Cord Calc / Pellet stoves
UMD Extension · 2 maker spec pages · checked 2026-10-21
Tons of pellets a winter
Wood pellets hold about 8,250 Btu per pound, says the University of Maryland Extension, or 16.5 million Btu a ton. Through the Osburn 2500 pellet stove's published 70.3% efficiency, the example house (2,000 sq ft, built in the 1970s) burns about 5.0 tons in a normal winter in Oregon, the median state, against 3.9 cords of wood.
- 1Pellet energy (UMD) 8,250 Btu/lb
- 2Per ton 16.5 million Btu
- 3Oregon, example house 5.0 tons a winter
- 4Osburn 2500 pellet stove 70.3% HHV
Pellet energy, from the extension sheet
UMD's fact sheet FS-937 puts it plainly: "Most pellets have 5-10% moisture content and a heating value of approximately 8,250 Btu/lb." and "Once wood is densified, it will all have the same Btu content." Unlike cordwood, where heat per cord runs from the softest to the densest species over a wide range (see the firewood BTU chart), one pellet figure serves for all. At 2,000 pounds a ton that is 16.5 million Btu per ton. Maine's state fuel survey is consistent with it: its $357 a ton and $21.64 per million Btu imply 16.5 million Btu per ton. UMD also grades pellets by ash: premium below 1%, standard 1 to 3%, with no more than 0.5% dust, and says stored pellets last about a year.
Pellet stoves with published ratings
| Stove | Area | Heat output | Efficiency | g/h | Hopper | Burn rate |
|---|---|---|---|---|---|---|
| Osburn 2500 pellet stove Listed on the maker's current pellet stove page | 500–2,000 sq ft | 6,648–28,540 BTU/h | 70.3% HHV, 75.8% LHV | 0.96 | 60 lb | 1.2–4.7 lb/h |
| Drolet ECO-65R Listed as discontinued on the maker's page | 800–2,600 sq ft | 6,966–28,526 BTU/h | 84.4% optimum (basis not labelled; no average efficiency published) | 0.77 | 125 lb | 1.12–4.63 lb/h |
Pellet stoves as published on each maker's product page. Makers state output two ways: a maximum heat input rate (pellet energy burned per hour) and an overall heat output range (heat delivered). Both are shown, never mixed. Maximum heat input: Osburn 2500 pellet stove 39,260 BTU/h (maximum heat input rate (maximum burn rate, dry pellet energy 8,600 BTU/lb)); Drolet ECO-65R 50,800 BTU/h (maximum heat input rate (basis not stated)). Checked 2026-10-21.
The two stoves deliver almost the same heat at full burn, about 28,540 BTU/h, although Drolet rates its stove for up to 2,600 sq ft and Osburn for 2,000. Only Osburn publishes an average efficiency, 70.3% on the higher heating value, so that figure is used for the tons below. At its top burn rate of 4.7 lb an hour the 60-lb hopper lasts about 12.8 hours, and Osburn prints a maximum burn time of 51 hours. Both maker pages say "EPA 2020 approved"; the EPA rules guide explains the limits.
Pellets against cordwood, by state
| State | Degree days | Pellets, tons | 40-lb bags | Cords (74% stove) |
|---|---|---|---|---|
| North Dakota | 9,184 | 8.8 | 439 | 6.9 |
| Montana | 8,550 | 8.2 | 409 | 6.4 |
| Minnesota | 8,534 | 8.2 | 408 | 6.4 |
| Wyoming | 8,225 | 7.9 | 393 | 6.2 |
| Vermont | 8,058 | 7.7 | 385 | 6.0 |
| Maine | 7,758 | 7.4 | 371 | 5.8 |
| South Dakota | 7,633 | 7.3 | 365 | 5.7 |
| Wisconsin | 7,529 | 7.2 | 360 | 5.6 |
| New Hampshire | 7,449 | 7.1 | 356 | 5.6 |
| Colorado | 7,053 | 6.7 | 337 | 5.3 |
| Utah | 6,979 | 6.7 | 334 | 5.2 |
| Idaho | 6,870 | 6.6 | 329 | 5.2 |
| Iowa | 6,822 | 6.5 | 326 | 5.1 |
| Michigan | 6,745 | 6.5 | 323 | 5.1 |
| Nebraska | 6,281 | 6.0 | 300 | 4.7 |
| Massachusetts | 6,132 | 5.9 | 293 | 4.6 |
| Illinois | 6,105 | 5.8 | 292 | 4.6 |
| New York | 6,001 | 5.7 | 287 | 4.5 |
| Connecticut | 5,849 | 5.6 | 280 | 4.4 |
| Rhode Island | 5,761 | 5.5 | 276 | 4.3 |
| Pennsylvania | 5,701 | 5.5 | 273 | 4.3 |
| Ohio | 5,689 | 5.4 | 272 | 4.3 |
| Indiana | 5,628 | 5.4 | 269 | 4.2 |
| Washington | 5,610 | 5.4 | 268 | 4.2 |
| Oregon | 5,269 | 5.0 | 252 | 3.9 |
| New Jersey | 5,168 | 4.9 | 247 | 3.9 |
| West Virginia | 5,067 | 4.8 | 242 | 3.8 |
| Missouri | 4,980 | 4.8 | 238 | 3.7 |
| Kansas | 4,876 | 4.7 | 233 | 3.7 |
| Maryland | 4,563 | 4.4 | 218 | 3.4 |
| Delaware | 4,483 | 4.3 | 214 | 3.4 |
| New Mexico | 4,462 | 4.3 | 213 | 3.3 |
| Kentucky | 4,397 | 4.2 | 210 | 3.3 |
| Virginia | 4,259 | 4.1 | 204 | 3.2 |
| Tennessee | 3,754 | 3.6 | 180 | 2.8 |
| Oklahoma | 3,535 | 3.4 | 169 | 2.7 |
| Nevada | 3,452 | 3.3 | 165 | 2.6 |
| Arkansas | 3,391 | 3.2 | 162 | 2.5 |
| North Carolina | 3,359 | 3.2 | 161 | 2.5 |
| California | 2,814 | 2.7 | 135 | 2.1 |
| Georgia | 2,807 | 2.7 | 134 | 2.1 |
| Alabama | 2,669 | 2.6 | 128 | 2.0 |
| South Carolina | 2,587 | 2.5 | 124 | 1.9 |
| Mississippi | 2,389 | 2.3 | 114 | 1.8 |
| Arizona | 1,919 | 1.8 | 92 | 1.4 |
| Texas | 1,818 | 1.7 | 87 | 1.4 |
| Louisiana | 1,654 | 1.6 | 79 | 1.2 |
| Florida | 646 | 0.6 | 31 | 0.5 |
Same house and heat model as every state page (methodology); tons = heat ÷ (8,250 Btu/lb × 2,000 × 70.3%). Cords use 20 million Btu a cord and the 74% median stove efficiency. Coldest: North Dakota, 8.8 tons; mildest: Florida, 0.6 tons.
What a winter of pellets costs where a state publishes a price
Maine's Governor's Energy Office priced pellets at $357 a ton on September 28, 2026 (Maine-produced pellets in 40 lb bags, local delivery). The example house in Maine burns 7.4 tons, about $2,649 a winter, against $2,065 for 5.8 cords at Maine's $355 a cord. Per million Btu delivered into the house that is $30.78 for pellets at 70.3% and $21.81 for cordwood at 74%. New Hampshire's Department of Energy lists bagged wood at $380 a ton ($7.93 a bag) as of July 1, 2024; its notes say pellets come in 40-pound bags and that bagged prices do not include delivery, so it is not directly comparable with Maine's delivered price. No other state agency price was found.
The price per ton is not the whole cost: pellet stoves need electricity for the auger and fans, and pellets need a dry store. The wood versus pellet cost guide lays out Maine's figures side by side, and the stove size chart covers wood stoves by floor area. Work out your cords instead