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Australia

Concrete Weight Calculator

Enter what you are pouring in metres and millimetres: the calculator gives the cubic metres and, under the results, the weight of the fresh concrete. Handy for a trailer, a suspended floor or a slab you plan to break out and take to the tip.

What are you pouring?
Patio, driveway, shed base, path
Length Width Thickness

Tip: metres and millimetres, or feet and inches if your plans use them, like 10' 6": we convert them.

Reinforcement for slabs (optional)
Gravel base under slabs (optional)

Gravel weight changes from quarry to quarry: ask your supplier for the compacted weight and we turn the volume into tonnes.

Use your own prices (optional)

You need

– m³

–

Poured, it weighs about – kg.

Premixed bags

Bag Bags To carry Est. cost

Mixing it yourself

Cement Australia, General Purpose Cement product data sheet (PDS C01, 2016): mix by volume cement : sand : aggregate and 20kg bags per m³ – high strength 1 : 1.5 : 3 (17 bags), paths and driveways 1 : 2 : 3 (16), foundations and footings 1 : 3 : 3 (13). The sheet gives no water: we use half the cement weight (water/cement 0.5). Kilos of sand and aggregate from 2,400 kg per m³ of fresh concrete, split by the volume parts.

Ready-mix truck

–

How we price

Link to this calculation Download estimate (PDF)

Your materials at a glance

How to calculate concrete

  1. Work out the volume. Length × width × thickness in metres gives cubic metres.
  2. Multiply by 2,400. Normal concrete weighs about 2,400 kg per cubic metre.
  3. Convert to tonnes. Divide kilograms by 1,000: 1 m³ is about 2.4 tonnes.
  4. Check the load. Compare with what your trailer, ute or floor is rated for.

Worked example: a 6 × 6 m garage slab, 100 mm thick

  1. Volume: 6 × 6 × 0.1 = 3.60 m³.
  2. Weight: 3.60 m³ × 2,402.8 kg = 8,650 kg, about 8.6 tonnes.
  3. The calculator adds your waste percentage to the volume, so its weight is a little higher.

Concrete weight by volume

Cubic metres Kilograms Tonnes
0.10 240 0.24
0.25 601 0.60
0.50 1,201 1.20
1.00 2,403 2.40
2.00 4,806 4.81
3.00 7,208 7.21
5.00 12,014 12.01

Normal concrete at 2,403 kg per m³.

Weight of a concrete slab

Thickness kg per m² 6 × 3 m slab (kg) 6 × 6 m slab (kg)
75 mm 180 3,244 6,487
100 mm 240 4,325 8,650
125 mm 300 5,406 10,812
150 mm 360 6,487 12,975
200 mm 481 8,650 17,300

Normal concrete at 2,403 kg per m³.

Concrete formulas by shape

All measurements in metres; divide millimetres by 1,000 first. Results are in cubic metres.

Slab
length × width × thickness
Round slab
π × (diameter ÷ 2)² × thickness
Continuous footing
total length × width × depth
Pad footing
length × width × depth × number of footings
Monolithic slab
length × width × thickness + perimeter band × (edge depth − thickness), where perimeter band = length × width − (length − 2 × edge width) × (width − 2 × edge width)
Bell footing
π × r² × pier height + π × bell height ÷ 3 × (R² + R × r + r²), with r = pier radius and R = bell radius
Wall
length × height × thickness
Column / pier
π × (diameter ÷ 2)² × height
Post hole
(hole area − post area) × depth; round hole π × (diameter ÷ 2)², square hole width²
Tube / ring
π × [(outer ÷ 2)² − (inner ÷ 2)²] × height
Curb & gutter
[curb depth × (curb height + flag thickness) + gutter width × flag thickness] × length
Steps (solid, n steps)
width × rise × run × (1 + 2 + … + n). With a landing, the landing is the top step: width × rise × [run × (1 + … + (n − 1)) + landing depth × n]

1 m³ = 1,000 litres.

Frequently asked questions

How much does 1 m³ of concrete weigh?

About 2,400 kg, or 2.4 tonnes. We use 2,403 kg (150 lb per cubic foot), the same figure as the calculator.

How much does a 100 mm slab weigh per square metre?

About 240 kg per m²; 360 kg at 150 mm.

How much does a 6 × 3 m slab weigh?

At 100 mm thick it is 1.8 m³, about 4,325 kg or 4.3 tonnes.

Does reinforced concrete weigh more?

A little: with reo it is often taken as about 2,500 kg per m³. Lightweight concrete is much lighter, roughly 1,400 to 1,850 kg.

About the prices

Costs are estimated ranges with source and date, never a quote. Enter your local prices under "Use your own prices", or read how we estimate prices.