How long a full hopper of pellets lasts

People ask three different questions and get one mushy answer. How long a bag lasts is a shopping question. Whether the fire dies at 3 a.m. is an overnight-failure question. How long a full hopper lasts is the planning number in the middle: hopper pounds divided by burn rate, with a small startup pad taken off the top.

PelletDeck's calculator reports that hopper-run figure on every estimate. The grill database shows the same math in the overnight column, pinned at 225 F in mild weather so models line up. Neither number is a lab overnight test. Wind and a leaky lid still move it.

The formula is shorter than the forum thread

Hopper run hours are (hopper pounds minus 0.35 lb startup) divided by the burn rate at your set point and weather. Mild weather on the generic 0.85 lb/hr seed is the easy case. Winter / sub-freezing is 2.1x that seed. Set point scales burn by (target temp / 225)^1.2. The exact exponents sit on the methodology page.

• 18 lb hopper, mild 225 F, 0.85 lb/hr: about 20 hours 46 minutes. Open a 12 lb brisket at 225 F on the generic seed. The cook wants about 14.4 lb. The hopper still gets the overnight warning because you finish with only a few pounds left.
• Same 18 lb hopper in winter at 1.78 lb/hr: about 9 hours 53 minutes. Same packer with the winter toggle wants about 29.8 lb. The hopper is empty long before morning.

Nothing changed except the weather setting. That is the whole point of cold-weather burn. The controller still says 225 F. The fire is also heating the air that keeps leaking out.

Same hopper size, different barrels

Listed hopper pounds are not interchangeable across models. The grill list stores an assumed burn at 225 F for each row. Those burns are planning assumptions, not manufacturer lab scores. Mild-weather hopper hours land like this:

• Traeger Ranger, 8 lb hopper, 0.55 lb/hr: about 13 hours 55 minutes. Small grill, small tank.
• Traeger Pro 575, 18 lb hopper, 0.90 lb/hr: about 19 hours 37 minutes. A 12 lb brisket on a Pro 575 is about 15.2 lb of pellets and still sits on the overnight warning.
• Traeger Pro 780, same 18 lb hopper, 1.05 lb/hr: about 16 hours 49 minutes. More steel, same tank. Same packer on a Pro 780 wants about 17.7 lb.
• Traeger Timberline XL, 24 lb hopper, 1.15 lb/hr: about 20 hours 34 minutes. Bigger hopper, hotter assumed burn, similar overnight clock to a mild generic 18 lb tank.
• Recteq RT-700, 40 lb hopper, 0.80 lb/hr: about 49 hours 34 minutes. Legacy / discontinued name, still the overnight hopper people cite. Successor naming moved toward Flagship. Same packer on an RT-700 is about 13.6 lb with a lot left over.

Filter the database when you are shopping the sleep question, not the grate question: models whose listed hopper and assumed burn cover 24 or more hours at 225 F, or the 20-hour and longer overnight column, or just 30 lb and larger hoppers.

Hot cooks shrink the hopper clock

A short hot cook does not empty the hopper the way a packer does, but the hours-of-fire number drops hard because burn rate rises with set point.

• Wings at 450 F on a Pro 575: about 2.07 lb/hr once running. That 18 lb hopper runs about 8 hours 32 minutes at that rate. The cook itself only wants about 2.1 lb because it is over in under an hour.

So hopper hours are a fuel-clock, not a cook-clock. Use them to plan sleep and refills. Use a probe for doneness, and read the food-safety disclaimer.

Bag hours and empty-hopper overnight are neighbors, not synonyms

How long a bag of pellets lasts divides bag weight by burn rate. Useful for shopping. Useless at 3 a.m. if the hopper only holds 18 lb.

Empty hopper overnight is the failure mode: cook hours longer than hopper hours, or a thin margin on a long cook. The calculator flags those cases. This page is the plain hopper-hours number those warnings are built from.

If you want the ugly winter version on a mid-size Traeger, run a 14 lb brisket on a Pro 575 in winter. On paper that is about 36.3 lb of pellets and a hopper that only runs about 9 hours 20 minutes. The bag in the garage does not climb into the hopper by itself.