Concrete quantity calculator
The concrete calculator helps you estimate the quantity of concrete from the dimensions of the element. Have the design data ready, and before you order, also check the actual excavation or formwork. The result in m³ is a starting point for a discussion with your contractor and for a quote.
Strip footings
Add up the lengths of all footing sections, including the internal ones. Calculate sections with a different width or height separately. Watch out for junctions and corners: the part shared by two sections should not be counted twice.
Check the actual dimensions before you order. If the concrete is to be placed directly in the trench, uneven sides and wider sections can change the amount used. Do not treat inaccurate workmanship as something the calculator’s margin will cover automatically.
Foundation walls
Have the length, height and thickness of each wall ready. Enter sections that differ separately. Allow for openings and spaces taken up by other elements on the basis of the drawings and the actual design solution.
Do not deduct the volume of reinforcement or openings by guesswork. If their effect is significant, the quantity should be checked by the contractor or the person running the site. This way you avoid a result that looks precise but is based on wrong assumptions.
Slab, floor slab and suspended floor
For a rectangular element you need the length, width and thickness. Divide an irregular area into simpler parts, calculate them separately and add up the results. Include thickenings, beams, downstand beams or ring beams if they have not already been included in the calculation.
A rib-and-block floor is not a solid concrete slab. Multiplying its whole area by its overall depth will overstate the result. Use the concrete schedule in the design or the data for the floor system used, and include any additional elements.
Pad footings and columns
Rectangular pad footings and columns can be calculated from their dimensions. For several identical elements, calculate one volume and multiply it by the number of pieces. For a round column you need the diameter and the height, and the correct formula for the volume of a cylinder.
If the calculator does not offer the right shape, do not replace it with a roughly similar element. Calculate the quantity from the drawings or ask us to check it. Stairs and elements with a varying cross-section need the appropriate data.
How to calculate m³ of concrete
The volume of a rectangular element is length × width × height or thickness. All values in the formula must be in metres. A thickness of 20 cm is 0.20 m.
Worked example: a slab measuring 10 m × 8 m × 0.20 m has a volume of 16 m³. This shows how the formula works; it is not a recommended slab thickness or quantity for any particular site.
For several elements, add up the volumes. The excavation and formwork may differ from the design, and some concrete stays in the equipment. The margin and the rounding of the order are set separately; they do not come from simply multiplying the dimensions.
The calculator adds 5% to the total as a margin and rounds the result up to the nearest 0.5 m³. You can change the margin in the calculator before you calculate.
What to do with the result
Check the dimensions, units and number of elements. Then send the result for a quote together with the location of the site, the date and what you are concreting. Also tell us if you need a pump and about any access difficulties.
The “Send the result for a quote” button opens the quote form with the quantity in m³ already filled in. The form requires a phone number and the town or municipality of the site. If you do not know the other details, you can start with this information. Sending the result does not by itself confirm the delivery or the quantity of concrete ordered.
Questions about the calculation
Is the result the exact quantity to order?
The accuracy depends on the input data and the actual dimensions. The result already includes the margin set in the calculator (5% by default) — do not add it a second time. Before you order, check the result with your contractor and change the margin if they recommend a different one.
My strip footings have different dimensions. How do I calculate them?
Treat each section with different dimensions as a separate element. Then add up the results and check the shared parts at the junctions.
Where do I get the dimensions from?
From the structural part of the design and the concrete schedule, if one has been prepared. Before you order, compare them with the actual excavation or formwork.
How do I calculate a rib-and-block floor?
Use the quantity of concrete given in the drawings for the specific floor system. Add ring beams, beams and other parts separately, unless the schedule already includes them.