🪟 Shuttering / Formwork Calculator PRO
Shuttering area, plywood sheets, release oil, labour & material cost for slab, beam, column & staircase.
Formwork Panel — updates as you type
Member faces with walers. Plywood follows the contact area divided by sheet size.
1 Member Type
2 Member Dimensions
3 Material & Labour Rates
Results
Shuttering Area
Materials
Cost Breakdown
Professional Shuttering Guide
Show formulas, plywood specs & tips ▼
Area Formulas
Slab:Area = L × W (contact area with concrete bottom face)
Beam:Area = 2 × (W + D) × L (bottom + 2 sides)
Column:Area = 2 × (W + D) × L (all 4 faces, L = height)
Staircase:Area = L × W + 2 × (W + D) × L (slab bottom + waist + sides)
Plywood Specifications
| Size | Area | Reuses |
|---|---|---|
| 4 × 8 ft | 32 sq ft | 8-12 |
| 4 × 10 ft | 40 sq ft | 8-12 |
Release Agent Guidelines
- Apply 1 coat before each pour for clean stripping
- Coverage: 40-60 sq ft/L depending on plywood condition
- Used oil is cheaper but may stain concrete — use proper form oil
- Budget 10-15% extra for waste and re-coating
Common Mistakes
- Not allowing for plywood reuses — proper oil extends life significantly
- Ignoring bracing requirements — inadequate support causes blowouts
- Using wrong plywood grade — BWR/BS grade for wet concrete contact
- Skipping edge sealing — raw plywood edges absorb water and swell
- Not factoring waste — always add 10-15% for cuts and damaged sheets
Drag to rotate — Scroll to zoom
Related Calculators
Frequently used together on the same project.
Client & Quote (prints on PDF & Excel)
Adjustments (applies to exports)
Contingency is added as a separate line on the exported cost summary. Waste % is printed as an advisory reminder.
Project notes (prints on PDF & Excel)
Result compare (A/B)
| Item | Pinned | Current | Change |
|---|---|---|---|
Saved rates auto-apply from your Price Library. Advanced details stay in your browser — nothing is uploaded except inside your own PDF/Excel exports.
📖 How to Use the Shuttering Calculator
Measure the concrete surface area to be shuttered in square meters.
Select the formwork type (wall, column, beam, slab, or foundation).
Enter the reuse factor indicating how many times plywood will be reused.
Enter the material cost per unit for plywood, timber, and steel props.
Click Calculate to get material quantities and cost estimates.
Review the detailed breakdown including all components and total cost.
📐 Shuttering Material Formulas
⚠️ Common Shuttering Calculation Mistakes
Underestimating the number of plywood sheets needed due to incorrect reuse factor assumptions.
Not accounting for cutting waste at edges, corners, and around penetrations.
Using incorrect prop spacing which can lead to formwork failure under concrete pressure.
Ignoring the weight of wet concrete which creates significant pressure on vertical formwork.
Not considering the stripping time which affects the number of plywood sets required.
💡 Professional Shuttering Tips
Use high-quality film-faced plywood for a smooth concrete finish and maximum reuse cycles.
Ensure adequate bracing and ties to prevent formwork blowout under concrete pressure.
Calculate the concrete pressure on wall formwork based on pour rate and concrete temperature.
Plan the stripping sequence carefully to avoid damaging green concrete or the formwork.
Apply form oil evenly to plywood surfaces to ensure easy stripping and clean concrete finish.
Inspect all formwork components before each use for damage, warping, or wear.
Keep plywood sheets flat and dry during storage to prevent bowing and delamination.
❓ Frequently Asked Questions About Shuttering
The number of reuses depends on plywood quality and care. Standard plywood can be reused 5 to 8 times. High-quality film-faced plywood can be reused 15 to 25 times or more. Proper cleaning, oiling, and storage significantly extend reuse life.
Common thicknesses are 12mm, 15mm, and 18mm. For walls and columns, 15mm to 18mm plywood is typical. For slabs, 12mm to 15mm may be sufficient depending on prop spacing. Thicker plywood provides better concrete finish and more reuses.
Divide the slab area by the prop spacing area. For props at 1.2m centers, each prop covers 1.44 m². For a 100 m² slab: 100 ÷ 1.44 = 70 props minimum. Add extra props for edge areas and heavy loads.
The pour rate depends on formwork design and concrete pressure capacity. Typical wall formwork can handle pour rates of 2 to 4 meters per hour. Higher pour rates create greater pressure and may require stronger formwork or additional ties.
Stripping time depends on concrete strength gain, temperature, and structural requirements. Walls and columns typically require 12 to 24 hours for sides and 24 to 48 hours for bottoms. Slabs may require 7 to 14 days for full support. Always check concrete strength before stripping.
🏗️ Real-World Shuttering Applications
Use our shuttering calculator to accurately estimate formwork materials, plywood quantities, and costs for your concrete construction project.
✅Method, Sources & Review
Maintained by theBuildingCalc methods desk· Last reviewedSeptember 23, 2026. This calculator implements the standards and references below; every figure can be rechecked against the formulas and worked example on this page.
Results are estimates, not engineering advice. Verify against local codes and licensed professionals for structural, electrical, and gas work. See ourTerms. Spotted an error? Report it— corrections ship with the next review.