That's a great and practical question! There isn't a single universal timeline, like "every Tuesday," because how often you need to replace your trash bin liners depends on a few key factors. Generally, for a typical kitchen bin, you'll likely change the liner every time you take out the full bag of trash. However, the liner itself might need replacing sooner if it gets damaged.
The main factors are what you're throwing away and the liner's quality. Wet waste, like food scraps or used coffee grounds, can degrade a bag quickly and lead to leaks and smells. In this case, you should replace the liner immediately after disposal to prevent a mess. For dry recycling or general waste, a sturdy liner can often last until the bin is full. A high-quality, thick liner resists tears and holds up longer than a flimsy one.
Look for these signs it's time for a new liner: visible tears or holes, lingering odors after the trash is gone, or moisture/seepage at the bottom of the bin. A good rule of thumb is to use a liner durable enough to last until the bin is full, but always replace it promptly if there's any risk of leaks. Investing in stronger bags and giving your empty bin a quick wipe-down when you change the liner will keep things fresh and hygienic for much longer.