How much finish do I need? A coverage calculator
Surface area from your part sizes, times coats, divided by the coverage printed on the can. Liters or gallons, so you buy one can and not three.
Cans print a coverage number and I never know how it turns into “buy this size”. Type the size of the piece, the coats, and the coverage from the label. I did not put a default coverage on purpose: it changes with every product.
Everything is calculated in your browser. Nothing is saved or sent.
How it works
Area = length × width for each face you finish, plus the edges if you count them (perimeter × thickness). Finish needed = area × coats ÷ coverage. That is all the math.
The coverage on the label is the maker's number for their method of application. Wiped oils, open-grained woods and a first coat on bare wood may use more or less. I have not measured it, so add the margin you trust.
Common questions
Where is the coverage on the can?
Usually on the back label or the technical data sheet, as square feet per gallon or square meters per liter. If it is not there, the maker's website usually has the data sheet.
Should I count both faces of a tabletop?
Only if you finish the underside too. That is your call; the calculator just multiplies what you give it.