Dry Ice Sublimation Calculator
Estimate how long your dry ice will last based on weight and storage conditions.
Pounds (lbs)
Kilograms (kg)
Open Air (Fast Sublimation)
Paper Bag / Cardboard Box
Standard Styrofoam Cooler
High-Quality Cooler (e.g., Yeti/Rtic)
Laboratory Dewar (Vacuum Insulated)
Hours
Days
Starting Weight:
0 lbs
Estimated Loss:
0 lbs
Remaining Weight:
0 lbs
Percentage Lost:
0%
Estimated Total Lifespan:
0 Hours
Understanding Dry Ice Sublimation
Dry ice is the solid form of carbon dioxide (CO2). Unlike water ice, which melts into a liquid, dry ice sublimates. This means it transforms directly from a solid state into a gas. This unique property makes it incredibly useful for shipping frozen goods, creating fog effects, and industrial cleaning, but it also means the ice disappears completely over time without leaving a puddle.
Because sublimation occurs constantly at temperatures above -109.3°F (-78.5°C), knowing the rate of loss is critical for planning shipments or events. The Dry Ice Sublimation Rate Calculator above helps you estimate how much product you will have left after a specific duration.
Rule of Thumb: In a standard Styrofoam shipping cooler, you can expect to lose approximately 5 to 10 pounds (2.3 to 4.5 kg) of dry ice every 24 hours.
Factors Affecting Sublimation Rate
The rate at which dry ice turns to gas depends on several physical factors. The calculator uses average decay rates, but your actual results may vary based on:
- Insulation Quality (R-Value): This is the most critical factor. A thick Styrofoam cooler slows sublimation significantly better than a cardboard box. High-end rotomolded coolers (like Yeti or Rtic) or vacuum-insulated Dewars offer the best retention.
- Surface Area: Dry ice typically comes in blocks, slices, or pellets. Pellets have a much higher total surface area compared to a solid block of the same weight, causing pellets to sublimate significantly faster.
- Empty Space (Dead Air): Air inside the cooler speeds up sublimation. If you have empty space in your cooler, fill it with wadded newspaper or packing peanuts to minimize air volume.
- Ambient Temperature: Dry ice stored in a hot car trunk will disappear much faster than dry ice kept in a cool, air-conditioned room.
Typical Sublimation Rates by Storage Type
To help you estimate manually, here are the typical loss rates used in industry standards:
- Open Air: Extremely fast loss. A block can disappear completely in a few hours.
- Paper Bag / Thin Cardboard: Poor insulation. Expect 10-15% loss per hour.
- Standard Styrofoam Cooler: The industry standard for shipping. Expect 15-20% loss per 24 hours (or roughly 5-10 lbs/day).
- High-Performance Cooler: excellent retention. Expect roughly 5-10% loss per 24 hours.
Safety Precautions
When handling dry ice and calculating your needs, always prioritize safety:
- Ventilation is Key: As dry ice sublimates, it releases CO2 gas. If stored in a small, unventilated area (like a closed car or small room), it can displace oxygen and cause asphyxiation. Always leave a window cracked.
- Do Not Use Airtight Containers: The expansion ratio of solid CO2 to gas is roughly 1:800. If you seal dry ice in an airtight container (like a plastic bottle or screw-top jar), the pressure will build up until the container explodes.
- Skin Protection: Dry ice is -109.3°F. Direct contact with skin can cause severe frostbite instantly. Always use leather gloves or tongs.
How to Maximize Dry Ice Life
If the calculator shows you won't have enough ice for your duration, try these tips to extend its life:
- Buy Blocks, Not Pellets: Blocks have less surface area and last longer.
- Wrap It: Wrapping the dry ice block in several layers of newspaper acts as additional insulation.
- Minimize Opening: Every time you open the cooler, warm air rushes in and speeds up sublimation.
- Fill the Gaps: Reduce dead air space by filling voids with towels or packing paper.