Estimate pellet stove running cost from pellet use, bag price, run time, and startup plus running electricity.
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Table of contents
How to use our Pellet Stove Running Cost Calculator
- Choose how you want to estimate pellet use: use Average heat delivered if you know BTU per hour, or use Pellet use if you track bags per week.
- Enter Run time, Heating season length, and Pellet bag price using your normal heating pattern and the price you actually pay.
- Open Advanced options if you want to change Stove efficiency, Pellet heat content, Bag weight, Electricity price, Power while running, Startup power, or Startup time.
- Click Calculate and read Total running cost for the season first, then compare Pellet fuel cost for the season with Electricity cost for the season.
- Sanity-check the result by comparing Pellet bags needed for the season with what you can store or what you bought last year.
Definitions
BTU: A British thermal unit, a small unit of heat energy. In this calculator, Average heat delivered uses BTU per hour.
kWh: A kilowatt-hour, the amount of electricity used by 1,000 watts running for 1 hour [1]. Electricity price is entered as $ per kWh.
Watts: A measure of electric power. Startup power and Power while running are entered in watts.
Stove efficiency: The percent of pellet heat that becomes useful heat in the room. A 75 percent entry means 75 of every 100 heat units are counted as delivered heat.
Pellet heat content: The heat stored in one pound of pellets, entered as BTU per pound.
Pellet bags needed for the season: The estimated number of bags burned across the Heating season length.
Common mistakes and quick fixes
Mistake: Using the stove's maximum rating for Average heat delivered when it usually runs lower.
Fix: Enter the average BTU per hour the stove delivers while running, or switch to Pellet use if you know bags per week.
Mistake: Entering a full year in Heating season length when the stove only runs during colder months.
Fix: Use the number of days you expect to burn pellets, such as only the main heating season.
Mistake: Leaving delivery, tax, or bulk fees out of Pellet bag price.
Fix: Use the real $ per bag you pay after normal fees are included.
Mistake: Mixing Bag weight with a Pellet bag price for a different bag size.
Fix: Make Bag weight match the same bag used for Pellet bag price.
Mistake: Treating Power while running as the same as Startup power.
Fix: Use Startup power only for ignition time, and use Power while running for the fan, auger, and controls after startup.
Mistake: Reading Total running cost for the season as a guaranteed utility bill.
Fix: Use Electricity cost for the season and Pellet fuel cost for the season as estimates based on the inputs you entered.
Limitations & Key Assumptions / Boundary Conditions
- The BTU method assumes Average heat delivered is a steady average while the stove is running. Real stoves cycle up and down.
- Stove efficiency, Pellet heat content, and Bag weight are editable assumptions. Small changes can move Pellet bags needed for the season.
- The bags-per-week method uses your observed Pellet use directly, so it does not use Average heat delivered, Stove efficiency, or Pellet heat content.
- Electricity cost is based on one Electricity price for the whole season. Tiered rates, time-of-use rates, standby power, and blower speed changes can make the real bill differ.
- Total running cost for the season does not include stove purchase price, installation, maintenance, chimney cleaning, repairs, ash disposal, or storage costs.
- Total running cost for a 30-day month is a simple 30-day average, not a prediction for a specific calendar month.
Methodology
Pellet use from heat output
In heat output mode, the calculator estimates daily pellet pounds from useful heat, run time, stove efficiency, and pellet heat content. Efficiency is entered as a percent, so 75 means 0.75 in the formula.
pellet_lb_per_day = heat_output_btu_per_hr * hours_per_day / ((stove_efficiency_percent / 100) * pellet_btu_per_lb)
pellet_bags_per_day = pellet_lb_per_day / bag_weight_lb
Pellet use from bags per week
In bags-per-week mode, the calculator uses your observed pellet use and converts it to a daily rate.
pellet_bags_per_day = bags_per_week / 7
Pellet cost
Pellet fuel cost is the daily bag estimate times Pellet bag price, then scaled to the heating season.
pellet_cost_per_day = pellet_bags_per_day * pellet_bag_price
pellet_fuel_cost_per_season = pellet_cost_per_day * season_days
Electricity cost
Electricity use is split into steady running power and startup power. The calculator converts watts to kilowatts by dividing by 1000 and converts startup minutes to hours by dividing by 60. This follows the standard relationship between watts, kilowatts, and kilowatt-hours [1].
steady_kwh_per_day = steady_watts * hours_per_day / 1000
startup_kwh_per_day = startup_watts * startup_minutes_per_day / 60 / 1000
steady_electricity_cost_per_season = steady_kwh_per_day * electricity_rate_per_kwh * season_days
startup_electricity_cost_per_season = startup_kwh_per_day * electricity_rate_per_kwh * season_days
electricity_cost_per_season = steady_electricity_cost_per_season + startup_electricity_cost_per_season
Time breakdowns
The calculator adds pellet fuel and electricity, then reports the same average cost by season, day, 30-day month, and operating hour.
total_cost_per_day = pellet_cost_per_day + electricity_cost_per_day
total_running_cost_per_season = total_cost_per_day * season_days
cost_per_operating_hour = total_cost_per_day / hours_per_day
total_cost_per_30_day_month = total_cost_per_day * 30
Mini-example
If Average heat delivered is 20,000 BTU per hour, Run time is 8 hours per day, Stove efficiency is 75 percent, Pellet heat content is 8,200 BTU per pound, Bag weight is 40 pounds, Pellet bag price is $7.50, and Heating season length is 120 days, the pellet estimate is about 78.05 bags for the season. With Electricity price at $0.18 per kWh, Power while running at 100 watts, Startup power at 300 watts, and Startup time at 15 minutes per day, electricity adds $18.90. Total running cost for the season is about $604.27.