Calculator methodology

Cook hours

Each protein has a fixed hours term plus an hours-per-pound term. That sum is scaled toward the usual 225 F smoke:

cookHours = (fixedHours + hoursPerLb × weightLbs) × (225 / targetTempF)^timeExponent

The time exponent is 0.85 for everything except whole turkey and whole chicken, which use 2. Higher set points shorten the clock, but not 1:1 on brisket, pork, or ribs. Collagen and stalls do not care about a clean inverse. Ribs and wings lean on the fixed term because weight hardly moves those cooks.

Whole birds

Published turkey times roughly halve between 225 F and 325 F. A 0.85 curve cannot get there, and our turkey line used to run on it: a 12 lb bird at 325 F came out at 4 hours 15 minutes, and a 20 lb bird at 6 hours 35 minutes. That ran 30 minutes to 2 hours past the Traeger and USDA ranges, and the pellet estimate ran long by about the same share, because pellets follow the hours.

Turkey is now 2.1 hours plus 0.38 hours per pound at 225 F, scaled with the 2 exponent. Whole chicken is 0.5 hours plus 0.75 hours per pound on the same curve. Wings stay on 0.85 with a smaller fixed term of 0.9 hours, since their published times move less with heat. The curve is fit from 225 F up, so below that a turkey or whole chicken is timed as if the pit were at 225 F, and the calculator and planner warn you, because USDA says a smoker should hold 225 to 300 F for poultry. Here is how the calculator lines up with what the grill makers and USDA publish:

• Turkey, 12 lb at 325 F: about 3 hr 12 min. Traeger says 3 to 3.5 hours. USDA's 325 F roasting chart says 2.75 to 3 hours for 8 to 12 lb and 3 to 3.75 hours for 12 to 14 lb.
• Turkey, 20 lb at 325 F: about 4 hr 39 min. Traeger says 4.5 to 4.75 hours. USDA says 4.25 to 4.5 hours for 18 to 20 lb and 4.5 to 5 hours for 20 to 24 lb.
• Turkey, 12 lb at 300 F: about 3 hr 45 min. Traeger's smoked turkey recipe runs a 12 lb bird at 300 F for 3 to 4 hours.
• Turkey, 14 lb at 250 F: about 6 hr 1 min. Butterball's smoker chart, run at about 250 F, gives 6 to 10 hours for 12 to 18 lb.
• Turkey, 12 lb at 225 F: about 6 hr 40 min. Traeger and Pit Boss both use about 30 minutes per pound at 225 F, which is 6 hours. Butterball's electric smoker directions at 225 F say 8 to 12 hours. We sit between the two.
• Whole chicken, 3.25 lb at 225 F: about 2 hr 56 min. Traeger's smoked whole chicken recipe says 2.5 to 3 hours for a 3 to 3.5 lb bird.
• Whole chicken, 3.5 lb at 350 F: about 1 hr 17 min. USDA lists 1.25 to 1.5 hours at 350 F for a 3 to 4 lb broiler-fryer. At 375 F a 4 lb bird comes out at about 1 hr 16 min, against about 70 minutes in Traeger's Chicken Challenge recipe.
• Wings, 4 lb: about 59 min at 225 F, 40 min at 350 F, and 38 min at 375 F. Traeger says about an hour at 225 F and about 35 minutes at 375 F. USDA says 30 to 40 minutes at 350 F, and Pit Boss's wing recipe says 40 minutes at 350 F.

Published numbers disagree, and they are oven or recipe numbers, not lab tests. AmazingRibs runs faster than all of these at 325 F (2 to 2.5 hours for a 12 to 14 lb turkey). All of these times are for unstuffed birds. FSIS says not to stuff a turkey you smoke, because the stuffing can lag behind 165 F, so stuffed timings only apply to roasting at 325 F or above. Treat the estimate as a planning number and pull on a probe, not the clock. Sources:

• Traeger, How long to cook a turkey on a pellet grill
• Traeger, How to brine a turkey (smoke and roast rules of thumb)
• Traeger, Smoked turkey recipe (12 lb at 300 F)
• USDA FSIS, Let's Talk Turkey Roasting
• USDA FSIS, Turkey: Alternate Routes to the Table
• USDA FSIS, Smoking Meat and Poultry
• Pit Boss, Thanksgiving smoked turkey
• Butterball, How to smoke a turkey
• AmazingRibs (Meathead), ultimate BBQ turkey recipe
• Traeger, How to smoke a whole chicken
• Traeger, Chicken Challenge recipe (4 lb at 375 F)
• USDA FSIS, Chicken from Farm to Table
• Traeger, How to grill chicken wings
• Traeger, Smoked chicken wings guide
• Pit Boss, Crispy and easy BBQ chicken wings

Worked turkey examples with pellets, hopper left, and a start time are on turkey on a pellet grill.

Pellet pounds

A model, or the generic profile where you type the rate yourself, starts with an assumed burn rate at 225 F. Default generic is 0.85 lb/hr. Then:

burnLbPerHour = baseBurn × (targetTempF / 225)^1.2 × ambientMultiplier

pelletLbs = 0.35 + cookHours × burnLbPerHour

The 0.35 lb startup pad covers ignition. Leave the lid open and you will beat it.

Ambient multipliers

Mild is 1.0x. Cool is 1.25x. Cold is 1.55x. Winter / sub-freezing is 2.1x.

Those are community-typical ranges, not wind-tunnel data. A cheap gasket in a 20 mph gust can outrun winter. A heavy, tight grill in a garage can undershoot it.

Hopper warning

The calculator also works out how many hours a full hopper actually runs. Take the startup pad off the top, then divide by the burn rate above:

hopperRunHours = (hopperLbs - 0.35) / burnLbPerHour

shortfallHours = cookHours - hopperRunHours, floored at zero

That is the number the warning talks about, because "you are 3 hours short" lands harder than "negative 18 lb." Because burnLbPerHour already carries your target temp and your ambient pick, this runtime moves when those move.

The overnight hours in the grill database are this same formula, run with the set point pinned at 225 F and ambient pinned at mild. Only the inputs differ, so a model's card and the calculator agree: put that model's listed hopper and assumed burn rate into the calculator at 225 F in mild weather and you get the hours on its card. The database holds those two inputs still so models can be compared. The calculator lets you move them, which is what your cook actually does.

Those hours used to skip the 0.35 lb startup pad, so they read long by whatever share of the hopper the pad is: about 2% on an 18 lb hopper, about 4% on an 8 lb one. That was enough to park four models exactly on a filter boundary they had not really earned. The pad is in now and the boundaries are the same 225 F hours the calculator would give you.

If estimated pellets meet or beat hopper size, the cook empties the hopper on paper. A margin under 4 lb, or under 15% of the hopper, counts as thin. A thin margin on a cook of 8 hours or longer is the overnight warning. A thin margin on a shorter cook is the plain refill warning.

Those two rules used to be ranked the other way, which quietly hid the overnight wording on any hopper of roughly 27 lb or more: the 15% rule always fired first on a big hopper, so a 40 lb hopper could never say "overnight." Same thresholds, honest labels now.

What this will not do

It will not tell you when meat is safe. It will not model your exact fire pot, pellet brand, or the neighbor's wind tunnel. It will not invent lab-test burn rates for Traeger, Pit Boss, Recteq, Camp Chef, or Z Grills. Model rates in the grill database are labeled assumptions so the calculator has a starting point.