When do I need grain filler?

Open-grain woods like oak, ash, and walnut benefit from grain filling before applying a smooth film finish like lacquer or French polish. The filler fills the pores so the final finish is perfectly smooth and level.

How much wood filler do I need?

For grain filling, approximately 150g per m². For repairs (filling cracks and holes), about 300g per m² depending on damage. For skim coating, about 200g per m².

What type of wood filler should I use?

For grain filling before finishing, use a proprietary grain filler or thinned epoxy. For structural repairs, use two-part epoxy filler. For cosmetic repairs before painting, standard interior wood filler is fine.

WoodCalcs

Wood Filler Calculator — Grain Fill and Repair

Estimate wood filler quantities for grain filling and repairs.

Surface Area

Fill Type

Price per kg (optional)

How We Calculate This

Filler (kg) = Surface area (m²) × Application rate (kg/m²)

Grain filling: ~0.15 kg/m². Repairs: ~0.3 kg/m². Skim coat: ~0.2 kg/m².

Frequently Asked Questions

Related Calculators

Wood Stain Calculator

Calculate how much wood stain you need based on surface area and coats.

Varnish Coverage Calculator

Work out varnish quantities for floors, furniture, and woodwork.

Paint Coverage Calculator

Calculate paint quantities for wood surfaces including primer coats.

Oil Finish Calculator

Estimate oil quantities for Danish oil, tung oil, and linseed finishes.

Wax Coverage Calculator

Calculate wax quantities for furniture and wood surface finishing.

Last updated: February 2026

All calculations are estimates. Always verify measurements and material quantities before cutting or purchasing.