Shuttering Calculator

Why Contractors Lose Money Here

Formwork can cost as much as the concrete it holds. It is paid by contact area, so the measurement must match the faces the concrete actually touches, and the plywood must be reused as often as possible.

Real Site Example

A 230 × 450 mm column, 3 m high: 2 × (0.23 + 0.45) × 3 = 4.08 m² (44 sq ft). A 230 × 450 mm beam, 4 m long, under a 125 mm slab: (0.23 + 2 × 0.325) × 4 = 3.52 m². A 4 × 3 m slab, 125 mm thick: 12 + 1.75 = 13.75 m².

Professional Best Practices

Measure formwork by contact area, agree the method with the client before billing, and keep a reuse log for each set of plywood and props.

Engineering Checklist

• Columns: perimeter × height
• Beams: bottom plus both sides below the slab
• Slabs: soffit plus edges; do not count beam tops twice
• Footings: sides only, no bottom
• Oil the plywood and clean it after every use

Government & Standards References

• IS 1200 (Part 5) — Method of measurement: formwork
• IS 14687:1999 — Guidelines for falsework for concrete structures
• IS 456:2000 — Clause 11 (formwork) and stripping times

How Experienced Contractors Handle This

Contractors plan formwork sets floor by floor, track reuse cycles, and bill contact area measured on the drawings.