How Much Air Does Your Lungs Hold?

As a science experiment, Ms Stapleton’s 3rd Class investigated how much air our lungs can hold. We have been learning about the Respiratory System, which includes the lungs and how we breathe, so this was a great experiment for us to do.


The equipment we used for our investigation included:

  • A large basin of water
  • A large plastic bottle (4 to 5 litre) with a cap
  • Plastic tubing
  • Old towels for mopping up
  • A jug
  • A marker


Before we started the investigation we marked out volume levels on the plastic bottle e.g. the 1 litre mark, 2 litre, 3 litre, 3.5 litre etc by pouring in a known volume of water. We needed a measuring jug and a ruler for this.


The scientific skills we needed for this investigating were:

  • Investigating
  • Estimating
  • Measuring


To complete the investigating we carried out the following steps:

  1. Fill the plastic bottle to the top and put on the lid.
  2. Turn it upside down in the basin of water and remove the lid.
  3. Put one end of the tube into the bottle (be careful now to let any air in).
  4. Take a big breath and then blow into the tube until you cannot breathe out any more.
  5. Observe what happens.
  6. Measure the capacity of your lungs by looking to see how much air has replaced the water in the bottle using the markings on the side of the bottle that you marked in the preparation stage.


To make sure everyone stayed healthy during our investigation we made sure we cleaned the end of the plastic tube after each child used it.

Fair Test

To make sure our investigation was a fair test we:

  • Made sure there was no air in the bottle before each person began to test.
  • Ensured each person only took one breath.
  • Ensured that each person covered the top of the tube with their finger once they had finished breathing. This was to make sure no air from the room entered the tube.


Everyone in our class measured their lung capacity by carrying out the experiment. We discovered that the best way to present our results was using a graph which we have learned to do in Maths lessons. We were very clever using Maths and Science together.

Below is a copy of our results. One child in our class had a lung capacity of 4 litres. As you can see from the graph most children had a lung capacity of 2 litres.

A New Investigation ???????

We now have a new question and maybe a new investigation. Are children with a greater lung capacity fitter than those with a lower lung capacity? What do you think?

Post Author: Sarah Stapleton