I’m going to go out on a limb and make a bold assumption: If you’re an event professional, when you chose your career you probably weren’t looking to do a lot of math.
Neither was I. However, there’s one math equation that has become pivotal to what I do: calculating the waste diversion rate of events.
The waste diversion rate is simply the percentage of waste that you divert away from landfills or incinerators. This number is necessary for determining whether an event achieved “zero waste” status. Zero waste events must have a waste diversion rate of 90% or more.
The waste diversion rate is also an important number to use to track your event’s sustainability improvement over time.
I’m going to walk you through how to calculate the waste diversion for your own events. I promise it’s not as intimidating as it sounds!
Step 1
The first step is to add up the total weight of each category of waste generated by the event. Waste includes any materials you or your suppliers don’t plan to reuse. There are four main categories of waste: recycling, compost, donations, and trash.
As example, let’s say we just completed an event that had 100 lbs. of recycling, 100 lbs. of compost, 100 lbs. of donations, and 25 lbs. of trash.
Step 2
After adding up the total weight for each category, add all of the categories together to determine the total amount of waste generated by the event.
In our example event, the total amount of waste generated is 325 lbs.
Step 3
Next, add together just the first three categories (recycling, compost, and donations). This number is the total amount of waste diverted.
For our example, the total amount of waste diverted is 300 lbs.
Step 4
Now that we have the relevant totals, we just need to turn them into a percentage. Divide the amount of waste diverted by the total amount of waste, then multiply by 100 to get the percentage.
The final equation in our example is (300 รท 325) x 100, which equals a final waste diversion rate of 92.3%!
Here’s a handy graphic to use as a cheat sheet:
You can even set this calculation up in an Excel spreadsheet with formulas to easily use for every event.
Nothing shows your clients you’re serious about sustainability more than keeping official measurements of your results. By calculating an event’s waste diversion rate, you’ll not only be able to track your improvement over time, but also offer tangible results to your clients for them to learn from and share.
Get started measuring your events’ sustainability. We offer complete waste measurement services to separate and weigh waste and calculate your event’s waste diversion rate.