Fuel for Winter
The answer
Formula
~1 firewood per home per month (doubles in winter); a kiln doubles fuel per log.
Fuel is the quieter half of the winter problem. Food shortages announce themselves; a fuel shortage looks fine right up until the month the homes stop being heated, and by then the collection season is over. This calculator sizes the woodpile against the same October deadline the food stockpile works to.
The consumption figure
Plan on roughly one firewood per home per month, doubling in winter. The tool multiplies homes by months at the baseline rate. For a safe winter number, use the winter months in the input and treat the result as a floor, not a target.
Fuel is one of the few resources where over-banking costs almost nothing. It does not spoil. It stores under any roof, and idle hands in winter have nothing better to do than cut next year's timber. Keep a two-to-five month buffer at all times and the system stops being something you monitor.
The charcoal loop is the real answer
The highest-leverage building in the fuel economy is the charcoal kiln, because one firewood becomes two charcoal. Fuel per log felled doubles outright. The same logging camp supports twice the homes it otherwise would.
The chain runs logging camp → woodcutter → charcoal kiln. The calculator reports both figures: the raw firewood needed, and the smaller number of logs that covers it once a kiln is in the loop. If your fuel number looks impossible, a kiln is almost always cheaper than a second logging camp.
Where fuel and everything else meet
Charcoal is not only a heating fuel. It is also what the bloomery wants for smelting iron. Scale charcoal for winter and you have usually solved the fuel side of your weapons chain without planning to.
Felling forest has a second-order benefit. Cleared forest becomes meadow, and a region's meadow percentage raises crop, orchard, garden and apiary yields. Cutting timber is not purely extractive. Done in the right places it is a farming improvement, and free lunches are rare here.
One caution in the other direction. Do not let a forest region be logged flat around a settlement that depends on pig farming. The forest-mastery pig bonus scales directly and uncapped with the region's forest cover.
Three buildings, three different jobs
The fuel chain is short, but the roles are easy to confuse. Getting them wrong is the usual reason a settlement with plenty of forest still runs cold. The logging camp fells trees into timber: construction material, not fuel. The woodcutter's lodge turns timber into firewood, which is what homes actually burn. The charcoal kiln then doubles that firewood into charcoal. Placing a logging camp and assuming the houses are warm is the most common version of this mistake.
Storage matters more here than it looks. Goods left on the ground rot in bad weather, and a woodpile is exactly the sort of thing that accumulates outdoors while nobody is watching it. Storehouses take firewood and charcoal; build them early, build them near the consumers, and the buffer you calculated above will still be there in February.
A worked example
Twelve homes through a six-month winter, at the doubled winter rate, is 144 firewood. Route it through a kiln and the same winter costs 72 logs. One logging camp with a woodcutter and a single kiln covers that comfortably. The opening build order can therefore leave the firewood collector until autumn. The chain is cheap, just not instant.
The failure case is the settlement that grows from twelve homes to twenty over the summer without touching the fuel chain. Consumption scales with homes and nothing warns you, so re-run this number every time you add a row of plots rather than once a year.
The Charcoal Loop
