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LINER SIZING GUIDES
Fireplace Opening and Liner Size
Up to 600 sq. in. requires 9" liner
601-760 sq. in. requires 10" liner
761-942 sq. in. requires 11" liner
943-1,140 sq. in. requires 12" liner
1,141-1,356 sq. in. requires 14" liner
1,356-1,846 sq. in. requires 16" liner
The standard 10-1 ratio has been used in the chart above. To be safe, we recommend a 10-1 ratio for chimneys less than or equal to 25 feet in height and a 12-1 ratio for chimneys greater than 25 feet in height.


Rectangle Sizing Chart

Figure the opening for the fireplace

Rectangle

Area = length x width ÷ 12

Square

Area = length x width

Triangle

Area = (length x width) x 1/2

Original Liner Diameter
  6 7 8 9 10 11 12 13 14 16 18
4.5 6.0 8.0 10.0 11.5 13.5 15.0 17.0 19.0      
5.0 5.5 7.5 9.5 11.0 13.0 14.5 16.5 18.5 20.0 23.5  
5.5   7.0 9.0 10.5 12.5 14.0 16.0 18.0 19.5 23.0  
6.0   6.5 8.5 10.0 12.0 13.5 15.5 17.5 19.0 22.5  
6.5     8.0 9.5 11.5 13.0 15.0 17.0 18.5 22.0  
7.0     7.5 9.0 11.0 12.5 14.5 16.5 18.5 21.5  
7.5       8.5 10.5 12.0 14.0 16.0 17.5 21.0  
8.0       8.0 10.0 11.5 13.5 15.5 17.0 20.5 24.0
8.5    9.511.013.015.016.520.023.5
9.0    9.010.512.514.516.019.523.0
9.5     10.012.014.015.519.022.5
10.0     10.011.513.515.018.522.0
10.5      11.013.014.518.021.5
11.0       12.513.517.521.0
11.5       12.013.017.020.5
12.0        12.516.520.0
12.5         16.019.5
13.0         15.519.0
13.5         14.518.5
14.0          18.0
14.5          17.5
15.0          17.0
15.0          16.5
15.0          16.0



Circular Sizing Chart

Calculate the area needed for fireplace liners of circular shapes:

Circle

Area = π r2
Circumference = π d
π = 3.14
r = radius (half of diameter)
r2 = radius squared
d = diameter

Oval

Area = Rectangle+Circle
Divide the shape into a rectangle and two half circles
(1/2 circle on each end of the rectangle)
Figure the area for the rectangle
Then figure the area for the circle
Add the two areas together to get the approximate area

  4" 5" 6" 7" 8" 9" 10" 11"
12"
in²=113.14		    
17.3"
79
16.75"
86
16"
93
15.5"
99
14.25"
102
13.5"
106
11"
in²=94.99		  
16.1"
65
15.5"
72
15"
78
14.1"
73
13.5"
87
12.6"
92
 
10"
in²=78.50
16"
50
15"
57
14"
63
13.25"
68
12"
72
11.3"
76
   
9"
in²=63.58
13.1"
43
12.5"
50
12"
53
11.1"
56
10.4"
61
     
8"
in²=50.25
11.6"
36
11"
42
10.3"
45
9.5"
48
       
7"
in²=38.46
10"
36
9.2"
42
8.3"
45
         
6"
in²=28.26
8.1"
24
7.4"
25