Filler and Putty Calculator
Calculate kg of filler to smooth walls.
The Filler and Putty Calculator is a free tool designed for construction professionals and enthusiasts. Calculate kg of filler to smooth walls. Instantly get the required materials broken down by purchase units, with an option to add a wastage allowance so you never run short on site.
Inputs
Result
Result
How to Use This Calculator
- Measure the surface to paint in m² (length × height of each wall/ceiling).
- Subtract door and window areas (approx. 1.8 m² per door, 1.2 m² per window).
- Enter the number of coats: 1 coat for same-colour refresh, 2–3 for colour change.
- Check the paint spread rate on the product data sheet (typical: 10–14 m²/L).
- Click 'Calculate' to see net litres, total litres with wastage and cans to buy.
Frequently Asked Questions
For walls in good condition with the same colour: 1 coat. For colour change or highly absorbent walls: 2 coats. For dark over light or vice versa: 2–3 coats + primer.
Interior emulsion typically covers 12–14 m²/L per coat. Exterior or textured paint covers less, around 8–10 m²/L.
Measure length × width of the ceiling in metres. Apply the paint coverage (10–14 m²/L) and number of coats. For textured ceilings, use 20 % more paint.