Paintball CO2 Shots Calculator
Estimate how many paintball shots you get from a CO2 tank of a given size, plus refills for a full day of play.
How it works
Shots per fill = tank size (oz) × shots per ounce · Games per fill = shots ÷ paint per game
CO2 propels the ball by boiling from liquid to gas, and each ounce releases enough gas for roughly 30–50 shots on a typical marker. Colder air lowers the vapour pressure, so cold-weather play cuts the shots per ounce noticeably — which is why HPA (compressed air) is preferred for consistency. Multiply your tank's ounce capacity by a realistic shots-per-ounce figure to plan how many refills a day of play will need.
Worked example
A 20 oz CO2 tank at 40 shots per ounce yields about 800 shots. At 200 balls per game that covers roughly 4 games, and you would need about 1.25 fills to reach 1,000 shots.
Frequently asked questions
How many shots does a 20 oz CO2 tank give?
Around 800 shots at a typical 40 shots per ounce, but it ranges from roughly 600 in cold weather to 1,000+ in warm conditions with an efficient marker. CO2 output drops sharply as temperature falls.
Why does cold weather reduce my shot count?
CO2 works by evaporating from liquid, and its vapour pressure falls as temperature drops. In the cold the tank cannot gasify quickly enough, causing velocity drop-off and fewer usable shots per ounce.
Is CO2 or HPA better?
HPA (high-pressure air) delivers far more consistent velocity across temperatures and is gentler on markers, which is why it dominates tournament play. CO2 is cheaper to fill and fine for casual, warm-weather recreational use.
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This calculator is for educational purposes. Double-check important results before acting on them.