6" Diameter Min Code Fall: 1/16" per foot (or 1/8" per foot) 0.52% Grade (1:192) IPC Table 704.1

6" Drain & Sewer Pipe Slope Calculator

Under model plumbing codes (IPC & UPC), a horizontal 6" gravity drainage pipe must be installed with a minimum fall of 1/16" per foot (or 1/8" per foot) (0.52% pitch or 1:192 slope ratio) to ensure self-scouring velocity (2.0 ft/s). Part of our master Drain Pipe Slope Calculator and Flow Rate Calculator suite.

Presets:

Slope Profile 1.67% Grade

Calculated Drain Slope

0.52% 1 : 192.0

Equivalent Fall: 0.063" per ft (0.63" per 10 ft)

Total Fall (Drop) 1.25 in

Horizontal Run 20.00 ft

Fall per Foot 0.063 in/ft

Actual Cut Length 20.00 ft

Your drain pipe drops 1.25 inches over a 20.00 ft horizontal run. This produces a 0.52% slope (1 : 192.0 ratio), dropping 0.063 inches per foot (0.63 inches per 10 feet).

Code Elevation Drop Schedule

6" Drain Pipe Fall vs. Run Length Chart

Exact elevation drop required over distance at standard 1/16" per foot (or 1/8" per foot) slope (0.52% grade).

Horizontal Run (Ft)	Required Drop (Inches)	Ft-Inches Format	Metric Fall (mm)	Code Compliance Status
5 ft	0.31 in	0' 0.3"	7.9 mm	✓ Meets IPC/UPC
10 ft	0.63 in	0' 0.6"	15.8 mm	✓ Meets IPC/UPC
15 ft	0.94 in	0' 0.9"	23.8 mm	✓ Meets IPC/UPC
20 ft	1.25 in	0' 1.3"	31.7 mm	✓ Meets IPC/UPC
30 ft	1.88 in	0' 1.9"	47.5 mm	✓ Meets IPC/UPC
40 ft	2.50 in	0' 2.5"	63.4 mm	✓ Meets IPC/UPC
50 ft	3.13 in	0' 3.1"	79.2 mm	✓ Meets IPC/UPC
75 ft	4.69 in	0' 4.7"	118.9 mm	✓ Meets IPC/UPC
100 ft	6.25 in	0' 6.3"	158.5 mm	✓ Meets IPC/UPC

Plumbing Code Compliance

IPC & UPC Code Rules for 6" Sanitary Piping

Regulatory parameters, maximum fixture unit capacities, and velocity thresholds.

Minimum Code Slope
1/16" per foot (or 1/8" per foot)
0.52% Grade (1:192)

Drop Per 10 Feet

0.625 inches

Elev. delta per 10ft stick

Drop Per 50 Feet

3.125 inches

Total fall for 50ft run

Max Drainage Fixture Units

620 DFU

At minimum allowable slope

Min Scouring Velocity

2 ft/sec

Self-cleaning threshold

Governing IPC Reference

Table 704.1

International Plumbing Code

Primary Fixtures Connected to 6" Drains:

Commercial municipal sewer mains
Industrial facility sanitary outfalls
Campus underground gravity sewer networks

Trade Installation Advisory: Large commercial buildings, hotels, apartment complexes, and hospital site utilities connecting to municipal city mains.

Pipe Diameter Navigation

Compare Slope Requirements for Other Pipe Sizes

Explore sanitary fall and grade rules across different drain diameters.

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Expert FAQ Guide

6" Drain Pipe Slope FAQs

Code questions and fall calculations for 6" sanitary drainage piping.

2 Questions Answered

Q1 What is the minimum code slope for 6" sewer pipe?

Under IPC Table 704.1, 6-inch pipe can be installed at a minimum slope of 1/16 inch per foot (0.52% grade, or 1 inch drop per 16 feet) provided self-scouring velocity of 2.0 ft/s is maintained.

Q2 How much drop does a 6" pipe need over 100 feet?

At 1/16" per foot, 100 feet requires 6.25 inches (158.7 mm) of total drop. At 1/8" per foot, it requires 12.5 inches.

6" Drain Pipe Fall vs. Run Length Chart

IPC & UPC Code Rules for 6" Sanitary Piping

Primary Fixtures Connected to 6" Drains:

Compare Slope Requirements for Other Pipe Sizes

6" Drain Pipe Slope FAQs

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