Reusable vs Disposable Bags

Many stores charge a small fee for disposable plastic bags. Investing in a durable reusable bag can eliminate those charges and reduce plastic waste. This calculator shows how many shopping trips it takes before the reusable option saves you money.

The Break-Even Formula

Assuming you use the same number of bags per trip, the equation for break-even trips is:

Here $C$ represents the cost of the reusable bag, $p$ is the per-bag fee for disposable plastic, and $b$ is how many bags you typically use per trip. The result tells you how many trips are needed to recover the reusable bag’s price.

Example Calculation

If your cloth bag costs $5 and the store charges $0.10 per plastic bag, using three bags per trip means break-even occurs after $N=\frac{5}{0.10\times 3}$, or roughly 17 trips.

Environmental Impact

Beyond the dollars, every reusable trip prevents more plastic from entering landfills and waterways. Using a sturdy bag can replace hundreds of disposables over its lifetime, helping cut down on pollution and production emissions.