Water Pipe Sizing Charts

Water Supply Fixture Units (WSFU) and Minimum Fixture Branch Pipe Sizes

Important notes: Appliances, appurtenances, and fixtures not referenced in the table below shall be permitted to be sized by reference to fixtures having a similar flow rate and frequency of use. The listed fixture unit values represent their load on the cold water building supply. The separate cold water and hot water fixture unit value for fixtures having both hot and cold water connections shall be permitted to be each taken as three-quarter of the listed total value of the fixture.

For fixtures or supply connections likely to impose continuous flow demands, determine the required flow in gallons per minute (gpm or L/s) and add it separately to the demand in gpm (L/s) for the distribution system or portions thereof.

Mimimum fixture branch pipe size refers to the size of the cold branch pipe, or both the hot and cold branch pipes. The listed minimum supply branch pipe sizes for individual fixtures are the nominal (ID) pipe size.

Appliances, Appurtenances, or Fixtures Minimum Fixture Branch Pipe Size (inches) Private Public
Bathtub or Combination Bath/Shower 1/2 4.0 4.0
3/4" Bathtub Fill Valve 3/4 10.0 10.0
Bidet 1/2 1.0 --
Clothes Washer 1/2 4.0 4.0
Dental Unit, Cuspidor 1/2 -- 1.0
Dishwasher, Domestic 1/2 1.5 1.5
Drinking Fountain or Water Cooler 1/2 0.5 0.5
Hose Bibb 1/2 2.5 2.5
Hose Bibb, Each Additional 1/2 1.0 1.0
Lavatory 1/2 1.0 1.0
Lawn Sprinkler, Each Head -- 1.0 1.0
Mobile Home, Each (minimum) -- 12.0 --
Bar Sink 1/2 1.0 2.0
Clinic Faucet SInk 1/2 -- 3.0
Clinic Flushometer Valve Sink (with or without faucet) 1 -- 8.0
Kitchen Sink, Domestic (with or without dishwasher) 1/2 1.5 1.5
Laundry Sink 1/2 1.5 1.5
Service Sink or Mop Basin 1/2 1.5 1.5
Washup Sink (each set of faucets) 1/2 -- 2.0
Shower, Per Head 1/2 2.0 2.0
Urinal, Flush Tank 1/2 2.0 2.0
Wash Fountain (circular spray) 3/4 -- 4.0
Water Closet, 1.6 GPF Gravity Tank 1/2 2.5 2.5
Water Closet, 1.6 GPF Flushometer Tank 1/2 2.5 2.5
Water Closet, Greater Than 1.6 GPF Gravity Tank 1/2 3.0 5.5

Reduced fixture unit loading for additional hosebibbs is to be used where sizing total building demand and for pipe sizing where more than one hose bibb is supplied by a segment of water distribution pipe. The fixture branch to each hose bibb shall be sized on the basis of 2.5 fixture units.

Fixture Unit Table for Determining Water Pipe & Meter Sizes

Meter & Street Service (inches) Building Supply & Branches (inches) Maximum Allowable Length (feet)
40 60 80 100 150 200 250 300 400 500 600 700 800 900 1000
Pressure Range - 30 to 45 psi (available static pressure after head loss)
3/4 1/2 6 5 4 3 2 1 1 1 0 0 0 0 0 0 0
3/4 3/4 16 16 14 12 9 6 5 5 4 4 3 2 2 2 1
3/4 1 29 25 23 21 17 15 13 12 10 8 6 6 6 6 6
1 1 36 31 27 25 20 17 15 13 12 10 8 6 6 6 6
3/4 1-1/4 36 33 31 28 24 23 21 19 17 16 13 12 12 11 11
1 1-1/4 54 47 42 38 32 28 25 23 19 17 14 12 12 11 11
1-1/2 1-1/4 78 68 57 48 38 32 28 25 21 18 15 12 12 11 11
1 1-1/2 85 84 79 65 56 48 43 38 32 28 26 22 21 20 20
1-1/2 1-1/2 150 124 105 91 70 57 49 45 36 31 26 23 21 20 20
2 1-1/2 151 129 129 110 80 64 53 46 38 32 27 23 21 20 20
1 2 85 85 85 85 85 85 82 80 66 61 57 52 49 46 43
1-1/2 2 220 205 190 176 155 138 127 120 104 85 70 61 57 54 51
2 2 370 327 292 265 217 185 164 147 124 96 70 61 57 54 51
2 2-1/2 445 418 390 370 330 300 280 265 240 220 198 175 158 143 133
Pressure Range - 46 to 60 psi (available static pressure after head loss)
3/4 1/2 7 7 6 5 4 3 2 2 1 1 1 0 0 0 0
3/4 3/4 20 20 19 17 14 11 9 8 6 5 4 4 3 3 3
3/4 1 39 39 36 33 28 23 21 19 17 14 12 10 9 8 8
1 1 39 39 39 36 30 25 23 20 18 15 12 10 9 8 8
3/4 1-1/4 39 39 39 39 39 39 34 32 27 25 22 19 19 17 16
1 1-1/4 78 78 76 67 52 44 39 36 30 27 24 20 19 17 16
1-1/2 1-1/4 78 78 78 78 66 52 44 39 33 29 24 20 19 17 16
1 1-1/2 85 85 85 85 85 85 80 67 55 49 41 37 34 32 30
1-1/2 1-1/2 151 151 151 151 128 105 90 78 62 52 42 38 35 32 30
2 1-1/2 151 151 151 151 150 117 98 84 67 55 42 38 35 32 30
1 2 85 85 85 85 85 85 85 85 85 85 85 85 85 83 80
1-1/2 2 370 370 340 318 272 240 220 198 170 150 135 123 110 102 94
2 2 370 370 370 370 368 318 280 250 205 165 142 123 110 102 94
2 2-1/2 654 640 610 580 535 500 470 440 400 365 335 315 285 267 250
Pressure Range - over 60 psi (available static pressure after head loss)
3/4 1/2 7 7 7 6 5 4 3 3 2 1 1 1 1 1 0
3/4 3/4 20 20 20 20 17 13 11 10 8 7 6 6 5 4 4
3/4 1 39 39 39 39 35 30 27 24 21 17 14 13 12 12 11
1 1 39 39 39 39 38 32 29 26 22 18 14 13 12 12 11
3/4 1-1/4 39 39 39 39 39 39 39 39 34 28 26 25 23 22 21
1 1-1/4 78 78 78 78 74 62 53 47 39 31 26 25 23 22 21
1-1/2 1-1/4 78 78 78 78 78 74 65 54 43 34 26 25 23 22 21
1 1-1/2 85 85 85 85 85 85 85 85 81 64 51 48 46 43 40
1-1/2 1-1/2 151 151 151 151 151 151 130 113 88 73 51 51 46 43 40
2 1-1/2 151 151 151 151 151 151 142 122 98 82 64 51 46 43 40
1 2 85 85 85 85 85 85 85 85 85 85 85 85 85 85 85
1-1/2 2 370 370 370 370 360 335 305 282 244 212 187 172 153 141 129
2 2 370 370 370 370 370 370 370 340 288 245 204 172 153 141 129
2 2-1/2 654 654 654 654 654 650 610 570 510 460 430 404 380 356 329

Building supply, not less than 3/4 of an inch (20 mm) nominal size

The charts provided here were taken from the 2012 Uniform Plumbing Code®. Please note that neither PlumbingSupply.com® nor IAPMO assume liability of any kind resulting from your use of the information presented. We strongly recommend that you seek the assistance and/or advice of a licensed plumber for any plumbing project.

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