Concrete Slab Calculator — m, cm to m³, bags, cost
How to use this calculator
Enter slab dimensions and choose the unit (m, cm, or mm) from the dropdown next to each input. Choose from five shapes — rectangle, circle, triangle, L-shape, or direct area — set thickness and waste allowance. Results update instantly.
Cost — pick ready-mix delivery per m³, 50 kg bags, or 25 kg bags. Select your currency (EUR, PLN, CZK, SEK, etc.) in the settings below.
Reinforcement — welded wire mesh per EN 10080 or rebar Ø8–Ø20 with spacing 100–300 mm per EN 1992-1-1 (Eurocode 2), including lap splices and concrete cover.
Labor — rate per m², per m³, or a flat price. Grand total sums all active sections.
Saved Calculations
| Time | Shape | Area m² | Vol m³ | Cost | Rebar | Qty | Rebar | Labor | Total |
|---|
How to Calculate Concrete for a Slab (Metric)
This concrete slab calculator estimates volume in cubic meters, number of pre-mixed bags (25 kg and 50 kg), total weight in kilograms, material cost, reinforcement requirements, and labor expenses for rectangular, circular, triangular, L-shaped slabs, or by direct area input in square meters. Enter dimensions and choose the unit (m, cm, or mm) from the dropdown, set the slab thickness (standard: 10 cm for patios, 12–15 cm for driveways, 20 cm for heavy-duty), and adjust waste allowance from 5% to 20%.
Reinforcement per EN 1992-1-1 (Eurocode 2)
Choose welded wire mesh (WWM Q188, Q257, or Q335 per EN 10080) or B500B rebar Ø6 through Ø20 with spacing from 100 to 300 mm on center. The calculator accounts for lap splices at 40db per EN 1992-1-1 §8.7, concrete cover per exposure class (XC1–XC4, XD/XS per EN 1992-1-1 §4.4.1), and cutting waste. Standard bar length is 6 m and WWM sheets are 2.4 m × 6 m (14.4 m²).
Cost Estimation
Compare ready-mix delivery pricing per cubic meter against bagged concrete (50 kg ≈ 0.024 m³, 25 kg ≈ 0.012 m³). Choose from 10 currencies used across the EU and EEA (EUR, PLN, CZK, SEK, DKK, NOK, HUF, RON, BGN, CHF, GBP). Concrete density is 2,400 kg/m³.
Export & Save
Save calculations to the built-in history table and export results as formatted text, CSV spreadsheet, A4 portrait JPG image, or a single-page PDF with diagram and data. All estimates are for planning purposes — consult a licensed structural engineer for load-bearing applications.
