3-4-5 Method Calculator
Verify 90-degree corners using the 3-4-5 method
Balustrade Spacing Calculator
Calculate compliant baluster spacing per NCC 125mm sphere rule
Beam Span Calculator
Look up maximum timber beam spans per AS 1684
Besser Block Calculator Australia
Calculate concrete blocks needed for a wall including mortar
Brick
Calculate bricks, mortar, sand, and cement per square metre
Compound Miter Calculator
Calculate miter and bevel angles for crown moulding
Concrete Bag Calculator
Calculate how many bags of premix concrete you need
Concrete Block Fill Calculator Australia
Calculate core fill concrete volumes for block walls
Concrete Cost Calculator
Estimate concrete costs including delivery and surcharges
Concrete Pier Calculator (Australia)
Concrete Quantities
Calculate cement, sand, and aggregate for site-mixed concrete
Concrete Volume Calculator
Calculate cubic metres for slabs, footings, and cylinders
Deck Board Spacing Calculator
Calculate even board layout and adjusted gap size
Decking
Calculate decking boards, joists, bearers, and fixings
Equal Spacing Calculator
Calculate equal gaps between posts, balusters, or fixings
Fence Post Spacing Calculator (AU)
Fencing Calculator
Calculate posts, rails, palings, and concrete for fences
Flooring Calculator
Calculate flooring area and boxes for any laying pattern
Gutter Calculator
Size gutters and downpipes by catchment and rainfall intensity
How Many Bricks Per M2?
Quick lookup for bricks per m² by brick size and mortar joint
Insulation Calculator
Calculate insulation batts with NCC R-value guide by climate zone
Insulation R-Value Calculator (NCC 2022)
M3 Calculator
Calculate cubic metres for rectangular or cylindrical shapes
Material Weight Calculator
Calculate weight of construction materials by volume
Miter Angle Calculator
Calculate the saw miter angle for any corner angle
Mortar Calculator
Calculate mortar volumes and bags for brickwork and blockwork
Overhead Calculator
Calculate overhead percentage, markup, and break-even multiplier
Paint Calculator
Calculate litres of paint needed based on area and coats
Pier & Beam Footing Calculator
Plumbing Fall Calculator
Calculate minimum pipe fall and grade per AS/NZS 3500
Pool Volume Calculator
Calculate pool volume in litres for any pool shape
Property Cost Calculator
Estimate property construction costs per m² or builder square
Raked Wall Calculator
Calculate stud lengths for raked walls and skillion roofs
Ramp Calculator (AU AS 1428.1)
Retaining Wall Block Calculator
Retaining Wall Calculator
Calculate sleepers, posts, and concrete for retaining walls
Roof Pitch Calculator
Convert between degrees, rise/run ratio, and percentage
Roof Rafter Calculator
Calculate rafter length, birdsmouth cuts, and timber sizes
Roofing Calculator
Calculate true roof area with pitch multiplier and waste
Running Measurements Calculator
Convert individual measurements to cumulative running dimensions
Slope & Grade Calculator
Convert between percentage, ratio, and degrees for site falls
Soil & Gravel Calculator
Calculate volume, weight, and truck loads for bulk materials
Stair Calculator Australia
Calculate rise, going, 2R+G formula, and stringer length per NCC
Stair Stringer Cut Calculator (AU NCC)
Tank Volume Calculator
Tile Calculator
Calculate tiles needed including waste for any layout pattern
Triangle Calculator
Solve triangles — sides, angles, and area for builders
Truss Spacing Calculator (AU AS 1684)
Unit Converter
Convert between metric and imperial for construction units
Wall Framing Calculator
Calculate studs, plates, noggins, and lineal metres per AS 1684
Free Builders Calculator — 45+ Construction Calculators Australia
Built Simple offers a comprehensive suite of free construction calculators designed specifically for Australian builders, carpenters, concreters, and tradespeople. Every calculator follows Australian Standards (AS) and the National Construction Code (NCC), so you can trust the results on site.
Whether you are estimating materials for a residential build, checking compliance with building codes, or quickly calculating dimensions on the job, our builders calculators save you time and reduce costly errors.
Concrete Calculators
| Concrete Volume Calculator | Calculate cubic metres of concrete for slabs, footings, paths, and piers. Includes waste factor. |
| Concrete Cost Calculator | Estimate concrete costs including delivery, pumping, and finishing for Australian projects. |
| Concrete Quantities — Slab | Calculate cement, sand, and aggregate quantities for concrete slabs. |
| Concrete Quantities — Holes | Calculate concrete volumes for circular holes, piers, and post footings. |
| Concrete Block Calculator | Calculate the number of concrete blocks (besser blocks) needed for a wall including mortar. |
| Block Fill Calculator | Calculate core fill concrete volumes for 90mm to 290mm series block walls. |
| Concrete Bag Calculator | Calculate how many bags of premix concrete you need by volume and bag size. |
| Cubic Metre (m³) Calculator | Calculate cubic metres for rectangular or cylindrical shapes — concrete, gravel, mulch, and more. |
Roofing & Guttering Calculators
| Roofing Calculator | Calculate roofing materials including sheets, tiles, battens, and fixings for any roof area. |
| Roof Pitch Calculator | Convert between degrees, rise/run ratio, and percentage for any roof pitch. |
| Roof Rafter Calculator | Calculate rafter length, birdsmouth cuts, and timber sizes for any roof pitch and span. |
| Gutter Calculator | Size gutters and downpipes based on catchment area and rainfall intensity (AS/NZS 3500.3). |
Wall & Framing Calculators
| Wall Framing Calculator | Calculate studs, plates, noggins, and total lineal metres for wall framing (AS 1684). |
| Raked Wall — Two Heights | Calculate stud lengths for raked walls using two known wall heights. |
| Raked Wall — Pitch | Calculate stud lengths from roof pitch angle for raked wall framing. |
| Brick Calculator | Calculate bricks needed per square metre including waste and mortar for Australian standard bricks. |
| Bricks Per m² Calculator | Quick lookup for how many bricks per square metre based on brick size and mortar joint. |
| Mortar Calculator | Calculate mortar volumes and 20kg bags needed for brickwork, blockwork, and rendering. |
| Retaining Wall Calculator | Calculate materials for timber sleeper retaining walls including posts and concrete. |
| Insulation Calculator | Calculate insulation batts needed with NCC 2025 R-value guide by climate zone. |
| Beam Span Calculator | Look up maximum beam spans for timber bearers, joists, rafters, and lintels (AS 1684). |
Stairs, Decking & Balustrade Calculators
| Stair Calculator | Calculate rise, going, 2R+G formula, stringer length and number of treads per NCC. |
| Decking Calculator | Calculate decking boards, joists, bearers, and fixings for any deck size. |
| Deck Board Spacing Calculator | Calculate even board layout and adjusted gap size for a perfectly spaced deck. |
| Balustrade Spacing — Flat Run | Calculate flat run balustrade spacing for level sections of balcony and deck railings. |
| Balustrade Spacing — Flat Run (Attached) | Calculate baluster spacing for face-fixed balusters on flat run sections. |
| Equal Spacing Calculator | Calculate equal gaps between posts, balusters, or any evenly spaced items. |
Plumbing & Drainage
| Plumbing Fall Calculator | Calculate minimum pipe fall and grade for drainage per AS/NZS 3500.2. |
| Pool Volume Calculator | Calculate pool volume in litres for rectangular, circular, oval, and kidney-shaped pools. |
Finishing & Surfaces
| Tile Calculator | Calculate tiles needed for floors and walls including cuts, waste, and adhesive. |
| Paint Calculator | Calculate litres of paint needed for walls and ceilings based on area and coats. |
| Flooring Calculator | Calculate flooring area and boxes needed for straight, diagonal, or herringbone layouts. |
Outdoor & Landscaping
| Fencing Calculator | Calculate fencing materials including posts, rails, palings, and concrete for post holes. |
| Soil & Gravel Calculator | Calculate volume, weight in tonnes, and truck loads for soil, gravel, sand, and mulch. |
Measurement & Conversion Tools
| Check Square Calculator | Verify 90-degree corners using the 3-4-5 method and diagonal measurements. |
| Triangle Calculator | Solve triangles — find sides, angles, and area using SSS, SAS, or base and height. |
| Miter Angle Calculator | Calculate the saw miter angle for any corner angle — simple cuts for trim and framing. |
| Compound Miter Calculator | Calculate miter and bevel angles for crown moulding and angled joinery. |
| Slope & Grade Calculator | Convert between percentage, ratio, and degrees for site falls and drainage grades. |
| Running Measurements Calculator | Convert individual measurements to cumulative running dimensions for setting out. |
| Unit Converter | Convert between metric and imperial for length, area, volume, and weight. |
| Material Weight Calculator | Calculate weight of construction materials by volume — concrete, steel, timber, and more. |
Business & Estimating
| Property Cost Calculator | Estimate total property construction costs per square metre or builder’s square. |
| Overhead Calculator | Calculate overhead percentage, required markup, and break-even multiplier for builders. |
Why Use Built Simple Calculators?
- Australian Standards compliant: All calculators follow NCC, AS 1684, AS 3600, AS 3700, and other relevant Australian Standards
- Free to use: No sign-up, no paywall, no limits. Use them on site from your phone
- Built by builders: Designed with input from Australian residential builders, not generic international tools
- Mobile-friendly: Responsive design works on any phone, tablet, or desktop browser
- Regularly updated: Kept current with latest NCC amendments and material prices