How much polyurethane do I need for a table top?

Less than most people buy. A typical dining tabletop is 30 to 40 sq ft counting both faces and the edges, and three coats of oil-based polyurethane at around 500 sq ft per gallon use roughly a quart. Enter your table above for the exact figure.

How much finish do I need for kitchen cabinets?

Count every door and drawer front, both faces and edges, plus the face frames and cabinet sides you will finish. Twenty average doors come to around 120 to 140 sq ft, which at three coats of water-based polyurethane is about a gallon.

How far does a quart of Danish oil go?

Check your can. Many oil finish labels claim roughly 150 sq ft or more per quart for each coat on smooth, sanded wood, and less on open grain or end grain. Oils soak in, so the first coat uses noticeably more than later ones.

Why does the first coat use more finish?

Bare wood absorbs the first coat into its pores, especially open-grained species like oak and ash. Once sealed, later coats sit on the surface and spread further. That is why the tool adds extra to the first coat only.

Wood finish calculator

Describe the piece, not its square footage. The tool counts every face and edge, then tells you how much polyurethane or oil to buy and how much each coat takes.

Enter your project

What are you finishing?

Length (in)

Width (in)

Thickness (in)

Finish the underside too (recommended: it slows moisture moving in and out evenly on both faces)

Finish

Coverage per coat (sq ft per gallon) from your can

Coats

Extra soaked up by the first coat (%)

Extra allowance (%)

How it is calculated

Surface area. Most people do not know the area of a bookcase, so the tool builds it from the piece. A tabletop is its top, plus the underside if you finish it, plus the edges (perimeter x thickness). A bookcase counts both faces of both sides, the top, the bottom and every shelf, plus the inside of the back if you include it. A door counts both faces and its four edges.

Finish. Each coat covers the area at the rate on your can, in square feet per gallon. Bare wood soaks up more on the first coat, so the first coat gets your extra percentage (25 percent by default). Later coats go onto sealed wood and cover at the full rate. Then your allowance is added for brushes, rags and the bit left in the can.

Cans. The total is rounded up to whole pints, and the tool picks the fewest cans that cover it: gallons (128 fl oz), quarts (32 fl oz) and pints (16 fl oz). Pre-filled coverage figures are typical label values; the number on your can wins.

Worked example

A 60 x 36 in tabletop, 1.5 in thick, finished top and bottom: 2,160 + 2,160 sq in of faces plus 288 sq in of edges = 32 sq ft.

Three coats of oil-based polyurethane at 500 sq ft per gallon, with 25 percent extra on the first coat and a 10 percent allowance: the first coat takes 11.3 fl oz, each later coat 9.0 fl oz, 29.3 fl oz in total (0.87 L). Buy 1 quart.

Oil finishes can make rags heat up and catch fire as they dry. Lay used rags flat outdoors to dry, or keep them in a sealed metal can of water. Ventilate while finishing and follow the can's safety directions.

Common questions

How much polyurethane do I need for a table top?: Less than most people buy. A typical dining tabletop is 30 to 40 sq ft counting both faces and the edges, and three coats of oil-based polyurethane at around 500 sq ft per gallon use roughly a quart. Enter your table above for the exact figure.
How much finish do I need for kitchen cabinets?: Count every door and drawer front, both faces and edges, plus the face frames and cabinet sides you will finish. Twenty average doors come to around 120 to 140 sq ft, which at three coats of water-based polyurethane is about a gallon.
How far does a quart of Danish oil go?: Check your can. Many oil finish labels claim roughly 150 sq ft or more per quart for each coat on smooth, sanded wood, and less on open grain or end grain. Oils soak in, so the first coat uses noticeably more than later ones.
Why does the first coat use more finish?: Bare wood absorbs the first coat into its pores, especially open-grained species like oak and ash. Once sealed, later coats sit on the surface and spread further. That is why the tool adds extra to the first coat only.

Related tools and guides

WoodworkingCalc results are careful estimates. Products differ, so use the coverage, mix ratio and maximum pour depth printed on your own product label, and check the numbers against your project before you mix or buy.