Instant Trade & Construction Calculators
Fast, accurate, pro-grade calculators for contractors and DIYers.
Construction, Carpentry & Materials
Concrete Volume Calculator
Estimate cubic yards, cubic meters, and pre-mixed bag counts for slabs, driveways, and pads.
- Cubic yards & cubic meters output
- 60 lb and 80 lb bag count estimates
- Adjustable waste margin for spillage
Board Feet Calculator
Calculate board feet for hardwood, rough-sawn, and dimensional lumber takeoffs.
- Per-piece and total board feet output
- Multi-piece quantity with waste margin
- Rough-sawn thickness reference guide
Drywall Sheet & Screw Estimator
Calculate sheet counts for walls and ceilings with a full material breakdown for your drywall job.
- Sheet count by wall dimensions or total area
- Screws, joint tape, and ready-mix mud estimates
- Adjustable waste factor for cuts and breakage
Roofing Shingle Calculator
Estimate roofing squares and shingle bundles from footprint dimensions with pitch correction and waste margin.
- Pitch-adjusted surface area (2/12 to 12/12)
- Roofing squares and bundle count output
- Adjustable waste margin for cuts and breakage
Tile Spacing & Coverage Calculator
Estimate tile counts from room dimensions with grout joint spacing and adjustable waste margin.
- Square footage with grout matrix expansion
- Total tiles and optional box count
- Adjustable waste margin for layout patterns
Paint Coverage Calculator
Estimate gallons and quarts from room dimensions with door and window deductions and adjustable spread rate.
- Wall surface area with standard opening deductions
- Gallon and quart output with multi-coat math
- Adjustable coverage rate slider (200–450 sq ft/gal)
Insulation R-Value Calculator
Calculate achieved R-value from insulation thickness and find additional inches needed to hit code targets.
- Six material types — batt, blown-in, spray foam, rigid foam
- Target R-value slider from R-13 walls to R-60 ceilings
- Deficit thickness output when target is not met
Deck Joist Spacing Calculator
Estimate joist count, rim joist linear footage, and 16 ft board quantities for deck framing layouts.
- Joist count at 12", 16", or 24" on-center spacing
- Rim joist linear footage included in takeoff
- 16 ft board count with adjustable waste margin
Stair Stringer Calculator
Calculate riser count, total run, stringer length, and incline angle from total rise with IRC code compliance check.
- Riser count from target riser height
- Stringer hypotenuse and incline angle
- Live SVG stringer cut preview
Asphalt Driveway Cost Estimator
Estimate hot-mix asphalt tonnage, gravel subbase material, and total installed paving cost from driveway dimensions.
- Surface area and asphalt tonnage output
- Regional cost tiers from $7–$13/sq ft
- Gravel subbase tonnage takeoff
Rebar Quantity Calculator
Estimate rebar grid spacing, linear footage, and 20 ft stick counts for slabs, pads, and driveways.
- 20 ft rebar stick count with waste margin
- Total linear footage for grid layouts
- Grid intersection count for tie wire
Framing Lumber & Stud Count
Plan stud spacing, wall lengths, and lumber quantities for residential framing projects.
- Stud count by wall length and spacing
- Top and bottom plate linear footage
- Corner and opening adjustments
Excavation & Backfill Volume Calculator
Calculate bank, loose, and compacted cubic yards for excavation and backfill takeoffs with swell and shrink modeling.
- BCY, LCY, and CCY volume output
- Swell and shrink factor modeling
- Structural void deduction for foundations and utilities
Siding Material Estimator
Calculate siding squares from wall dimensions with opening deductions and adjustable waste factor.
- Opening count and average area deductions
- Adjustable waste factor for cuts and breakage
- Siding squares and retail box count output
Fence Post & Material Calculator
Calculate fence posts, picket infill, rail footage, and concrete bags for a straight fence run from length and spacing inputs.
- Post count via the plus-one end-cap rule
- Picket infill with custom width and gap spacing
- Concrete bag estimation per post hole
Concrete Block & Mortar Calculator
Estimate CMU block count, mortar bags, and optional core fill volume for hollow block walls from wall dimensions and waste factor.
- Block count with adjustable waste factor
- 80 lb mortar bag estimation (~11 blocks per bag)
- Optional core fill volume for grouted cells
Paver Calculator | Patio & Driveway Material Estimator
Accurately calculate pavers, base gravel, bedding sand, and polymeric sand for patios, walkways, and driveways. Smart warnings flag shallow base depth and high waste factors before you order.
- Paver count with base gravel and bedding sand in cu yd and tons
- Smart warnings for base depth and waste margin settings
- Polymeric sand and 50 lb bag estimates with waste allowance
Footing Concrete Calculator | Foundation Bag & Volume Estimator
Calculate concrete volume and bag counts for footings and foundations. Includes waste factor. Ideal for decks, houses, and structural concrete planning.
- Volume per footing, total cubic feet, and cubic yards
- 60 lb and 80 lb bag counts for ready-mix and DIY pours
- Multi-footing count with adjustable waste margin
Retaining Wall Block & Backfill Calculator
Estimate blocks, backfill gravel, and tonnage for retaining walls.
- Block count with adjustable waste margin
- Backfill volume in cu ft and cu yd
- Gravel tonnage from custom density
Plywood & OSB Sheathing Calculator
Estimate plywood or OSB panels for walls, roofs, and floors.
- Supports custom panel sizes
- Waste factor included
- Total coverage and panel count
Gravel & Aggregate Driveway Calculator
Estimate gravel volume, cubic yards, and tonnage for driveways.
- Cubic feet and cubic yards
- Tonnage from gravel density
- Waste factor included
Mulch & Landscape Bed Calculator
Estimate mulch volume, cubic yards, and weight for landscape beds.
- Cubic feet and cubic yards
- Weight in pounds and tons
- Waste factor included
Gutter & Downspout Length Calculator
Estimate gutter length, downspout height, and total linear footage.
- Gutter + downspout length
- Waste factor included
- Supports custom allowances
Electrical & Wiring
Wire Gauge (AWG) Calculator | Electrical Load & Voltage Drop Estimator
Determine the correct wire gauge based on amperage, circuit length, voltage, and allowable voltage drop.
- AWG gauge recommendation
- Voltage drop calculation
- Copper & aluminum support
- 120V and 240V circuits
- Code-safe wire sizing
Voltage Drop Calculator | Electrical Wire Loss & Efficiency Estimator
Calculate voltage drop and voltage drop percentage for copper or aluminum electrical circuits.
- Voltage drop calculation
- Voltage drop percentage
- Copper & aluminum support
- Full AWG gauge selection
- 120V and 240V circuits
Breaker Size Calculator | NEC 80% Rule Electrical Load Estimator
Determine the correct circuit breaker size using NEC continuous load rules.
- NEC 80% continuous load rule
- Standard breaker size selection
- 120V and 240V support
- Safety warnings for high loads
- Electrical panel compatibility guidance
Conduit Fill Calculator | NEC Chapter 9 PASS/FAIL Estimator
Calculate conduit fill percentage and determine NEC compliance using conductor count, wire gauge, and conduit size.
- NEC 40% fill rule
- PASS/FAIL compliance indicator
- Supports EMT, PVC, and FMC
- Full AWG gauge selection
- Copper & aluminum conductor support
Generator Sizing Calculator | Running & Surge Watt Load Estimator
Calculate the correct generator size based on running watts, surge watts, voltage, and NEC continuous load rules.
- Running & surge watt calculation
- NEC 125% continuous load rule
- 120V and 240V support
- Safety warnings for large generators
- Transfer switch compatibility guidance
Load Calculation Tool | Electrical Panel Sizing Calculator
Calculate total electrical load and determine the correct service panel size using NEC continuous load rules.
- NEC 125% continuous load rule
- Total wattage and amperage calculation
- Recommended panel size
- PASS/FAIL compliance check
- Supports 120V and 240V systems
Motor Full Load Amps (FLA) Calculator | Electrical Motor Load Estimator
Calculate motor full-load amperage (FLA) based on horsepower, voltage, phase, efficiency, and power factor.
- Single-phase and three-phase support
- Efficiency and power factor adjustments
- Accurate FLA calculation
- Motor load safety warnings
- Supports 120V, 208V, 240V, and 480V motors
Lighting Foot-Candle Calculator | Lumens & Illumination Estimator
Calculate foot-candles based on lumens, fixture count, and area size.
- Foot-candle calculation
- Lumens to FC conversion
- PASS/FAIL lighting compliance
- Supports any fixture type
- Commercial & residential lighting
Transformer Sizing Calculator | kVA Load Estimator
Calculate transformer kVA requirements based on load amps, voltage, phase, and NEC continuous load rules.
- Single-phase & three-phase support
- NEC 125% continuous load rule
- kVA calculation
- PASS/FAIL transformer sizing
- Supports 120V, 208V, 240V, 277V, 480V
Electrical Resistance Calculator | Ohm's Law & Resistivity
Calculate electrical resistance using voltage/current or resistivity, length, and conductor area.
- Ohm's Law resistance calculation
- Resistivity-based resistance
- Supports conductor length & area
- Material resistivity input
- Dual-mode calculation
Solar Panel & Inverter Sizing Estimator | PV System Calculator
Estimate solar array wattage, number of panels, and inverter size based on energy usage and sun hours.
- Solar array sizing
- Inverter sizing
- System loss adjustment
- PASS/FAIL inverter check
- Supports any panel wattage
EV Charger Circuit & Load Calculator | Breaker & Panel Sizing
Calculate EV charger load, breaker size, wire gauge, and panel impact using NEC continuous load rules.
- EV charger load calculation
- Breaker sizing
- Wire gauge recommendation
- Panel load impact
- PASS/FAIL compliance
Three-Phase Power & Cost Estimator | kW, kVA & Energy Cost Calculator
Estimate three-phase power, energy usage, and cost based on voltage, current, and power factor.
- Three-phase kVA calculation
- Real & reactive power
- Energy cost estimation
- Service capacity PASS/FAIL
- Supports 208V, 240V, 480V systems
Box Fill Calculator (NEC 314) | Electrical Box Volume Estimator
Calculate NEC-compliant box fill volume based on conductor count, devices, clamps, and wire gauge.
- NEC Article 314 compliant
- Conductor volume calculation
- Device & clamp volume rules
- PASS/FAIL box size check
- Supports 14–6 AWG
Generator Transfer Switch Interlock Planner | NEC 702 Load & Breaker Estimator
Plan generator interlock configurations, breaker sizing, and essential load compatibility using NEC guidelines.
- Generator load calculation
- Interlock breaker sizing
- Essential load PASS/FAIL
- Main breaker compatibility
- Manual vs automatic transfer