Estimate how long your firewood needs to dry. Factor in wood species, climate, and stacking method to reach the ideal 20% moisture content. Accurate drying time estimates prevent the frustration and safety risks of trying to burn unseasoned fuel during the winter.
Choose the wood species, enter the starting and target moisture content, and select how the stack is stored. The calculator divides the moisture you need to shed by a monthly drying rate and rounds up to whole months. Storage sets the base rate: covered splits dry fastest at 5 percentage points per month, open splits at 4, covered rounds at 3, and uncovered rounds at just 2.
A species factor then scales that rate. Light, porous White Pine dries 20% faster than baseline (factor 1.2); Sugar Maple is 0.9, Red Oak 0.85, White Oak 0.8, and dense Hickory the slowest at 0.75. Taking green White Oak from 45% down to 20% moisture as covered splits is 25 points ÷ (5 × 0.8) = 6.25, rounded up to 7 months; White Pine under identical storage needs only 5.
The verdict bands the answer: up to 6 months reads as fast, 7–12 as moderate, and over a year as long. The extremes sit far apart — Red Oak left as uncovered rounds dries at only 2 × 0.85 = 1.7 points per month, stretching the same 25-point drop to 15 months. In this model, splitting the wood and topping the stack with a cover are the two levers that move the timeline most.
Storage type alone spans a 2.5× range in this model. Splitting exposes the wet interior grain, so split stacks carry base rates of 4–5 percentage points of moisture per month versus 2–3 for unsplit rounds. Combined with a top cover that sheds rain, a covered split stack at 5 points per month finishes the same drying job in well under half the time of uncovered rounds at 2.
Of the five modeled species, White Pine is quickest at factor 1.2 and Hickory slowest at 0.75, with White Oak (0.8), Red Oak (0.85), and Sugar Maple (0.9) in between. As covered splits dropping from 45% to 20% moisture, that spread means 5 months for White Pine but 7 months for either Hickory or White Oak. Density is the reason: tighter grain holds its water deeper in the wood.
It is a linear model: constant points-per-month rates rounded up to the next whole month, which is why the result is always an integer. Real drying is front-loaded — wood sheds surface moisture quickly and slows as it approaches equilibrium with local humidity — and warm, dry seasons do most of the work. The figure is a planning baseline for comparing species and storage choices, and the calculator returns no result at all if the target moisture is not below the starting value.