- Take the deepest breath you can
- Inflate a balloon with a single breath (if you have already completed step 1 and haven’t got a balloon yet, release your breath, go and buy one, and repeat step 1)
- Tie it off
- Get a large, deep oven tray and put it on the floor
- Fill an empty bucket and put it in the centre of the oven tray
- Top up the bucket of water with extra water until it is full to the very top (don’t let any slosh into the oven tray)
- Gently dunk your balloon in the water. The water will start pouring out of the bucket and into the oven tray. Fully submerge the balloon (try not to slosh extra water out of the bucket when doing so)
- Take the balloon and bucket away
- Poor the water from the oven tray into a measuring jug, or
- Weigh the oven tray with the water in it, empty the oven tray and weigh it, the difference in weight is your lung capacity in litres (because 1 litre of water weighs exactly 1 kg)
How many litres of water did you collect? That is your lung capacity.
Why would you want to do this?
I don’t know.
Seems like a lot of work for just a number to brag to your friends about…