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HardHatCalc

Structural Calculators

Free tools for sizing beams, estimating truss costs, calculating load capacity, and planning structural elements of your building project. Each calculator shows the formulas used and includes educational guides below the tool.

Most Popular

Truss Price Calculator

How much will your roof trusses cost? Get a full price breakdown covering materials, labour, and delivery by truss type and span.

Load-Bearing Wall Calculator

Thinking about removing a wall? Check the total load it carries and see what replacement beam size you would need.

Steel Beam Size Calculator

Find the right W-flange, I-beam, or C-channel for your span and load. Returns section modulus, deflection check, and suggested beam sizes.

Shed Roof Truss Calculator

Building shed trusses from scratch? Work out rafter lengths, lumber quantities, truss count, and total cost from your shed dimensions and roof pitch.

Concrete Reinforcement Calculator

Size your rebar order before the pour. Works out bar count, spacing layout, total weight, and tie wire for slabs, footings, and walls.

Wall Framing Calculator

Get a full lumber list for framed walls — studs, plates, headers, king studs, and jack studs — with door and window openings factored in.

Concrete Block Wall Cost

Price out a complete CMU wall project — block count, mortar bags, rebar, and labour — so you know the real cost before breaking ground.

Deck Weight Limit Calculator

Calculate your deck's load capacity based on joist size, spacing, and wood species. Get dead load, live load, and maximum point load estimates.

Wood Beam Cost Calculator

Compare wood beam costs by species, grade, and size. Estimate material prices for Douglas Fir, Southern Yellow Pine, SPF, and LVL beams with hardware costs included.

Shed Foundation Calculator

Compare pier blocks, gravel pads, and concrete slabs for your shed base. Shows material quantities and costs for each foundation type based on shed size and soil.

Pier Footing Size Calculator

Size pier footings based on column load, soil bearing capacity, and frost depth. Get footing width, depth, and concrete volume for decks, porches, and posts.

Deck Joist Span Calculator

Find maximum deck joist spans for 2x6 through 2x12 lumber. Adjust species, spacing, and load to get code-compliant spans and joist counts instantly.

Staircase Dimension Calculator

Calculate stair rise, run, tread count, stringer length, and headroom clearance from floor-to-floor height. Verify building code compliance for residential staircase geometry.

Concrete Slab Weight Calculator

Calculate the weight of a concrete slab by dimensions, thickness, and density. Covers normal-weight, lightweight, and reinforced concrete for structural load planning.

Concrete Curing Time Calculator

Estimate concrete curing time to reach target strength based on mix type, temperature, humidity, and thickness. Plan form removal and loading schedules.

Retaining Wall Block Calculator

Plan the full retaining wall — not just blocks. Covers base gravel, drainage aggregate, filter fabric, and adhesive alongside block count and total cost.

Door Header Size Calculator

Size headers for door and window openings in load-bearing walls. Based on IRC Table R602.7 prescriptive requirements for residential construction.

Concrete Mix Ratio Calculator

Calculate the right amounts of cement, sand, and aggregate for your concrete mix. Supports standard ratios from rich structural mixes to lean fill mixes.

Concrete Pressure Calculator

Estimate lateral pressure on wall and column formwork from fresh concrete. Uses the ACI 347 method with pour rate, temperature, and cement type adjustments.

Beam Deflection Calculator

Check if your beam passes deflection limits. Calculates maximum deflection for simply-supported beams under uniform, centre-point, and third-point loading.

Concrete Footing Calculator

Calculate concrete footing dimensions, volume, and cost for walls and columns. Sizes spread footings based on load, soil bearing capacity, and frost depth.

Floor Joist Size Calculator

Determine the right floor joist size for your span. Calculates minimum joist depth for 2x6 through 2x12 lumber based on span, spacing, species, and load requirements.

Post Size Calculator

Size deck and porch posts correctly. Calculates minimum post cross-section based on load, height, and species for 4x4, 4x6, and 6x6 posts.

Roof Rafter Length Calculator

Calculate rafter length, birdsmouth cuts, and lumber needed for any roof pitch. Enter span, pitch, and overhang to get exact rafter dimensions and cutting angles.

Rebar Lap Splice Calculator

Calculate the required overlap length when splicing reinforcing bars in concrete per ACI 318. Enter rebar size, concrete strength, coating, and splice class to get the lap splice length in inches.

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