How We Calculate Dry Ice
There isn't one fixed amount of dry ice that works for every meat shipment. Our calculator estimates how much you need based on the size of your cooler, the thickness of its insulation, the weight of the frozen meat, and how long the package needs to stay frozen.
The basic calculation follows the standard heat-transfer method described by ASHRAE for insulated shipping containers: larger boxes have more surface area for heat to enter through, while thicker insulation slows that heat down. We then convert that expected heat gain into dry-ice usage using the heat absorbed when dry ice turns directly from a solid into carbon dioxide gas—about 245 BTU per pound, based on National Bureau of Standards/NIST data.
The calculator assumes your meat is already frozen solid before packing. Dry ice is much better used to keep frozen meat frozen than to cool warm or partially frozen meat. Meat weight still matters because frozen meat itself provides thermal mass: a tightly packed 40-pound box of frozen meat generally does not need eight times as much dry ice as a similar box containing 5 pounds.
Finally, we add a safety allowance because real packages encounter air leaks, warm delivery trucks, direct sun, handling, and unexpected delays that a simple insulation calculation can't perfectly predict. As a reality check, UPS recommends approximately 5–10 pounds of dry ice per 24 hours depending on the shipment and insulation, while FedEx similarly recommends 5–10 pounds per 24 hours and enough additional dry ice for another 24 hours in case of delays.
The result is still an estimate. Actual dry-ice use can vary considerably with the cooler, packing method, outside temperature, and conditions your package encounters in transit.