To calculate carbon footprint, first we look at each product’s ‘CO2e footprint’. The ‘e’ is for “equivalent” which incorporates all greenhouse gases including carbon dioxide and methane. It’s measured “cradle-to-gate,” which includes materials extraction and processing, manufacturing, and transportation. This data comes directly from cloud-based lifecycle inventories including ecoinvent, through a tool called the 2030 Calculator. This assessment is an estimate since we don't have perfect information for every product, but it's pretty accurate and gives you a direction on emissions tied to the creation of the product.

It’s helpful to know the carbon footprint of a product, but it only tells you so much when you’re shopping. There’s huge variability between products both across and within shopping categories; how does one compare small pans to big ones, or say a blender to a butter knife?

To make it easier for consumers to evaluate a product’s relative carbon footprint, we include an absolute CO2e footprint score. We also look at a functional score called a ‘carbon efficiency ratio,’ which is calculated as CO2e/kg. The carbon efficiency ratio is a good indicator of which products are using the most carbon efficient materials, processes and transport.

Using this method, we can also spot outliers within a shopping category that drive outsized cost to the environment for the utility that a product offers, either from an absolute or relative CO2e footprint perspective. When we find one of those products, we remove it from our highlighted products. 

To score products for durability, we assess several factors including research on generally assumed lifespan for product categories, scientific assessment of tensile and compressive strength for raw materials in each product, and a comprehensive look at how products are actually faring after purchase in the real world.

We also take into account manufacturer warranties, which generally function as a guarantee of durability. Warranties place a financial responsibility on the manufacturer to use durable materials and workmanship to extend the lifespan of a product.

Products are considered more sustainable if they use a higher percentage of recycled content, as well as readily recyclable, compostable or biodegradable materials.

In addition to evaluating the composition of products, we give higher scores to those companies that offer ‘take-back’ programs. Take-back programs allow consumers to return a product at the end of its useful life, placing responsibility on the manufacturer to dispose of the product and/or its packaging. These programs typically incentivize manufacturers to design their products to be easily disassembled and recycled or upcycled, contributing to a circular economy.

Certifications play a vital role in ensuring that manufacturers' claims are in fact true. With thousands of eco-certifications in existence, we evaluate each certification to avoid giving products credit for “greenwashing” certifications that aren’t based in science.

Evergrade gives higher scores to products that use efficient, environmentally responsible packaging materials. We look for packaging that uses recycled content, compostable materials, or at a minimum, certified sustainably-harvested virgin materials. It’s also valuable for the end consumer to be able to easily recycle or compost packaging at home. 

In addition to evaluating the packaging materials, we deduct points from companies that use inefficient shipping materials such as unnecessary double wrapping, double boxing, or materials like styrofoam, which have negative impacts to the planet.