August 21, 2005 / By Art Feierman

Here are your basic formulas for calculating projector screen dimensions. They are slightly rounded for your convenience.

All calculations are based on the screen area, and *do not include the borders or frame.*

These calculations are for standard 16:9 aspect ratio screens (HDTV shape), which are used by the vast majority of home theater users, as the vast marjority of home theater projectors are 16:9 native aspect ratio.

Simply put, a 16:9 projection screen is 1.78 times as wide as it is high. 16 / 9 = 1.78 (rounded)

If you know your projector screen’s diagonal size:

Projector Screen Height: To calculate the projector screen height, multiply the diagonal by approximately 0.495. (In other words the height of the screen is just a bit less than 50% of the diagonal.

Projector Screen Width: The width of the projector screen is approximately 87% of the projector screen’s diagonal, so multiply the diagonal measurement by approximately 0.87.

**Examples:Diagonal Size of a home theater projector screen: 100″**

Projector screen height: 0.495 x 100″ = 49.5 inches

Projector screen width: 0.87 x 100″ = 87 inches

**Diagonal Size of a home theater projection screen: 110″**

Projector screen height: 0.495 x 110″ = 54.5″

Projector screen width: 0.87 x 110″ = 95.7″

If you know projection screen width, and need to calculate diagonal size and height of the screen:

Projector screen diagonal: To calculate the projector screen diagonal from the known width, divide the width by 0.87

Projector screen height: To calculate the projection screen height, from the known width, multiply the width by 0.57

**Width of a home theater projector screen: 100″**

Projector screen diagonal: 100″ / 0.87 = 115″

Projector screen height: 100″ * 0.57 = 57″

**Width of a home theater projection screen: 80″**

Projector screen diagonal: 80 ” / 0.87 = 92 ”

Projector screen height: 80 ” * 0.57 = 45.6 ”

It’s that easy.

Simply put, a 16:9 projection screen is 1.78 times as wide as it is high. 16 / 9 = 1.78 (rounded)

If you know your projector screen's diagonal size:

Projector Screen Height: To calculate the projector screen height, multiply the diagonal by approximately 0.495. (In other words the height of the screen is just a bit less than 50% of the diagonal.

Projector Screen Width: The width of the projector screen is approximately 87% of the projector screen's diagonal, so multiply the diagonal measurement by approximately 0.87.

**Examples:
Diagonal Size of a home theater projector screen: 100" **

Projector screen height: 0.495 x 100" = 49.5 inches

Projector screen width: 0.87 x 100" = 87 inches

**Diagonal Size of a home theater projection screen: 110"**

Projector screen height: 0.495 x 110" = 54.5"

Projector screen width: 0.87 x 110" = 95.7"

If you know projection screen width, and need to calculate diagonal size and height of the screen:

Projector screen diagonal: To calculate the projector screen diagonal from the known width, divide the width by 0.87

Projector screen height: To calculate the projection screen height, from the known width, multiply the width by 0.57

**Width of a home theater projector screen: 100" **

Projector screen diagonal: 100" / 0.87 = 115"

Projector screen height: 100" * 0.57 = 57"

**Width of a home theater projection screen: 80"**

Projector screen diagonal: 80 " / 0.87 = 92 "

Projector screen height: 80 " * 0.57 = 45.6 "

It's that easy.

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