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.
59
Free Calculators
5
Trade Categories
NEC
Code Tables
DOT
Reference Data
CalcShed is a free library of 59+ construction and trade calculators for concrete, electrical, landscaping, and surface materials, plus home improvement cost estimates. Every calculator shows its formula and source standards (ACI, NEC, ASTM, DOT data) so you can verify the math, not just take a number.
Browse by Category
24 Calculators
Construction
Concrete, roofing, asphalt, gravel, pavers, brick, lumber, and framing tools.
11 Calculators
Electrical
Conduit fill, wire sizing, voltage drop, load calculation, and reference tools.
9 Calculators
Landscaping
Mulch, topsoil, compost, sod, seed, decorative stone, and yard materials.
9 Calculators
Surface
Paint, flooring, tile, siding, drywall, stain, and wallpaper calculators.
6 Calculators
Home Improvement Costs
Roofing, solar, HVAC, window, and remodeling project cost estimates with local quotes.
Most Popular
Construction
Roof Truss Calculator
Truss length and count by span and pitch
Construction
Concrete Bag Calculator
60/80 lb bags for a target volume
Surface
Stain Calculator
Stain gallons by wood surface area
Surface
Flooring Calculator
Boxes needed by area and waste
Construction
Brick Calculator
Brick count and mortar by wall area
Construction
Roof Area Calculator
Roof area from footprint and pitch
Construction
Sand Calculator
Sand tons and yards for fill and bedding
Construction
Concrete Slab Calculator
Cubic yards and bags for slabs
Construction
Asphalt Calculator
Tons of hot-mix by area and depth
Project Cost Estimators
View all
Cost
Roof Replacement Cost Calculator
Estimate installed roof replacement cost by area, material, and region.
Cost
Window Replacement Cost Calculator
Estimate installed window replacement cost by count, material, and region.
Cost
Fence Cost Calculator
Estimate fence installation cost by length, material, and height.
Cost
Drywall Cost Calculator
Estimate installed drywall cost by area, board type, finish level, and region.
Cost
Subfloor Cost Calculator
Estimate subfloor replacement and installation cost by room size, material, and region.
Cost
Framing Cost Calculator
Estimate the cost to frame a house by floor area, structure type, scope, and region.
What's New at CalcShed
Every calculator lists its sources - here is what we have shipped and corrected lately.Panel counts by coverage width (36, 24, 16, and 12 inch profiles), cut length with overhang, and fastener counts - not just squares.
Wire sizing now applies the NEC 240.4(D) small-conductor limits and a 60 C column for NM-B cable. Every ampacity value re-verified against NEC 310.16.
Gate widths now come out of the picket and rail run, and the tool returns post length and hole depth - the two most common over-order mistakes.
Crushed stone, river rock, and mulch densities corrected to supplier-quoted values with sources shown - several were over-ordering by 30 to 50 percent.
Every calculator now has a free embeddable widget with light and dark modes that resizes itself to fit your page.
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.