Stack: Firewood & BTU Calc

What it does

Stack is the firewood calculator for wood-stove and fireplace owners. Measure a stacked pile and get cords — a cord is 128 cubic feet per NIST Handbook 130 — plus what you really paid per full cord, so a short load or a vague "face cord" can't fool you. The cord & stack calculator, the complete 44-species BTU chart, and the Burn Safe reference are free forever at full citation quality.

Stack is honest by design: time-based seasoning charts are folklore, so elapsed time is shown as a planning estimate against the EPA six-month floor, and a stack is marked ready to burn only when your own moisture-meter reading on a freshly split face comes in under the EPA 20% target. Sources include USU Forestry Extension, US EPA Burn Wise, the CSIA, NIST, and the US EIA — named next to every number.

Stack Pro — one-time unlock

$6.99, once. The seasoning tracker (every stack you split: species, time, moisture log), the winter planner (last winter's oil, gas, propane, or electric usage → the cords you actually need), the wood-vs-other-fuels comparison (everything in dollars per million BTU of delivered heat, the US EIA method), and per-species value pricing. No subscription, no ads, no account.

Common questions

How many cords do I need for winter? The winter planner converts last season's fuel bill into delivered heat and back into cords of your species at your stove's efficiency — a number you can buy and split against, with margin advice.

Is wood heat actually cheaper? Fuels sell in different units, so Stack normalizes everything — $/cord, $/gallon, $/therm, ¢/kWh — into dollars per million BTU of heat delivered into the room. Sometimes wood wins big; sometimes it doesn't. The math tells you.

Why creosote matters: burning unseasoned wood keeps flue gases cool, which condenses creosote on the chimney walls — and per the CSIA, about an eighth of an inch of buildup is a chimney-fire hazard. Dry wood isn't just better heat; it's the safety play.

Privacy

Stack collects nothing. No analytics, no accounts, no cloud — your stacks and readings live on your device. Privacy policy · Support