Concrete Volume Calculator — m, m³, bags
How to use this calculator
Pick a shape, enter each dimension and choose its unit (m, cm, or mm), then click Add Item to push it onto the takeoff list. Mix slabs, columns, walls, footings, sonotubes, and custom volumes in one pour schedule — the running total in m³, litres, and bags updates as you build the list.
Each item keeps its own shape, dimensions, and volume so you can delete or re-add to match field changes. Add a waste allowance (5–10% is typical, more for over-excavated subgrade) and enable Cost Estimate to price the job by ready-mix delivery (per m³), 50 kg bags, or 25 kg bags. For a single bagged pour, the concrete bag calculator is faster; for reinforced members size steel with the concrete beam and column calculators.
How to Use the Concrete Volume Calculator (Metric)
Build a takeoff one element at a time: choose slab, column, wall, footing, sonotube, or a custom volume, enter each dimension with its unit (m, cm, mm), then Add Item. The list keeps every member so you can price one continuous ready-mix order instead of guessing per element. Plants typically supply in 0.25 m³ steps and apply a part-load charge below about 3–4 m³, so the cost panel lets you compare truck delivery against bagged mix for small pours.
Concrete Volume Formulas
Slab / footing / wall: Length × Width × Thickness (rectangular prism)
Round column / sonotube: π × (D/2)² × Height × Qty
Square column: Side × Side × Height × Qty
All inputs convert to metres, multiply for m³; 1 m³ = 1 000 litres. Weight uses normal-weight concrete at 2 400 kg/m³ per Eurocode 2 (EN 1992-1-1); lightweight or grout mixes weigh less. The waste slider scales the net volume up before bag and truck counts are derived.
Bag Coverage & Field Notes
A 50 kg bag yields ≈0.024 m³ (24 litres); a 25 kg bag ≈0.012 m³ (12 litres); bag counts here round up because partial bags are not sold. Above roughly 1 m³ ready-mix is usually cheaper and gives consistent strength per EN 206. For reinforced members size the steel with the beam rebar calculator or column rebar calculator; for site work see the wall, kerb & gutter, and stairs calculators.
FAQ
How much waste should I add? 5% for a formed slab on a level base, 10% for typical work, 15–20% for footings on rough or over-excavated subgrade where concrete slumps into the soil.
Can I mix shapes in one order? Yes — that is the point of the takeoff list; all items sum into one m³ and bag total so you place a single ready-mix order.
Which currency should I use? Choose from 10 currencies common across the EU and EEA in the settings below the results; the symbol updates the price inputs and totals.
On pour day
Three things estimators forget when calling the batching plant. Part-load fee — most plants charge an extra €30–80 below ~3 m³, so a 3×3 m shed slab (≈0.9 m³ at 100 mm) is often cheaper in 25 kg bags or with a small site mixer. Strength class — driveways, exterior slabs and freeze-thaw exposure need C30/37 or higher with the right XF exposure class (EN 206); upgrading from C20/25 typically adds €5–15/m³. Pump — anything past 30 m of hose, upper-floor decks, or columns up tight walls needs a line or boom pump (€300–700 minimum on top of the mix). Round the truck order up to the next 0.25 m³ and add a buffer for over-excavated footings — a second trip costs more than a few extra litres.
