Concrete & Area Calculator
Work out the area and the concrete you need for a slab, path, shed pad or post holes.
This gives an area and concrete volume estimate only. Leave any part at 0 if you don't need it. Everything is worked out in your browser. Nothing is saved or sent anywhere.
1. Slab, path or pad
Measure the finished size. Use the average thickness if the ground isn't level.
Check the plans or the shed maker's slab detail.
For several pads the same size.
2. Post holes or footings
Round holes. Set the post size to 0 for a solid footing with no post in it.
The post takes up room, so it is taken off the concrete. 0 for none.
3. Ordering
Premix bag yields vary by brand and bag size, so check the bag.
Extra for uneven ground, spillage and overfill.
Many 20 kg premix bags make about 0.01 m³. Check the bag.
For the total weight to carry.
Results
How it was worked out
Before you rely on it
- This is an area and volume estimate only. It isn't a slab or footing design. Thickness, reinforcement, footing size and concrete strength should come from the plans, the shed or building maker, or an engineer.
- Ready-mix suppliers sell by the cubic metre and may have minimum loads or short-load fees, so ask your supplier.
- Check with your council whether the slab or shed needs approval, and call Before You Dig Australia (1100.com.au) before digging.
- Wet cement and concrete can burn skin and eyes. Wear gloves, eye protection and long sleeves, and follow the safety information on the bag.