Once upon a time, buying a “big screen” TV meant shelling out a small fortune to watch fuzzy video on a bulky appliance the size of a bedroom dresser. Times have certainly changed. Today, $500 will score you a 55-inch panel with pristine image quality that you can hang from the wall.

Now that “big screen” TVs have become so common as to not even warrant the name, just how big should you go with your next TV purchase? It’s a seemingly simple question that’s not always easy to answer. Thankfully, there’s a straightforward formula that can help you decide.

Finding the ideal screen size

If you’ve ever sat front row at a movie theater, you know that getting up close and personal to a large screen can be overwhelming. Sitting too close to a big screen – or too far from a small one – is no fun. That’s why the intended viewing distance for your TV is an important factor in choosing a screen size.

Several video industry groups have offered simple formulas to determine the ideal screen size for your TV needs. THX recommends multiplying the viewing distance (in inches) by 0.84 to get their ideal screen size. For example, the popular TV viewing distance of 9 feet (108 inches) would suggest a screen size of about 90 inches (0.84 x 108 = 90.72). The Society of Motion Picture and Television Engineers recommends a more modest multiplier of 0.625, which equals a 68-inch screen for the same 9-foot viewing distance (0.625 x 108 = 67.5).

These recommendations aren’t concrete rules (few people would want a 90-inch TV in their living rooms), but they should give you an idea of what size screen will offer a good viewing experience for your home setup.

Limiting factors to consider

It’s not always possible or advisable to go with a TV as big as the formulas above recommend. Before you commit to your purchase, follow these considerations:

  • Space: Measure the wall, entertainment center or other space where you plan to install your TV to ensure it can accommodate the model you choose.
  • Height: Preferences differ, but the ideal TV elevation is usually with the screen’s center at eye level, and the larger TV you choose, the higher that center will be.
  • Views: Arrange your seating area and other furniture as desired, and check to guarantee nothing will obstruct the views of your planned TV size.
  • Décor: Even with today’s stylish designs, a big black rectangle can overwhelm a room’s décor, so make sure your pick doesn’t clash with your room’s décor.
  • Budget: While TVs are cheaper than ever, the bigger you go, the more you’ll usually pay.

Final thoughts

Keep in mind that common TV screen size measurements refer to the diagonal distance across the screen. Look up the specs for a specific model to learn the exact dimensions of the entire TV.

Checking out the screen sizes of TVs in person at a department or electronics store is a good way to get a sense of their size. To help visualize a particular size TV in your home, you can cut out a large sheet of cardboard or paper and hang it where you plan to place the screen.

For TV buying guides and reviews, visit Consumer Reports, RTINGS.com or Wirecutter.