The most popular balloon size for parties is the 12 inch latex balloon. The 12 inch balloon is the most popular for wedding balloons, birthday balloons, personalized balloons and custom printed balloons. The 10 inch balloon is smaller but the float time is also shorter. We recommend 10 inch balloons for parades and fairs when the float time is not critical. For wedding balloons we recommend the 12 inch balloon because the float time is about 10-12 hours and up to 24 hours under certain ideal conditions. If you need a for sure 24 hour float time, be sure to get the 14 inch.