Welded Wire Mesh Calculator
How many sheets or rolls of welded wire mesh (6x6 W1.4/W1.4, 6x6-10/10 and heavier) for a concrete slab: layout with laps, total mesh area, weight and rolls of 2.5 × 40 m or 5 × 150 ft.
How it works
pieces along a side = ⌈(side − lap) ÷ (sheet side − lap)⌉ · sheets = pieces along × pieces across (best of both orientations) · rolls = ⌈strips × strip length ÷ roll length⌉ · weight = mesh area × kg/m² (6x6-10/10 ≈ 1.03 kg/m²)
Welded wire reinforcement for slabs on ground, sidewalks and toppings comes in flat sheets or rolls, most often with 6 × 6 in (15 × 15 cm) openings. Adjacent pieces must overlap so the mesh acts continuously: ACI 318 asks for a lap of at least one mesh spacing plus 2 inches (about 20 cm) for structural mesh, and many contractors use one full square on simple slabs. The calculator tries the sheets both ways round and keeps the layout that needs fewer pieces; for rolls it cuts strips across the shorter direction. Weights use the Wire Reinforcement Institute style designations — 6x6-10/10 (W1.4) is about 21 lb per 100 ft².
Worked example
A 6 × 4 m slab with 2.5 × 6 m sheets and ACI laps (20.3 cm): along the 6 m side one sheet length fits; across the 4 m side ⌈(4 − 0.203) ÷ (2.5 − 0.203)⌉ = 2 sheets — so 2 sheets of 2.5 × 6 m, 30 m² of 6x6-10/10 mesh weighing 30.9 kg.
Sources: Wire Reinforcement Institute — WWR manual · ACI 318-19 §25.5.4 — Lap splices of welded wire reinforcement
Frequently asked questions
How much should welded wire mesh overlap?
For structural use, ACI 318 requires the outermost cross wires of each sheet to overlap by at least one mesh spacing plus 2 in (50 mm) — about 8 in or 20 cm for 6x6 mesh. On simple slabs on ground one full square (6 in) is common practice.
What does 6x6-10/10 mean?
Wires 6 in apart both ways, gauge 10 in both directions (about 3.4 mm, designation W1.4/W1.4). It weighs roughly 21 lb per 100 ft² (1.03 kg/m²) and is the standard mesh for house slabs and sidewalks.
How many m² does a roll of mesh cover?
A 2.5 × 40 m roll is 100 m² before laps — about 90 m² of slab after a 20 cm lap; a 5 × 150 ft roll is 750 ft².
Where should mesh sit in the slab?
In the upper third to middle of the slab on chairs or blocks, not on the ground; mesh lying at the bottom does almost nothing to control cracks.
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This calculator is for educational purposes. Double-check important results before acting on them.