Lab Notes: The Treaty of the Metre: how the metre came to be

The next time you pick up a bag of spuds from the supermarket or fill up the car with petrol, you can thank the Treaty of the Metre for the metric system that underpins daily life.

The treaty was signed exactly 150 years ago, when delegates from 17 countries gathered in Paris to establish a new and standardised way of measuring the world around us.

But the metre's inception predates the treaty that bears its name by nearly 100 years. So how did it come about, and how has its definition changed over the centuries?

This episode was first broadcast in May 2025.

You can binge more episodes of the Lab Notes podcast with science journalist and presenter Belinda Smith on the ABC Listen app (Australia). You'll find episodes on animal behaviour, human health, space exploration and so much more. Get in touch with us: labnotes@abc.net.au

Featuring:

Bruce Warrington, CEO and chief metrologist of the National Measurement Institute

More information:

The metre originated in the French Revolution, but its definition has changed many times since

This episode of Lab Notes was produced on the lands of the Wurundjeri and Menang Noongar people.