It's an age-old question: What size TV do I need?
As 65-inch 4K TVs become the norm and 70 to 80-inch models come in at more affordable prices, figuring out where to put your new TV becomes a challenge. In truth, most people purchase a new TV without even considering the room in which they will view the set, which can lead to a less-than ideal experience when working your way through the best shows on Netflix.
Illustration: Tom’s Guide
So, before you buy your next TV, here's how to determine the best size for your needs. This guide is intended to help you with your primary, family room television, but the same principles will work for your bedroom, den and office.
Screen size and resolution
First, remember, TVs are measured diagonally. So a 42-inch screen measures 42 inches from one corner to the opposite corner.
Next, you have to consider the resolution of the TV. That's because the higher the resolution, the closer you can sit before you'll notice pixelation in an image. That means you can sit closer to a 4K TV (3840 x 2160) than you could a 1080p TV. This is an important factor to consider when thinking about screen size; because you can sit closer to a 4K set, you don't need to get as large a TV to fill your field of view as you would with a 1080p TV.
Room size and TV position
Consider the room in which the TV will sit. As long as the furniture in that room is not permanently attached to the floor — and you're willing to move it — then you have some flexibility in the size of the TV you can get.
There’s also the question of whether you plan to set up the TV using the included stand or use a wall-mount to hang it. Using the included stand to set the TV on a table or entertainment unit will place the set closer to the viewer, shortening the viewing distance. Be sure to account for both the depth of the TV stand and whatever furniture you plan to set it on. Some sets have relatively narrow stands, but others, like the Sony Master Series A9F OLED TV extend a foot or more behind the display. By contrast, the stand that comes with the Vizio SmartCast E-Series E65-F1 adds only 6 inches of total depth.
Hanging the TV on the wall, on the other hand, can add a foot or more to the viewable distance, which can be the difference between a 60-inch TV and a 72-inch model. Depending on what sort of mount you use and the thickness of the TV, your screen will still sit a few inches from the wall, but the specifics will vary from one model to the next.
How to calculate the best size TV for your room
Measure the distance (in inches) between where you plan to mount the TV and where you plan to sit. For a 1080p TV, many industry experts such as Amazon and Crutchfield give a range of 1.5-2.5 times your screen size, though there are almost as many formulas as there are experts.
Credit: ShutterstockFor example, Amazon recommends first taking your viewing distance (in feet) and multiplying that by 7.7. So, if you have a 42-inch TV, you can sit 84 inches (7 feet) away for a comfortable and immersive experience. If you want to be safe and split the difference, you end up with a factor of 2:1, which is easy to remember. Just double the screen size for a comfortable viewing distance range.
Let's say you have a big room, a big couch, and a big coffee table between you and the television, resulting in a comfortable viewing distance of 10 feet (120 inches). You then would take 120 and divide by two, to get 60 inches.
If you're looking at a 4K ultra-high-definition television, the formula changes a bit. Because of the increased resolution, the recommended ideal viewing distance is between one and 1.5 times the screen size. So, if you bought a 50-inch TV, it should be placed between 50 to 75 inches away.
And as larger screen sizes become more affordable, with 70 to 80-inch models available for under $3,000, you'll want to take these guidelines to heart. Remember that the goal is to see the picture, not the pixels.
Recommended distance for 4K TV
Recommended distance for 1080p TV
40 inches (3.3 feet)
80 inches (6.7 feet)
42 inches (3.5 feet)
84 inches (7 feet)
48 inches (4 feet)
96 inches (8 feet)
50 inches (4.2 feet)
100 inches (8.3 feet)
54 inches (4.5 feet)
108 inches (9 feet)
60 inches (5 feet)
120 inches (10 feet)
65 inches (5.4 feet)
130 inches (10.8 feet)
72 inches (6 feet)
144 inches (12 feet)
What's comfortable for you?
The typical TV-watcher sits 9 feet from the tube, which brings us to the comfort factor: Most people like to sit far enough away from a TV that the pixels almost don't factor into the equation. So, feel free to experiment with the placement of your new TV, and it never hurts to go a little bigger than what you think you'll need.
Whether you're shopping for a TV for your home or a home for your TV, you can now figure out the perfect viewing distance with just a couple of quick calculations.