The water bottle equivalence is complementary data provided to help you communicate the scientific score of our water scarcity indicator. It translates a complex, abstract metric (measured in m3 water eq.) into a familiar unit for clearer communication.
It’s about impact, not just volume
First, it’s important to understand that our water scarcity indicator measures environmental stress, not just the simple volume of water used. The impact of consuming one cubic meter of water is far greater in a water-stressed region than in a water-abundant one.
This is why the indicator is measured in “cubic meters of water equivalent” (m3 water eq.)—a unit of impact—rather than just cubic meters (m3), which is a unit of volume.
How we calculate the equivalence
Our method for determining this data point is a straightforward, three-step process based on global averages.
- Establish a baseline: First, we calculated the average global water scarcity impact of producing and consuming one standard 1.5-liter bottle of water. This calculation is performed using the internationally recognized AWARE methodology, which is the standard for water scarcity impact assessment.
- Define the unit Impact: This analysis shows that a single 1.5-liter bottle has an average global impact of 0.0644 m3 water eq. This value serves as our consistent unit of comparison.
- Calculate the equivalence: We take your product’s total water scarcity score (in m3 water eq.) and divide it by the impact of one bottle (0.0644) to determine the equivalent number of bottles.
An example
If a t-shirt has a total water scarcity score of 1 m3 water eq.:
- The calculation is:
1 / 0.0644 = 15.528
This means the environmental stress on water resources from that t-shirt is equivalent to the stress caused by producing and consuming 15.5 bottles of water on a global average. This translation makes it easier to understand and communicate your product’s true water footprint.