3 new electrical calculators added
New tools cover transformer calculations, kVA-to-amps conversion, and power factor calculations for common single-phase and three-phase workflows.
Free Construction & Trade Calculators
Estimate materials.
Save money.
Build right.
Fast, practical calculators for construction, electrical, landscaping, and surface projects - built with transparent formulas and cited reference data.
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Free Calculators
5
Trade Categories
NEC
Code Tables
DOT
Reference Data
CalcShed is a free library of 75+ construction and trade calculators for concrete, electrical, landscaping, and surface materials, plus home improvement cost estimates. Calculators explain their formulas, assumptions, and relevant reference sources so you can verify the math, not just take a number.
Browse by Category
29 Calculators
Construction
Concrete, roofing, asphalt, gravel, pavers, brick, lumber, and framing tools.
14 Calculators
Electrical
Conduit fill, wire sizing, voltage drop, load calculation, and reference tools.
11 Calculators
Landscaping
Mulch, topsoil, compost, sod, seed, decorative stone, and yard materials.
15 Calculators
Surface
Paint, flooring, tile, siding, drywall, stain, and wallpaper calculators.
6 Calculators
Home Improvement Costs
Drywall, fence, framing, roof, subfloor, and window project cost estimators.
Popular Calculators
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
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Cost
Roof Replacement Cost Calculator
Estimate pitched-roof replacement cost by roof area, pitch, complexity, material, tear-off scope, details, and region.
Cost
Window Replacement Cost Calculator
Estimate insert or full-frame window replacement cost by count, frame, style, size, glass, access, repairs, and region.
Cost
Fence Cost Calculator
Estimate fence installation or replacement cost by measured length, material, height, gates, terrain, removal, and region.
Cost
Drywall Cost Calculator
Estimate drywall installation or replacement cost by surface area, board type, finish level, access, and region.
Cost
Subfloor Replacement Cost Calculator
Estimate subfloor installation or replacement cost by area, scope, panel type, access, floor conditions, and region.
Cost
Framing Cost Calculator
Estimate whole-house light wood framing cost by floor area, stories, scope, floor system, wall height, roof framing, and region.
Recent CalcShed Updates
New calculators, accuracy reviews, and major improvements.Electrical calculator collection reviewed and refined
Calculation logic, units, inputs, references, and usability were reviewed across the electrical collection for consistency, clarity, and practical use.
Home Improvement Cost estimator rebuild completed
The project cost estimator rebuild was completed with clearer scopes, stronger calculation logic, and more useful cost breakdowns across the collection.
Concrete Slab Cost data and visuals expanded
Cost-by-size and regional comparisons were expanded, with clearer material and installed-cost context for planning concrete slab projects.
Tile and Gravel calculators expanded
Tile planning gained full-box ordering details, while Gravel added more geometry, material-density presets, optional cost, and driveway guidance.
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.
Free Calculator Embeds
Add any CalcShed calculator to your website with a responsive widget that supports light and dark mode.
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