Joint Compound Calculator
How much joint compound, paper tape and screws a plasterboard job needs from the area of board — for taping and the number of finishing coats you plan.
Finishing plasterboard uses about 0.
How the joint compound calculator works
Finishing plasterboard uses about 0.15 litres of ready-mixed compound per square metre per coat — a tape coat plus two finishing coats is the usual three. Tape runs along every joint: sheets laid the standard way give roughly 1.2 metres of joint per square metre of board. Screws go every 300 mm on studs at 450 mm centres — about 15 per square metre. Add 10% to everything for waste.
Formula: compound = area × 0.15 L × coats × 1.1; tape = area × 1.2 m × 1.1; screws = area × 15
Worked examples
| Inputs | Compound to buy | Note |
|---|---|---|
| 60 m², three coats, 15 L buckets | 2 × 15 L | 30 L — 2 buckets; 79 m of tape |
| 650 sq ft, three coats, 4.5-gallon buckets | 2 × 17 L | 30 L — 2 buckets |
| A single room, 25 m², two coats | 1 × 12 L | 8.3 L — 1 bucket |
FAQFrequently asked questions
Ready-mixed or powder?
Ready-mixed (all-purpose) is easiest and what the litre figure assumes. Setting-type powder (20-minute, 45-minute) sets chemically, is stronger for the tape coat and comes in bags — 20 kg makes about 20 L.
Paper or mesh tape?
Paper is stronger and the standard for flat joints and corners; self-adhesive mesh is quicker but needs setting compound over it. The length is the same either way.
How many screws?
Every 300 mm along each stud or joist, with studs at 450 mm centres, is about 15 per square metre of board; 600 mm centres need about 11. Add adhesive on the studs to reduce screws and popping.
What about the corners?
Internal corners use tape folded in the crease and count in the tape length; external corners take metal or paper-faced bead sold by the length — measure them separately.
Where these figures come from
- The Engineering ToolBox — material densities, coverage and unit data — bulk densities, concrete at 2,400 kg/m³, board and sheet sizes
- Cement Concrete & Aggregates Australia — concrete basics and yields — bag yields, density 2,400 kg/m³
- Australian Building Codes Board — the National Construction Code
Last checked: September 2026. Coverage rates and material sizes are typical manufacturer figures — check the product you buy.