Wood Pellet Stove Annual Fuel Cost Calculator

Wood pellets deliver about 8,000 BTU per pound, or about 320,000 BTU per 40-pound bag.
Pellet stoves typically run 75-85% efficient, so usable heat is closer to 6,400-6,800 BTU per pound.
The cost math is straight multiplication once you know how many BTU/h your stove pulls and how many hours it runs.

The math:

bags_per_season = (BTU_per_hour × hours_per_day × days_per_season) / 320,000 annual_cost = bags × price_per_bag

A worked example.
Standard 40,000 BTU/h pellet stove, 12 hours/day, 150-day heating season.
Annual BTU: 40,000 × 12 × 150 = 72 million BTU.
Bags: 72M / 320,000 = 225 bags = 4.5 tons.
At $7/bag (typical 2026 retail): $1,575 for the season.
A bulk ton purchased ahead of season is often $260-320 ($6.50-$8 per bag), so the same 4.5 tons could be $1,170-1,440 if bought right.

Pellet stoves rarely run at full output continuously.
Most are sized for the room they heat and modulate down to 25-50% output most of the time.
A more realistic burn rate for whole-day operation is about 2-3 lb/hour for a residential stove, which works out to 0.7-1.0 bags per day.
For a 5-month heating season at 1 bag/day, that is 150 bags = 3 tons = $1,050 at $7/bag.

Comparison to other fuels per million BTU delivered:

• Wood pellets at $260/ton: about $16/MMBTU
• Cordwood at $300/cord (well-seasoned hardwood, 65% efficient stove): about $13/MMBTU
• Natural gas at $1.30/therm (95% efficient furnace): about $14/MMBTU
• Oil at $4.00/gallon (85% efficient): about $34/MMBTU
• Propane at $2.50/gallon (90% efficient): about $30/MMBTU
• Electric resistance at $0.16/kWh: about $47/MMBTU
• Heat pump (COP 3) at $0.16/kWh: about $16/MMBTU

Pellets are competitive with natural gas in the Northeast, much cheaper than oil and propane, and roughly tied with a modern heat pump.
The advantage of pellets is independence from gas lines and less price volatility than oil — the disadvantage is the labor of feeding the stove daily and dealing with bags.

A few practical points.
Premium hardwood pellets burn cleaner and produce less ash than standard softwood pellets, but cost 15-25% more.
For a normal-use stove, the difference is mostly aesthetic; ash cleanout once a week is fine either way.
Pellet quality varies more than people expect — buy from a single mill if you can, since switching brands mid-winter often means re-tuning the stove’s air mix.
And storage is real: 4 tons of pellets needs about 200 cubic feet of dry storage (a typical garage corner), kept off the floor on pallets to prevent moisture damage.

The hidden cost most calculators skip.
A pellet stove uses 100-200 W of electricity continuously to run the auger and exhaust fan.
That is 0.1-0.2 kWh per hour, or about $30-50 per heating season at typical electric rates — small but not zero.
And during a power outage, a standard pellet stove stops working entirely (unlike a wood stove, which keeps burning).
Battery backup or a generator is needed for outage-resilient pellet heat.