Total Concrete Required
—
cubic metres (including wastage)
Accurate concrete volume estimates for slabs, footings, columns and steps in Cairns
Calculate exact concrete quantities, bag counts, and 2026 cost estimates for your Cairns construction project. Free, instant results for DIY and professional builders across Far North Queensland.
Professional concrete calculations for residential and commercial projects across Cairns and Far North Queensland
Calculate the exact cubic metres of concrete required for your Cairns project. Whether you're pouring a house slab, footings for a Queenslander-style home, a pool surrounds slab, or post holes for a deck, our calculator delivers precise results — including wastage factors suited to Cairns' tropical soil conditions and high-moisture environments.
Get instant cost estimates using 2026 ready-mix pricing for the Cairns region. Far North Queensland construction costs differ from southern cities due to freight, tropical mix specifications, and seasonal wet season constraints. Compare ready-mix versus premix bag options to find the most cost-effective solution for your project size and location.
Designed for Cairns builders, concreters, and owner-builders working in a tropical climate. Covers concrete slabs, strip footings, circular columns, and stair steps — all factoring in Cairns-specific exposure classifications for high humidity, cyclonic conditions, and aggressive soil environments. Pair with our Balcony Slab Calculator for elevated deck bases.
Select your project type and enter dimensions to calculate concrete volume and cost
Using our Cairns Concrete Calculator is quick and simple. Select your project type — slab, footing, column, or steps — enter your dimensions, choose your concrete grade and supply method, then click Calculate. The tool instantly outputs your total concrete volume in cubic metres, bag counts, and a 2026 cost estimate based on Cairns and Far North Queensland pricing.
Cairns sits in a tropical climate zone with high humidity, heavy wet season rainfall, and aggressive soil conditions in many suburbs. Always use a minimum 25 MPa concrete for all external slabs and footings, specify Class B1 or B2 exposure classification as per AS 3600, and increase your wastage factor to 15% for any projects during or immediately after the wet season (November–April) when ground conditions are softer.
Standard Cairns domestic slab: 100 mm thickness with SL82 mesh, a 200-micron vapour barrier, and compacted road base sub-base. Elevated slabs on stumps are also common in the region for Queenslander-style homes.
Our Cairns Concrete Calculator uses standard Australian construction formulas consistent with AS 3600 and Queensland building requirements. All dimensions are converted to metres before calculation for accurate cubic metre outputs.
Residential floor slabs in Cairns are typically poured at 100 mm thickness for ground-bearing slabs. Driveways and carport pads require 125–150 mm. In areas with high-moisture or reactive soils — common across suburban Cairns and Northern Beaches — a waffle pod raft slab engineered to AS 2870 is frequently specified to manage ground movement.
Ready-mix concrete in Cairns averages $260–$330 per m³ depending on grade, mix design, and delivery location. Outer suburbs and rural properties north or south of Cairns — such as Palm Cove, Mossman, or Gordonvale — may attract distance surcharges of $20–$50 per m³. A short-load fee of $100–$200 applies for orders under 3 m³ from most suppliers.
Due to Cairns' tropical environment, 25 MPa is the minimum recommended grade for all external slabs, paths, and footings. Use 32 MPa for driveways and exposed pool surrounds, and 40 MPa for structural elements in cyclone-rated buildings. AS 3600 exposure classification B1 applies to most Cairns residential external work, increasing concrete cover requirements.
Cairns receives an average of 2,000 mm of rain per year, with the majority falling between November and April. Avoid pouring concrete during heavy wet season rain — water diluting the surface weakens the slab permanently. If wet season work is unavoidable, use a Type HE (high early strength) or water-reduced admixture and always have shade cloth or plastic sheeting on standby to protect fresh pours.
Buildings in Cairns must comply with Queensland Development Code Part 1.3 — Cyclone Design Requirements. Concrete footings for cyclone-rated structures typically require deeper embedment depths, increased reinforcing, and higher-strength concrete than standard residential builds. Always engage a structural engineer for new home footings — cyclonic wind region C applies to Cairns under AS 1170.2.
For Cairns projects over 1 m³, ready-mix truck delivery is more economical and produces a more consistent tropical mix than hand-batched bags. Premix bags are ideal for post holes, small garden steps, or repair jobs under 0.5 m³. Note that Cairns' heat means concrete sets faster — if using premix bags outdoors, mix in smaller batches and work in the early morning before peak temperatures to avoid premature setting.
The following table shows typical 2026 concrete costs for common project types across the Cairns region. Ready-mix prices include standard delivery within the Cairns urban area. Remote Far North Queensland properties may incur additional freight charges.
| Project Type | Volume (m³) | Ready-Mix Cost | Premix Bags (20 kg) | Bag Cost (approx) | Notes |
|---|---|---|---|---|---|
| Small Slab (3×3×0.1m) | 0.99 m³ | $310–$375 | ~110 bags | $880–$1,210 | Bags practical for under 1 m³ |
| House Slab (10×8×0.1m) | 8.8 m³ | $2,640–$3,170 | ~978 bags | $7,820–$10,760 | Ready-mix essential; specify 25 MPa |
| Driveway (10×3×0.15m) | 4.95 m³ | $1,485–$1,785 | ~550 bags | $4,400–$6,050 | Use 32 MPa; add sealer in Cairns heat |
| Strip Footing (20m×0.4×0.3m) | 2.64 m³ | $792–$950 | ~295 bags | $2,360–$3,245 | Check cyclone tie-down specs |
| Deck Post Holes (300mm×1.5m, ×8) | 0.85 m³ | $255–$310 | ~95 bags | $760–$1,045 | Common for elevated Queenslanders |
| Pool Surrounds (30m²×0.1m) | 3.3 m³ | $990–$1,190 | ~367 bags | $2,936–$4,037 | Use 32 MPa; chemical-resistant mix |
Ready-mix truck delivery is the best choice for any Cairns project over 1 m³ — it gives a consistent tropical mix formulated for high humidity and produces a stronger result than hand-mixed bags. For small jobs like deck post holes or repair patches under 0.5 m³, premix bags work well. Important: in Cairns' tropical heat, concrete sets faster than in southern states — have all your formwork, mesh, and crew ready before the truck arrives, and avoid afternoon pours during the wet season.
Concrete construction in Cairns presents unique challenges due to the tropical climate, high moisture levels, and cyclonic design requirements. The following tips will help your project succeed first time.
Cairns soils range from sandy coastal soils at the Esplanade and Northern Beaches to clay-rich ground in southern suburbs like Gordonvale and Edmonton. Proper sub-base preparation is critical — always compact road base to 95% standard proctor compaction before pouring, and ensure adequate drainage fall of at least 1.5% on all outdoor slabs. Standing water under slabs accelerates deterioration in the tropical environment.
Major concrete suppliers servicing Cairns include Boral, Hanson, and local independent ready-mix operators. When ordering, always specify the slump class (typically S3: 100 mm for flatwork), exposure classification (B1 for most external residential work in Cairns), and maximum aggregate size (14 mm for slabs, 20 mm for footings). Inform your supplier if you require a water-reducing admixture for workability in the heat, or a retarder to extend working time during hot weather pours. Visit our Admixture Dosage Calculator to estimate the correct admixture volumes for your mix design.
Never pour concrete during heavy rain or on a waterlogged sub-base. Rain falling on fresh concrete dilutes the cement paste and permanently weakens the surface layer — this is especially critical in Cairns where tropical downpours can arrive with little warning. Always monitor the Bureau of Meteorology forecast for Cairns the day before and morning of any concrete pour, and have waterproof sheeting ready to cover fresh pours if a shower passes through.
For a 10×8m slab at 100 mm thick: 10 × 8 × 0.1 = 8.0 m³ net volume. Adding the recommended 10% wastage factor gives 8.8 m³ to order. For a ground-bearing slab in Cairns, always specify a minimum 25 MPa tropical mix with SL82 reinforcing mesh and a 200-micron vapour barrier. If your engineer has specified a raft or waffle pod slab due to reactive soils, the volume will be higher — use the exact dimensions from your engineer's drawings for accurate ordering.
Use a minimum of 32 MPa concrete for driveways in Cairns. The combination of vehicle loads, UV exposure, high humidity, and thermal cycling in the tropical climate demands a stronger mix than standard residential slabs. Specify a Class B1 or B2 exposure classification depending on your proximity to the coast — Cairns Esplanade and beachfront properties should use B2 minimum. Adding a penetrating concrete sealer after curing is also strongly recommended to protect driveways from staining, water ingress, and salt spray in coastal areas.
Yes. Cairns falls within Wind Region C under AS 1170.2, requiring cyclone-compliant construction. Strip and pad footings for cyclone-rated homes must be designed by a structural engineer and typically exceed standard residential depths. Most Cairns engineered footings range from 450–600 mm deep, with specific reinforcing and hold-down anchor systems embedded in the concrete. Never use generic footing dimensions for a new Cairns home — always obtain an engineer's footing design that references the site classification from your geotechnical report.
It's possible but requires careful planning. Never pour during active rainfall or on a saturated sub-base. If wet season work is unavoidable, schedule pours for early morning before afternoon storms, use a Type HE cement or accelerating admixture to speed up early strength gain, and keep waterproof sheeting readily available. Ensure all formwork drainage is adequate, and brief your team to act quickly if rain approaches. For major pours like house slabs, most experienced Cairns concreters prefer to schedule work between May and October (dry season) for best results.
At 100 mm thickness, you need approximately 11 bags of 20 kg premix per square metre. At 150 mm thickness, this increases to around 17 bags per m². Each 20 kg bag yields approximately 0.009 m³ when mixed to the standard ratio. For Cairns tropical conditions, ensure you're using a premix product rated for tropical or outdoor use — standard indoor premix may not provide the durability needed for Cairns external conditions. For any area over 4 m², ready-mix concrete delivers better quality and value.
The dry season (May to October) is the ideal time to pour concrete in Cairns. Temperatures are moderate (24–28°C), humidity is lower, and rainfall is minimal — perfect conditions for consistent hydration and curing. During the wet season (November–April), high temperatures, afternoon storms, and heavy rainfall all create challenges. If you must pour in the wet season, start early in the morning, have your crew and materials staged, use a retarding admixture if temperatures exceed 30°C, and always check the BoM Cairns forecast before the pour.
Our Cairns Concrete Calculator is ideal for preliminary volume and budget estimating for residential and light commercial projects. For structural commercial work — including columns, suspended slabs, cyclone-rated commercial buildings, or marine structures near Trinity Inlet — always engage a licensed structural engineer to specify concrete grades, reinforcement, mix designs, and exposure classifications. Calculator outputs are indicative for planning purposes and should be confirmed with your concreter and engineer before placing orders on large or complex commercial projects.
Access local development application requirements, building approvals, and site-specific planning controls for construction projects across the Cairns local government area.
Visit Council Website →Queensland Development Code Part 1.3 outlines cyclone construction requirements for Cairns and Far North Queensland. Essential reading for new builds and major renovations in Wind Region C.
QDC Guidelines →Explore the full library of free construction calculators at ConcreteMetric — covering aggregates, admixtures, retaining walls, slabs, and more for Australian projects.
Browse All Calculators →