The calculation is based on the total surface area of the end grain you need to cover.

1. Select Calculation Mode: Choose whether you are sealing the ends of round logs or rectangular boards.
2. Calculate End Grain Area:
   - For logs, the area of one end is `π × (Diameter / 2)²`.
   - For boards, the area of one end is `Width × Height`.
3. Calculate Total Area: The calculator multiplies the area of one end by 2 (for both ends) and then by the total number of logs or boards. This gives the total area in square inches.
4. Determine Sealer Amount: The total area is converted to square feet and then divided by the sealer's coverage rate (typically 100 sq. ft. per gallon) to find the required number of gallons.

• End Grain: The surface of wood exposed when it is cut perpendicular to the direction of the wood fibers (the grain).
• Checking: The separation of wood fibers, creating cracks or splits, caused by stresses from uneven or rapid drying.
• Wax Emulsion: The most common type of end sealer, where wax particles are suspended in water. As the water evaporates, it leaves a thick, protective wax coating.
• Green Wood: Freshly cut wood that has not yet been dried and has a high moisture content.
• Turning Blank: A piece of green wood, sealed on the ends, intended to be turned on a lathe.

"Don't be shy with the application. You want a thick, milky-white coating that completely obscures the end grain. A thin coat won't provide an effective moisture barrier. It should look like a thick layer of latex paint. Apply it with a cheap chip brush and just throw the brush away when you're done." - Sawmill Operator

"The sooner you can get the sealer on after cutting, the better. I try to seal the ends of a log within minutes of the chainsaw stopping. Every minute you wait, especially on a hot, windy day, is a minute that checks have a chance to start forming."

Example 1: Sealing a Pile of Logs for Firewood
You have 20 logs, each with an average diameter of 12 inches.
Area per end: `3.14 * (12/2)² = 113` sq. in.
Total Area: `113 * 2 ends * 20 logs = 4520` sq. in. (or 31.4 sq. ft.).
Sealer Needed: `31.4 / 100 = 0.31` gallons, or about 1.25 quarts.

Example 2: Preparing Bowl Turning Blanks
You have cut 30 bowl blanks, each roughly 8" wide by 3" thick.
Area per end: `8" * 3" = 24` sq. in.
Total Area: `24 * 2 ends * 30 blanks = 1440` sq. in. (or 10 sq. ft.).
Sealer Needed: `10 / 100 = 0.1` gallons, or less than half a quart.

• Waiting Too Long to Apply: Applying sealer to wood that has already started checking will not fix the checks. It must be applied to fresh, green wood.
• Applying Too Thinly: A translucent or watery coat is not enough. The coating should be thick and opaque.
• Using Latex Paint: While better than nothing, standard latex paint is not as effective as a purpose-made wax emulsion sealer. It doesn't build as thick a film and can be more brittle.
• Forgetting to Seal Both Ends: Moisture will escape from any exposed end grain, so be sure to coat both ends of every log and board.

• Sawyers & Mill Operators: Sealing the ends of freshly milled slabs and lumber to maximize quality and saleable yield.
• Woodturners: Preserving green wood turning blanks for bowls and spindles, allowing them to dry slowly.
• Firewood Processors: Sealing the ends of high-quality firewood logs (like oak or hickory) to sell as seasoned, crack-free wood.
• Lumber Storage: Protecting the ends of stacked lumber that is air-drying.