Free Construction Calculators
Instant material quantities, cost estimates, and structural sizing for contractors, tradespeople, and DIY homeowners. Built from hands-on renovation experience.
Popular Tools
Shed Roof Truss Calculator
Calculate rafter lengths, lumber needs, and costs for your shed roof truss project.
Weld Time Calculator
Estimate welding time, filler material, and labour costs by process type.
Truss Price Calculator
Get material and labour cost estimates for roof trusses by type and span.
Square Feet to Percentage
Convert area measurements to percentages for real estate and building projects.
Parking Lot Size Calculator
Plan parking lot dimensions with ADA compliance and paving cost estimates.
Wall Framing Calculator
Count studs, plates, and headers needed for framing walls with door and window openings.
Structural Calculators
Beam sizing, truss pricing, load calculations, deck capacity, wall framing, and foundation tools.
Browse Structural ToolsMaterials & Cost Calculators
Paint coverage, roofing bundles, tile adhesive, welding time, parking lot sizing, and more.
Browse Materials ToolsConstruction Guides & Cost Breakdowns
How-to guides, cost breakdowns, and material comparisons for construction projects. Each guide includes interactive calculators to help you plan your work.
Why HardHatCalc?
Every calculator on this site uses published construction formulas and real-world data. The tools are built by a web developer who recently renovated a property in Northumberland, UK — room expansion, structural work, roofing, insulation, and everything in between. The calculators provide estimates for planning purposes. For structural work, always consult a licensed engineer.