Pipe Slope Calculator

Pipe Slope Calculator is a fast, reliable plumbing calculator for determining pipe slope, pipe fall, drainage slope, and total drop. Built for plumbers, pipefitters, contractors, and inspectors who need accurate slope calculations on the job site. Instantly calculate drainage pipe slope and pipe grade, verify plumbing code compliance, or measure slope directly using your iPhone’s built-in sensor. Works 100% offline. No account. No ads. Stop second-guessing your grade. Whether you're roughing in a 4" main line or checking the slope of an existing run, Pipe Slope Calculator gives you the right answer in seconds — before you set the pipe. MEASURE PIPE SLOPE WITH YOUR PHONE Turn your iPhone into a digital torpedo level. Place it along the pipe to measure pipe slope or pipe fall in real time. • Inches per foot (in/ft) • Millimeters per meter (mm/m) Set a target slope to display a visual reference line. When your measured slope matches the target, the display turns green. Capture the reading and send it directly into the plumbing calculator with one tap. Note: Device sensors are approximate (±1–2° / ±0.2 in/ft). Always verify slope with a calibrated level for code compliance. SUPPORTS MAJOR PLUMBING CODES Pipe Slope Calculator includes the major North American plumbing codes: • IPC — International Plumbing Code (2024) • UPC — Uniform Plumbing Code (2024) • NPC — National Plumbing Code of Canada (2020) Select your governing plumbing code and the app automatically flags slopes that fall below the minimum required for your pipe size. TWO PLUMBING CALCULATOR MODES Find Pipe Slope Enter pipe length and drop to calculate the drainage slope or pipe grade. Find Pipe Drop Enter pipe length and slope to calculate the total drop required. Instant results include: • Total drop • Pipe slope (in/ft or mm/m) • Slope percentage • Code compliance status Copy all results to the clipboard with one tap. A live animated pipe diagram updates in real time to visualize the pipe grade as you adjust inputs. STANDARD DRAINAGE PIPE SIZES Supports common plumbing pipe sizes: 1½", 2", 2½", 3", 4", 5", 6", 8", 10", 12", 15" Each pipe size shows both imperial and metric DN equivalents, making the calculator useful for mixed-unit job sites. IMPERIAL OR METRIC Switch instantly between imperial and metric units. All inputs, sliders, and results update automatically. COMMON DRAINAGE SLOPE PRESETS Quickly select the most common plumbing slopes: • 1/16" per foot • ⅛" per foot • 3/16" per foot • ¼" per foot • ⅜" per foot • ½" per foot • ¾" per foot • 1" per foot Or set any custom pipe slope using the slider. SAVE YOUR CALCULATIONS Save up to 50 plumbing calculations with optional titles. • Restore previous jobs instantly • Delete individual entries or clear all • Stored locally on your device BUILT FOR THE JOB SITE • Works 100% offline • No account, subscription, or ads • Built-in pipe slope measurement • Haptic feedback for quick confirmation • Dark mode support • Optimized for iPhone PRIVACY FIRST Pipe Slope Calculator collects zero personal information. No analytics. No crash tracking. No advertising SDKs. All calculations and history stay on your device only. Download Pipe Slope Calculator and calculate pipe slope, pipe fall, and drainage grade with confidence on your next plumbing installation.