Thanks to the magic of scheduling tools like Buffer and HootSuite, you don’t need to be chained to a desk at all hours to keep your social media feed humming, but you still need to optimize your posts by timing them to reach the largest possible audience. It wouldn’t really be true to say that we’re all glued to screens, scanning social media feeds 24/7. Rather, people tend to be active on social networks at given times. Knowing when and how frequently to populate your social media feed can help you fire off posts, tweets and status updates like precision-guided munitions.

To compile our quick cheat sheet of optimal posting times, frequencies and image sizes, we’ve leaned on the research of companies like Sprout Social (which makes social media software tools) and the aforementioned Buffer (which makes a social media scheduler).

It’s important to note that these are broad-brush guidelines distilled from the experience of millions of users. One of the best guides to your social media activity are your own analytics. Making a close study of when your fans and followers are active and when they’re engaged with your social media content is the best way to refine these generalities into your own specific best practices. And remember: Social media is a fickle beast. The algorithms that govern engagement and the visibility of your content can (and do) change frequently; what works today may not indefinitely. But who doesn’t like being kept on their toes?

*All measurements are in pixels.

Related: Instagram Tips To Grow Your Following and Your Brand 

An Easy Guide to Image Sizes for Social Media