Balloons are often part of our fondest recollections from childhood. Whether it is a balloon that you got at a birthday party and wanted to keep forever (or pop right there in the party!) or one of those mysterious balloons that escaped your clutches at an amusement park and soared skyward, where you followed it for miles until it disappeared from sight.

You have likely been to plenty of events where you could buy these types of balloons, but have you ever wondered just how strong balloons really are? More specifically, how many balloons would it take to lift you off the ground and allow you to fly?

### Lifting Force

Gas balloons work on the principle of buoyancy and are filled with helium gas. These balloons displace a certain amount of air (just like a ship does to stay above the surface of water), so as long as the combined weight of the balloon and the strings is lesser than the air it displaces, you’re in good shape. This is because the weight of helium gas is less than air, so it has no problem floating. However, this is not the only reason behind the flying ability of balloons; there are a host of other factors to consider.

The lifting force of a helium-filled balloon is 1 gram per liter. This means that if you fill a balloon with 10 liters of helium gas, it should be able to lift an object no heavier than 10 grams. This is the capacity of a helium-filled balloon when it comes to lifting weights. For the sake of simplicity in this discussion, let’s consider the weight of the strings and the balloon itself to be negligible.

### Volume of a Balloon

Although a gas-filled balloon can have many possible shapes, let’s consider one that is spherical. A typical spherical balloon at an amusement park is 30 centimeters (0.98 ft) in diameter. This is just a standard value; balloons can be much bigger, and much smaller. So, how much helium gas can this particular balloon hold? Let’s calculate the volume (or the gas-holding capacity) of the balloon.

Since the balloon is spherical in shape, we shall use the formula for calculating the volume of a sphere, which is,

where ‘r’ is the radius of the balloon (which is 30/2 = 15 centimeters, in this case).

After entering the variables, we find that the volume of our balloon is 14130 cubic centimeters, which translates to approximately 14 liters.

### Weight of a Person

Consider a man who weighs 60 kilograms (132 pounds). In grams, this amounts to 60,000 grams. Divide your weight (60,000 grams) by 14 (liters). It will come to approximately 4,286.

Note that this number of balloons can only just lift you off the ground; in order to rise in the air with any speed, it will take almost 500 more balloons. Ultimately, it takes **4,800 balloons **to get a person weighing 60 kilograms (132 pounds) off the ground.

Obviously, this number would change according to the size of the balloons and the weight of the person being lifted.

In other words, if you’re thinking of transporting yourself and your house just by using gas-filled balloons, think again. Or at least…start buying balloons in bulk, because you’ll need them!

### References

- Union University
- Hawaii Ham Radio Information
- Concordia College in Moorhead, MN
- HowStuffWorks
- ExplainThatStuff