Polyurethane Calculator

Polyurethane Calculator - Protective Topcoat Quantity Estimator

Polyurethane is the most common protective topcoat for wood furniture, floors, and cabinetry, but coverage rates vary a lot by finish type and application method. This calculator estimates how much you need based on surface area, finish type, coat count, and how you're applying it.

How to Use the Polyurethane Calculator

1. Surface Area: Total area to be finished, in square feet
2. Finish Type: Water-based, oil-based, or polyacrylic
3. Number of Coats: 2, 3, or 4 - three coats is the standard for durable protection
4. Application Method: Brush, roller, or spray

Choosing a Finish Type

Water-based polyurethane dries fast, stays clear (won't amber over time), and cleans up with soap and water, but is slightly less durable than oil-based. Oil-based polyurethane is more durable and self-levels beautifully, but ambers noticeably over time and has a much longer dry time between coats. Polyacrylic is a water-based option formulated to go over light woods and painted or stained finishes without adding any yellow tint.

Brush application typically covers 125-150 square feet per quart per coat; spraying uses noticeably more material due to overspray but gives the smoothest finish. Lightly sand between coats with fine 320-400 grit sandpaper to knock down dust nibs and help the next coat bond.

Related Tools

• Wood Stain Calculator - Plan the stain coat underneath your topcoat
• Paint Calculator - Compare with a painted finish instead