Drain Slope Pro - Plumber

The fastest drain slope calculator built for licensed plumbers.

FIND MINIMUM DROP REQUIRED
Enter pipe diameter and run length — Drain Slope Pro instantly tells you the minimum drop to meet IPC 2021. Know the number before you rough in.

VERIFY ANY SLOPE
Enter your pipe specs and slope, hit Calculate, and get immediate pass/fail compliance with total fall, IPC status, and margin.

IPC 2021 COMPLIANCE
Every result references IPC 2021, Table 704.1.

OUTLET ELEVATION CALCULATOR
Enter inlet elevation above finished floor — get exact outlet elevation. Eliminates field math during rough-in.

FRACTION DISPLAY
All slopes display as fractions: ⅛"/ft · ¼"/ft · ⅜"/ft · ½"/ft.

WORKS OFFLINE
All IPC tables embedded. No internet. No account.

ONE-TIME PURCHASE — $1.99
Unlock unlimited calculations. No subscription.

A FieldMetric tool.
IPC 2021 · Table 704.1
≤3" pipe = ¼"/ft min · ≥4" pipe = ⅛"/ft min