How Long to Smoke a 12 lb Brisket

A 12 lb brisket takes 9 h to 15 h at 250°F. Plan for 12 h 35 m; to serve at 6 pm, light the smoker by 2:45 am.

12 lb brisket at 250°F
9 h – 15 h
plan for 12 h 35 m · rest 60+ min · 5.5–8.3 lb cooked

12 lb brisket at every pit temperature

PitRangePlanvs 250°F
225°F15 h – 21 h18 h 35 m6 h slower
250°F9 h – 15 h12 h 35 m—
275°F7 h 10 m – 12 h10 h 05 m2 h 30 m faster
300°F6 h – 10 h 10 m8 h 30 m4 h 05 m faster

Timeline to serve at 6 pm

StepTime
Light the smoker2:45 am
Meat on (after about 45 min of preheat)about 45 min later
Stall near 155°F: wrap if you want to speed upabout halfway through
Pull at about 203°F, probe-tenderabout 2 h before serving (rest plus a 1-hour buffer)
Rest, wrapped, in a dry cooler60–180 min, up to 4 h above 140°F
Serve6:00 pm

Charcoal: about 24 lb for the cook. Feeds: about 17–26 people at 5 oz cooked each.

Nearby weights

WeightRange at 250°FPlan
10 lb7 h 30 m – 12 h 30 m10 h 30 m
14 lb10 h 30 m – 17 h 30 m14 h 40 m
Several pieces

Time follows the biggest piece. With 3 or more, we add 10% because a full smoker recovers heat more slowly.

9 h – 15 h
Plan for 12 h 35 m at 250°F · 12 lb brisket (whole packer)
Light the cooker15 h 15 m before serving
Stallstarts near 155°F
Pull atabout 203°F and probe-tender
Rest60–180 min
Cooked meat you get5.5 – 8.3 lb

How we calculate

  1. Time range = weight × hours per pound from the sources below (ribs, chicken, tri-tip and belly are timed per piece).
  2. The plan sits 60% of the way from the short end to the long end. Finishing early is easy to fix with a longer rest; finishing late is not.
  3. Several pieces: time follows the biggest one, plus 10% when the smoker holds 3 or more.
  4. Wrapping: where a source gives wrapped times we use them; otherwise we take about 10% off for butcher paper and 20% for foil (our estimate).
  5. Light the smoker at: plan + rest + a 1-hour buffer + 45 minutes to light and settle it. Cooked yield is from the USDA Food Buying Guide.
  6. Spare ribs: our source gives one 5–6 hour estimate for pork ribs; we use it at both 225 and 250°F.

Sources disagree by an hour or more on big cuts; that spread is why we show a range. Always finish by internal temperature. Data as of Oct 2026. Full list of sources: How we calculate.

Related

Brisket smoke timesAll weights Smoke time calculatorAny cut Day plannerFull timeline with sides

FAQ

How long to smoke a 12 lb brisket?

A 12 lb brisket takes 9 h to 15 h at 250°F. Plan for 12 h 35 m; to serve at 6 pm, light the smoker by 2:45 am.

How long to smoke a 12 lb brisket at 225?

15 h to 21 h, plan for 18 h 35 m.

How long to smoke a 12 lb brisket at 275?

7 h 10 m to 12 h, plan for 10 h 05 m.

How many people does a 12 lb brisket feed?

About 17–26 people at 5 oz of cooked meat each; it yields 5.5–8.3 lb.