Calculate how many welded wire mesh sheets or rolls you need, plus mesh weight in lb or kg, from your slab size, mesh style, and wire diameter.
Welded Wire Mesh Formula
The calculator uses a different formula for each mode. To find how many sheets or rolls you need for an area:
To find the weight of US-style mesh per square foot:
To find the weight of metric mesh per square meter:
- L and W are the length and width of the slab, wall, or fence run (ft)
- allowance is an entered overlap and cutting allowance (%); blank defaults to10. This does not calculate required splice lengths or sheet layout
- PA is the coverage of one sheet or roll (sq ft), such as 50 sq ft for a 5 x 10 ft sheet; the result is rounded up to a whole panel
- Wn is the W-number of the wire, which equals its cross-section in hundredths of a square inch (W2.9 = 0.029 sq in)
- s is center-to-center wire spacing (in). The custom formula uses7850kg/m³ steel density and exact unit conversion; no weld-mass multiplier is applied because resistance welding adds no filler metal
- d is the wire diameter (mm) and p is the pitch, the opening plus one wire diameter (mm); 12.33 comes from steel wire weighing 0.00617 * d2 kg per meter in both directions
The coverage mode counts panels and can add total weight and cost when you pick a mesh style and price. The US weight mode reports pounds per square foot, per 100 sq ft, per 5 x 10 ft sheet, or for a total area, and also returns the steel area each way so you can compare the mesh to a rebar layout. The metric mode returns kg/m2 for steel, galvanized steel, stainless 304, or aluminum from the wire diameter and opening, plus per-panel and total weight.
Mesh Styles, Weights, and Rebar Equivalents
The table lists nominal mesh weights from NRCS Table34–2 and steel area each way. The #3 rebar column compares equal steel area only; it does not establish equivalent capacity, crack control, anchorage or permission to substitute reinforcement. Confirm actual supplier weights.
| Style (new / old) | Weight per 100 sq ft | Steel area each way (sq in/ft) | Equal to #3 rebar at |
|---|---|---|---|
| 6×6 W1.4/W1.4 (10 ga) | 21 lb | 0.028 | 47 in o.c. |
| 6×6 W2.1/W2.1 (8 ga) | 30 lb | 0.042 | 31 in o.c. |
| 6×6 W2.9/W2.9 (6 ga) | 42 lb | 0.058 | 23 in o.c. |
| 6×6 W4.0/W4.0 (4 ga) | 58 lb | 0.080 | 16.5 in o.c. |
| 4×4 W1.4/W1.4 (10 ga) | 31 lb | 0.042 | 31 in o.c. |
| 4×4 W2.1/W2.1 (8 ga) | 44 lb | 0.063 | 21 in o.c. |
| 4×4 W2.9/W2.9 (6 ga) | 62 lb | 0.087 | 15 in o.c. |
| 4×4 W4.0/W4.0 (4 ga) | 85 lb | 0.120 | 11 in o.c. |
Common stock formats and their coverage:
| Format | Coverage | Typical use |
|---|---|---|
| Sheet, 5 x 10 ft | 50 sq ft | Slabs, driveways; lies flat, easiest to chair up |
| Sheet, 4 x 8 ft | 32 sq ft | Small pads, countertops, pickup-friendly size |
| Roll, 5 x 50 ft | 250 sq ft | Mid-size slabs; must be flattened before the pour |
| Roll, 5 x 150 ft | 750 sq ft | Large slabs and fencing runs |
Follow project plans and applicable specifications for lap lengths, reinforcement position, cover and supports. These depend on the application and design. Set the allowance from the actual layout;10% is a default estimate and does not guarantee enough mesh.
How to Calculate Welded Wire Mesh
Example 1: sheets for a garage slab. A 24 ft by 30 ft slab is 720 sq ft. With a 10% overlap and waste allowance, you need to buy coverage for 720 * 1.10 = 792 sq ft. Dividing by the 50 sq ft coverage of a 5 x 10 ft sheet gives 792 / 50 = 15.84, which rounds up to 16 sheets. If the mesh is 6×6 W1.4/W1.4 at 0.21 lb per square foot, the 800 sq ft of purchased mesh weighs about 16 * 50 * 0.21 = 168 lb.
Example 2: metric panel weight. A panel is welded from 4 mm steel wire with a 50 mm opening, so the pitch is 50 + 4 = 54 mm. The weight per square meter is 12.33 * 42 / 54 = 12.33 * 16 / 54 = 3.65 kg/m2. A 1.2 m by 2.4 m panel is 2.88 m2, so it weighs 3.65 * 2.88 = 10.5 kg, and ten panels weigh about 105 kg.
FAQ
Does welded wire mesh replace rebar? That requires a design decision. Equal steel area alone does not establish equivalent performance. The6x6W1.4 style supplies0.028in²/ft each way; its equal-area #3 spacing is about47.14in, but anchorage, spacing, strength and serviceability must also satisfy the project design.
How much should welded wire mesh overlap? Use the splice and placement details specified for the project. Required laps depend on reinforcement, concrete, crosswires, coating and other design conditions. The calculator’s allowance estimates purchase area and cannot determine lap length.
Why can delivered mesh weight differ? Stock presets are nominal published values. Custom US and metric results estimate an infinite wire grid; edge-wire counts, dimensions and manufacturing tolerances can differ. Resistance welding adds no filler metal, so no7% weld-mass factor is used. Galvanized modes use an editable assumed coating percentage (blank means5%); actual coating mass depends on wire size and specification. Use supplier data for shipping weights.
