Free Construction & Trade Calculators
Estimate materials.
Save money.
Build right.
Fast, accurate calculators for construction, electrical, landscaping, and surface projects — built on DOT and NEC reference data.
45
Free Calculators
4
Trade Categories
NEC
NEC Tables
DOT
Reference Data
Browse by Category
16 Calculators
Construction
Concrete, asphalt, gravel, sand, pavers, brick, drywall, siding, and roofing tools.
9 Calculators
Electrical
Conduit fill, wire sizing, voltage drop, load calculation, and reference tools.
6 Calculators
Landscaping
Mulch, topsoil, compost, sod, lawn seed, and yard material estimates.
14 Calculators
Surface
Paint, flooring, tile, and stain coverage calculators.
Most Popular
Construction
Concrete Slab Calculator
Cubic yards and bags for slabs by thickness
Construction
Asphalt Calculator
Tons of hot-mix for driveways and lots
Electrical
Conduit Fill Calculator
Fill % and pass/fail against reference limits
Electrical
Voltage Drop Calculator
Drop % by length, wire, and load
Landscaping
Mulch Calculator
Yards and bags for beds and paths
Landscaping
Topsoil Calculator
Tons and yards for lawns and grading
Surface
Paint Calculator
Gallons needed by area and coverage
Surface
Tile Calculator
Tiles and boxes by tile size and area
Why CalcShed
Reference-First Data
Calculations are built from published tables and standard unit conversions. We cite assumptions and show formulas instead of hand-waving.
Built for Mobile
Fast inputs, clear outputs, and no external libraries. The calculators are designed to work well on-site, not just on a desktop.
Transparent Methodology
We document formulas and assumptions so you can sanity-check results. See our Methodology and Data Sources pages for the details.