Steel mesh calculator
Welded reinforcement mesh is laid in overlapping sheets so the reinforcement is continuous. The calculator adds the overlap to the area and divides by the sheet area.
Your measurements
Result
- Area incl. overlap
- 33.00 m²
- Mesh sheets needed (2 × 3 m)
- 6 pcs
For 2 × 3 m sheets (6 m²). For other sheet sizes divide by their area.
How the calculation works
- Area with overlap = area + overlap percentage (10% by default).
- Sheets = area with overlap ÷ 6 m² (a standard 2 × 3 m sheet), rounded up.
Worked example
For a 30 m² slab with 10% overlap you need 33 m² of mesh: 33 ÷ 6 = 5.5, so 6 sheets of 2 × 3 m.
What the calculator assumes
- Sheets usually overlap by at least one mesh square so the reinforcement is continuous.
- Mesh sits on spacers so it ends up inside the concrete, not at the bottom.
When to adjust the result
- Wire diameter and mesh size (for example 4–6 mm wire, 10–15 cm mesh for paths and reinforced screeds) depend on the load; for structural slabs the project specifies them.
- Non-rectangular areas need cut sheets, which can increase consumption.
- Sheet sizes vary by country (for example 2.15 × 5 m or 2.4 × 4.8 m) — divide by the area of the sheets you buy.
Using steel mesh in slabs
Mesh controls cracking and spreads loads, but only if it sits at the right depth. Lift it on chairs or spacers so concrete gets underneath — mesh lying on the ground does almost nothing. In slabs on the ground it usually goes about a third of the way down from the top, or as the design states.
Overlap sheets by at least one or two grid squares (or the lap given in the design) and tie them together. Cut mesh with bolt cutters or a grinder and wear gloves — the cut ends are sharp. Joints and saw cuts in the slab still need planning; mesh does not replace them.
Frequently asked questions
How much should mesh sheets overlap?
At least one mesh square, and often more for structural work — the engineer or the mesh supplier gives the required lap.
Does a garden path need mesh?
Not always, but a light mesh helps control cracking in concrete paths and slabs, especially over less stable ground.
Is mesh enough for a garage floor?
Often for a light domestic slab on well-compacted ground, but heavy loads or poor soil need a designed slab; ask an engineer if unsure.
How much should mesh sheets overlap?
At least one or two full grid squares, or the lap the structural drawing specifies, tied at regular intervals.