within 2 business hours, and you pay only after you accept the price and delivery date.
Get a fixed quote
Share the project basics. You get a fixed price and delivery date within 2 business hours. Plan review is free, and you pay only after you accept.