Dry ice usually lasts anywhere from a few hours to a few days, depending mainly on how much you have and how well it’s insulated.

Quick Scoop: How long does dry ice last?

  • Left out at room temperature or outdoors, dry ice typically lasts about 3–5 hours before it’s gone.
  • A 5 lb block in a typical cooler generally lasts around 18–24 hours if you’re not opening it constantly.
  • In a basic Styrofoam or similar insulated box, dry ice can last roughly 24–48 hours, sometimes longer with thicker walls and a cool environment.
  • High‑quality, very well‑insulated containers can stretch dry ice life to several days (2–4 days or more, depending on amount and insulation).
  • On a per‑pound basis, you can expect roughly 2–4 hours of life, with 5–10 lb typically sublimating over about 24 hours in normal conditions.

What affects how long dry ice lasts?

  • Amount of dry ice: Larger blocks and more total weight last longer than small chunks.
  • Insulation: Better coolers and thick Styrofoam/EPP boxes slow sublimation and extend life.
  • Temperature and airflow: Heat and moving air make dry ice disappear faster; shade, cool rooms, and closed lids help it last.
  • How often you open the container: Every time you open the cooler, warm air rushes in and speeds up sublimation.

Simple rule of thumb

If you’re planning for an event or trip, think in terms of about 5–10 lb of dry ice per day in a decent cooler, adjusting upward if it’s hot or you’ll be opening the lid a lot.

Information gathered from public forums or data available on the internet and portrayed here.