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CFM to Round Duct
Round Duct to CFM
Duct Capacity & Round to Square
CFM
Dia (in)
4
6
8
10
12
50 5 4x6 75 6 4x6 100 6 4x8 6x6 125 7 4x10 6x6 150 7 4x10 6x8 175 8 4x12 6x8 200 8 4x14 6x8 225 8 4x16 6x10 250 9 4x16 6x10 275 9 6x12 8x8 300 9 6x12 8x8 400 10 6x14 8x10 500 11 6x18 8x12 10x10 600 12 6x20 8x14 10x12 700 12 6x24 8x16 10x12 800 13 6x26 8x18 10x14 12x12 900 14 6x30 8x20 10x16 12x12 1000 14 8x22 10x16 12x14 1100 15 8x24 10x18 12x16 1200 15 8x26 10x20 12x16 1300 16 8x28 10x20 12x18 1400 16 8x30 10x22 12x18 1500 16 10x24 12x20 1600 17 10x24 12x20 1700 17 10x26 12x22 1800 18 10x28 12x22 1900 18 10x30 12x22 2000 18 12x24