Hello, and thank you for your comment. Each Balloon Time tank has approximately 15% more capacity than what is needed to fill the indicated number of balloons when used properly. However, other factors may alter the total amount of balloons inflated, such as using balloons other than those supplied in a kit or using larger balloons. In addition, always ensure you have a good seal between the nozzle and balloon neck so no helium escapes while inflating, and tightly close the valve when storing your tank to prevent helium leakage. We can easily be reached at: BalloonTime&#64;WorthingtonIndustries.com. if you have any additional questions. <br />Thank you.