What grit sequence should I use for floor sanding?

For standard renovation: start at 40 grit, then 60, 80 and finish at 120. For heavily damaged floors, start at 24 grit. For light refinishing, 80 and 120 grit may be sufficient. Never skip more than one grit level.

How many sanding belts do I need?

A drum sander belt typically covers 10–20m² before needing replacement. For a 20m² room with 4 grit passes, expect to use 5–8 drum belts and a similar number of edger discs.

How much lacquer do I need for a wooden floor?

Apply 3 coats of floor lacquer at approximately 0.1 L/m² per coat. For a 20m² room, that’s 6 litres total. Sand lightly with 120 grit between coats. Oil finishes use a similar rate.

What is gap filler for wooden floors?

Gap filler (a mix of resin and fine sanding dust) is used to fill gaps between floorboards before final sanding. Allow approximately 0.05 kg/m² for average gap filling. For very gappy floors, use more.

How long does it take to sand a floor?

A typical 15–20m² room takes 1–2 days for sanding (4 grit passes plus edging), plus drying time between lacquer coats (4–6 hours each). Allow 3–4 days total for the complete process.

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Floor Sanding Calculator — Belts, Discs & Lacquer

Calculate sanding belt and disc count by grit sequence (40/60/80/120), lacquer coats per m\u00b2 and gap filler quantities.

Floor Area

Total area to sand

Grit Sequence

Standard: 40/60/80/120

Lacquer Coats

Standard: 3 coats

Price Per m\u00b2 (optional)

For professional sanding cost estimate

How We Calculate This

This calculator works out the consumables needed for floor sanding based on your floor area and chosen grit sequence.

The formula

Drum belts per grit = Floor area ÷ Belt coverage (m\u00b2)

Edger discs per grit = Edge area (~15%) ÷ Disc coverage

Lacquer (L) = Floor area × 0.1 L/m\u00b2 × Number of coats

Frequently Asked Questions

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Last updated: March 2026

All calculations are estimates. Verify with your supplier.