Which TV size for which seating distance? Table and rule of thumb

"What size should it be?" is the first question in almost every consultation. The answer is not in the brochure but in the living room: it follows from the distance between sofa and wall. Anyone who measures that distance and applies one of the following formulas buys the right diagonal.

The rule of thumb by resolution

The rule: seating distance = screen diagonal × factor. The factor depends on how finely the picture is resolved, because from too close you see individual pixels, from too far you waste detail.

Since almost all sets from 43 inches upwards are 4K today, the factor of 1.2 to 1.6 is the rule we work with. Take the smaller value for film nights, the larger one if the television mostly runs in the background.

Viewing distance by TV size: the table

Calculated for 4K with a factor of 1.2 to 1.6. Width and height refer to the 16:9 picture area; with its frame, the set is one or two centimetres larger.

Seating distance and recommended diagonal at 4K

The other way round, starting from the sofa:

Measure from the picture surface to the eyes, not to the edge of the sofa.

What size TV for a 4 metre viewing distance?

At four metres, a 98 or 100 inch TV fits, and for film nights the rule of thumb would allow even more. TVs of that size are heavy, deep and take effort to mount, so from here it pays to compare them with a projector and a screen of 120 inches or more. At 3.5 metres, 85 inches is the right choice.

How far should you sit from a 55 inch TV?

For a 55 inch 4K TV, 1.7 to 2.2 metres is ideal. The picture is around 122 cm wide. If you sit three metres away, a 75 inch set is the better fit.

How far should you sit from a 65 inch TV?

For a 65 inch 4K TV, sit between 2.0 and 2.6 metres away. That is the typical distance between sofa and wall in many living rooms. The picture is around 144 cm wide.

How far should you sit from an 85 inch TV?

For an 85 inch 4K TV, sit between 2.6 and 3.5 metres away. An 85 inch set is around 188 cm wide and needs a wall at least two metres wide so it does not look cramped.

How far should you sit from a 100 inch TV?

For a 100 inch 4K TV, sit between 3.0 and 4.1 metres away. The picture is around 2.2 metres wide and 1.25 metres high, with a diagonal of 254 cm. Before buying, check whether the set fits through the stairwell and doors and whether the wall can carry the weight.

Converting inches to cm

One inch is 2.54 centimetres. The size in inches always refers to the picture diagonal, measured from the bottom left to the top right corner of the screen area. Spec sheets often also give a value in centimetres. It is usually one to two centimetres below the calculated value, because the visible screen area is slightly smaller than the size class. That is why a 50 inch TV is sometimes listed at 125 cm and sometimes at 127 cm.

How many inches is a 125 cm TV?

Around 50 inches. 125 cm divided by 2.54 gives 49.2 inches, and many manufacturers list their 50 inch models at 125 or 126 cm. The picture is around 111 cm wide, and the right viewing distance is 1.5 to 2.0 metres.

How many inches is a 165 cm TV?

Exactly 65 inches, because 165 divided by 2.54 gives 65. The picture is around 144 cm wide and 81 cm high, and 2.0 to 2.6 metres is the ideal distance. If the spec sheet says 163 or 164 cm, it is the same size class.

What TV size fits a width of 140 cm?

Divide the width in centimetres by 2.21 to get the diagonal in inches. A picture width of 140 cm comes to around 63 inches. A 65 inch TV, however, is around 145 cm wide including the frame, so it will not fit a 140 cm recess. A 55 inch set belongs there, at around 123 cm wide. A width of 95 cm takes you to 43 inches.

How many centimetres is a 77 inch TV?

The diagonal measures 196 cm. The picture is around 171 cm wide and 96 cm high, and the frame adds one to two centimetres. The right viewing distance is 2.4 to 3.1 metres.

Viewing angle per THX and SMPTE

The film industry counts not in inches but in degrees: how much of the field of view does the picture fill? SMPTE recommends at least 30 degrees of horizontal viewing angle for cinemas; THX names 36 to 40 degrees as the target for the best row. Converted to a 16:9 picture, 30 degrees means a distance of about 1.6 times the diagonal, 40 degrees around 1.2 times. That is exactly the range from the rule of thumb. So anyone wanting a "cinema feeling" with 4K material sits towards the near end of the table.

Why most people buy too small

In the shop a 75 inch set hangs next to an 85 inch one in a hall ten metres wide, at home it stands alone on a four metre wall. The scale shifts, and almost all customers we ask after installation say: "Bigger would have been fine." Two tips from practice: tape the picture area on the wall with masking tape and look at it for two days. And think in width: with its frame, a 65 inch TV is around 145 cm wide, 77 inches 171 cm, 85 inches 189 cm. If the width fits the furniture and the wall recess, the size fits.

A second reason is the price jump between two sizes. The decision "one class smaller, but the better panel" is sometimes right, if the distance really is short. At over three metres, screen area almost always wins.

When a projector makes more sense

Televisions exist today up to 98 and 100 inches, but they are heavy, deep and do not fit through every stairwell. From about 3.5 metres of seating distance and a wish for over 100 inches, a projector with a screen becomes the superior solution: 120 inches corresponds to 2.66 metres of picture width, and the picture disappears during the day when the screen is retracted. The precondition is that the room can be darkened. For living rooms flooded with light, a large television or a laser TV with a special screen remains the better choice.

Conclusion

Measure the distance, multiply by 1.2 to 1.6, choose the diagonal in that range and, if in doubt, the larger one. We measure the seating distance at your home and tape the diagonal on the wall before you commit. Anyone who brings the wall width and the distance goes home with a clear figure.

More on this: TV advice at home and TV wall mounting.