Contractor & trades · 27 calculators
Contractor and trades calculators
Material quantities, markup pricing, bond costs, workers comp estimates, and job-costing math for contractors who need the number before the bid goes out.
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Gravel & fill cubic yards calculator
Cubic yards of gravel, crushed stone, fill dirt, or sand for any excavation or landscaping project.
Drywall sheets calculator
Sheets of drywall for rooms or full jobs — wall area, ceiling option, door/window deductions, and 10% waste.
Paint coverage calculator
Gallons of paint for any room or surface — coverage rate, number of coats, doors, windows, and waste.
Tile square footage calculator
Tile quantity with configurable waste factor for floors, walls, showers — accounts for diagonal cuts and grout joints.
Roofing materials calculator
Roofing squares, underlayment rolls, starter strip, ridge cap, and hip/valley flashing from roof dimensions.
Carpet square yards calculator
Square yards of carpet from room dimensions — seam allowance, waste percentage, and pad quantity.
General liability premium estimator
Ballpark GL insurance premium from trade type, annual revenue, and payroll using ISO rate-per-$1,000 factors.
Wallpaper rolls calculator
Rolls of wallpaper from room dimensions and roll coverage — with pattern repeat waste and door/window deductions.
Electrical conduit fill calculator
Maximum wires in conduit by type and size using NEC 2023 Chapter 9 fill tables — EMT, PVC, and flexible conduit.
Equipment depreciation calculator
Annual depreciation under MACRS, straight-line, and Section 179 expensing — with year-by-year schedule and tax impact.
Concrete driveway bid calculator
Build a defensible concrete driveway bid — material yards, labor crew-hours, demolition, rebar/mesh, formwork, finishing, and a target margin. Skip the spreadsheet guesswork.
Roofing bid cost calculator
Estimate materials + labor + dump fees for an asphalt-shingle reroof. Squares-based estimate that mirrors how real roofers price.
Exterior paint coverage calculator
Calculate paint gallons and total project cost for an exterior repaint, accounting for coats, surface texture, and primer.
Residential electrical load calculator
Estimate total amperage demand using NEC standard load calculation method to size a residential service panel (100A vs 200A).
HVAC tonnage sizing calculator
Manual J shortcut: estimate AC tonnage and BTU requirement for a residential space based on square footage, climate, insulation, and orientation.
Fence installation cost calculator
Estimate total cost of a residential fence install: posts, panels/pickets, gates, hardware, concrete, and labor.
Deck lumber takeoff calculator
Calculate joist count, board feet of decking, and total lumber cost for a residential deck build.
Gravel driveway cubic yards calculator
Calculate cubic yards of gravel needed for a driveway or pad and total delivered material cost.
Retaining wall block count calculator
Calculate block count, base gravel, drainage stone, and total cost for a segmental retaining wall (SRW) install.
Plumbing rough-in cost calculator
Estimate plumbing rough-in cost for a residential remodel or new build, priced by fixture count plus permit and water-heater carve-outs.
Asphalt driveway cost calculator
Estimate full installed cost of a residential asphalt driveway including subbase, paving, sealing, and removal of existing surface.
FAQ
contractor & trades questions, answered
Q1.What markup should I add on subcontractor work?
Industry-standard GC markup on subs is 10-20% — covers your overhead, supervision, warranty exposure, and profit. The calculator runs the full job cost including subs, your direct labor + materials, and the blended markup needed to hit a target margin. Below 10% is usually a red flag (you're absorbing risk you're not pricing for); above 20% is workable in specialty trades but makes you uncompetitive in standard residential.
Q2.How is workers comp premium estimated?
Premium = payroll / 100 × class code rate × experience modifier. The calculator handles class-code rates (NCCI codes), state ratemaking variance, and the experience mod (which compounds — a 0.85 mod saves you 15% per year forever). Run it before you set crew size; misclassified or under-priced WC is one of the top three small-contractor margin leaks.
Q3.When do I need a performance bond and what does it cost?
Public projects above $100k typically require performance + payment bonds; many private commercial projects request them above $500k-1M. Cost is 0.5-3% of contract value, scaled by your credit profile, financial statements, and bonding history. The calculator runs the premium and shows the impact on your bid — which is what most subcontractors miss when they're bidding their first bonded job.
Q4.How does the job cost per square foot calculator work?
It splits the job into materials, labor, equipment, overhead, and profit, then divides by total square footage. The output is your true cost per sf — distinct from the regional 'average cost' numbers that don't account for your overhead, your crew speed, or your specific material spec. This is the number you use to detect under-bidding before you sign — if your cost per sf is materially below regional medians, you're either better than them or about to lose money.
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