How Long to Cook a 20 lb Turkey
4¼–4½ hours
unstuffed at 325°F · 4¼ to 4¾ hours stuffed
Done at 165°F in the thigh
USDA's chart row for 18 to 20 lb turkeys, roasted thawed at 325°F. Start checking the temperature at the low end of the range.
20 lb sits where two USDA rows meet. The next row up (20 to 24 lb) is 4½ to 5 hours unstuffed, so a bird a little over 20 lb may need longer.
Source: USDA FSIS: Let's Talk Turkey — roasting. Checked Oct 13, 2026.
Plan your turkey day
Planned on the long end of USDA's range so dinner isn't late. The thermometer, not the clock, says when it's done.
Thawing a 20 lb turkey
Worked out from CDC's rates: about 24 hours per 4 to 5 lb in the refrigerator, about 30 minutes per lb in cold water.
Cooking it from frozen
USDA says a frozen turkey takes at least 50 percent longer than a thawed one. For a 20 lb bird that is at least about 6½ to 6¾ hours unstuffed. Remove the giblet packages during cooking, once they come loose.
When it's done
- Check the thickest part of the inner thigh. CDC also suggests the innermost wing and the thickest part of the breast, avoiding bone.
- Every spot must read 165°F. If the turkey is stuffed, the center of the stuffing must reach 165°F too.
- Let the turkey stand 20 minutes before carving.
Sources: USDA FSIS: Let's Talk Turkey — roasting; CDC: Holiday turkey food safety. Checked Oct 13, 2026.