Finish quantity calculator
Read the product label first
Enter the selected finish’s documented coverage for this surface and coat. Separate surfaces or coats with different coverage need separate calculations.
Quantity worksheet
Enter measured area and the product’s coverage to begin.
Check the coverage basis before buying finish
The calculator supports a purchase estimate once the treatment area and the selected product's application basis are known. A quantity estimate does not determine whether an existing surface is ready for treatment or whether a product is appropriate for it.
Use the coverage statement for the actual application
Record the product, its current instructions, coverage units and coat requirements. Confirm whether the stated coverage applies to one coat or the complete system before multiplying. Keep a test area's consumption record separate from an unverified assumption.
Measure the surfaces being treated
Separate the walking surface from fascia, steps, rail components and other faces. Deduct only areas that will genuinely remain untreated. Packaging, unused remainder and application losses belong in the purchase record, not in the measured deck area.
Hypothetical coverage arithmetic
For one coat over 400 square feet at an assumed 200 square feet per gallon, the arithmetic is 2 gallons before any separately stated allowance or package rounding. Those figures teach the calculation; use the chosen finish's documented coverage and application instructions for a real deck.