The short answer
Use a hard cooler with 2 in. or more of foam and a lid that closes snugly but is never airtight, sized so your load fills it. Shipping? Use a molded foam cooler inside a cardboard box.
Pick your cooler by how long it has to stay cold
Time is the first filter. The longer the trip, the thicker the walls you need.
| How long | Use this cooler | Why |
|---|---|---|
| Same day | Any hard-sided cooler | Over a few hours, walls barely matter. Keep it in the shade. |
| 1 to 2 days | Thick-walled or roto-molded cooler | 2 in. of foam and a tight lid slow the loss overnight. |
| Up to 72 hours | Pre-molded foam cooler, 3.6 to 75 qt | Molded foam inside an FAA-compliant box. Built to ship. |
| Up to 7 days | Shipping & bulk cooler, 155 to 1375 qt | Thicker walls for freight, pallets and pharma. |
What makes a cooler good for dry ice
- Thick walls. 2 in. or more of dense foam. Thin walls lose the ice in hours.
- A lid that vents. Snug is good, airtight is dangerous: the CO2 gas has to escape.
- The right size. Fill it. Every empty inch is warm air your dry ice has to cool.
- A hard shell. Soft-sided coolers work for a few hours, not for a trip.
- A cardboard barrier. Extreme cold can make some plastic liners brittle. Keep a sheet between the ice and the liner.
Cooler types compared
| Type | Typical hold | Best for | Watch out for |
|---|---|---|---|
| Roto-molded | 2 to 5 days | Camping, hunting, events, a backup freezer | The gasket seals tight. Open the drain plug or leave a latch loose. |
| Foam cooler in a box | Up to 5 to 7 days | Shipping food, pharma and samples | Tape the outer box, never the foam lid. |
| Standard hard-shell | About 1 day | Day trips and local runs | Thin walls. Cheap plastic can crack in the cold. |
| Soft-sided | A few hours | Short errands only | Too little insulation to hold dry ice overnight. |
How much dry ice to put in your cooler
Estimates from our dry ice calculator for keeping food frozen at 75 °F, rounded to the nearest 5 lbs:
| Cooler size | 1 day | 2 days | 3 days |
|---|---|---|---|
| 30 qt | 20 lbs | 25 lbs | 30 lbs |
| 55 qt | 40 lbs | 50 lbs | 60 lbs |
| 75 qt | 55 lbs | 65 lbs | 80 lbs |
- Only need it chilled, not frozen? Plan on about 40% less.
- Hot day or a hot truck? At 95 °F, add about 10%.
- Other sizes or trip lengths? Run the calculator with your own numbers.
Make your dry ice last longer
- Pre-chill the cooler for a few hours with regular ice, then empty it.
- Put dry ice on top. Cold CO2 sinks and chills everything below it.
- Wrap it in newspaper or a towel to slow it down.
- Fill empty space with crumpled paper or towels.
- Open it as little as you can, and keep it out of the sun.
- Add a reflective mylar liner for extra hours on long trips.
Step by step, with a diagram: how to pack a cooler with dry ice.
Safety: three rules
- Never seal it airtight. Trapped gas builds pressure and can burst the container.
- Gloves or tongs, always. At −109 °F, dry ice burns skin in seconds.
- Keep the air moving. CO2 collects in closed cars and small rooms. Crack a window when you drive.
Shipping with dry ice: the basics
- Label the box "Dry Ice" or "Carbon Dioxide, Solid", UN 1845, with the net weight of dry ice in kg.
- Let it vent. Tape the outer box, never the foam lid, so the gas can get out.
- Check your carrier first. FedEx, UPS and USPS each set their own dry ice rules and limits.
More detail in our guides to shipping with gel packs and dry ice and frozen food shipping.
Quick answers
How long does dry ice last in a cooler?
A full, well-packed hard cooler usually holds 1 to 3 days. A molded shipping cooler holds up to 5 to 7 days. Heat, empty space and opening the lid all shorten it.
How long will 10 lbs of dry ice last?
About 24 hours in a well-insulated, well-filled cooler. Less on a hot day or in a half-empty cooler.
Can I use dry ice in a YETI or other roto-molded cooler?
Yes. Because the gasket seals tight, open the drain plug or leave a latch loose so the gas can escape, and keep cardboard between the ice and the liner.
Is a foam cooler good for dry ice?
Yes, if the walls are thick. Molded foam coolers are what shippers use: ours hold up to 72 hours. Thin, cheap foam coolers lose the ice fast.
