Pipe Slope Calculator

One-time purchase. No subscription, no ads, no account. Pipe Slope Calculator is a fast, reliable plumbing calculator for 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. Calculate drainage pipe slope and grade, check it against the plumbing code, plan a multi-segment run, and keep every job's numbers, notes and photos in one place. Works 100% offline. 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. FOUR PLUMBING CALCULATOR MODES Find Slope Enter pipe length and drop to calculate the drainage slope or pipe grade. Find Drop Enter pipe length and slope to calculate the total drop required. Find Run Enter the fall you have and the slope you need to get the longest run, with a hint when a larger pipe would meet code. Elevations Enter the start invert, run and slope to get the end invert, and check it against the sewer main. Instant results include: • Total drop • Pipe slope in in/ft, mm/m, percent, ratio (1:48) and degrees • Code compliance status with the clause it comes from (IPC Table 704.1, UPC 708.1, NPC 2.4.8.1 or Table 2.4.10.6.-C) • Set-out numbers: block height under your level, fall over a string line, and pipe laser grade • Press and hold any result to see how it was worked out • A live pipe diagram that updates as you type MULTI-SEGMENT RUNS Build a run from up to 15 straight segments, each at its own slope. The station table lists the distance, drop and invert at every station, and flags any segment below code. Start a run from any result with one tap. JOBS, NOTES AND PHOTOS Group calculations and runs by job, with the site address, permit number and notes. Take photos of the bedding, a test or the finished grade and add captions. Share one job report as a PDF: a cover page, a page for each calculation and run, then the photos. SHARE A REPORT Share a one-page PDF report for any result, with the verdict, the code clause, every slope format, set-out numbers, how you checked the slope and your notes. Or share it as an image or as text. MEASURE PIPE SLOPE WITH YOUR PHONE Turn your iPhone into a digital torpedo level. Place it along the pipe to read the slope in real time. Calibrate it in two steps, see which way the pipe falls, and lock a steady reading. Set a target slope and the display turns green when you hit it, then send the reading to the calculator with one tap. Note: Device sensors are approximate (±1–2°, about ±0.2–0.4 in/ft). Always verify slope with a calibrated level for code compliance. SUPPORTS MAJOR 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 flags slopes that fall below the minimum for your pipe size. STANDARD DRAINAGE PIPE SIZES 1½", 2", 2½", 3", 4", 5", 6", 8", 10", 12" and 15", each with its metric DN equivalent. IMPERIAL OR METRIC Switch between imperial and metric at any time. Type lengths the way you read a tape: 12' 6½", with fractions one tap away above the keyboard. Enter slopes in in/ft, mm/m, percent, ratio or degrees. COMMON SLOPE PRESETS 1/16", ⅛", 3/16", ¼", ⅜", ½", ¾" and 1" per foot, or the metric ratios on your drawings from 1:40 to 1:200. Or set any slope with the slider. BUILT FOR THE JOB SITE • Works 100% offline • No account, subscription or ads • In English and French (Canada) • Haptic feedback for quick confirmation • Dark mode support • Built for iPhone and iPad, portrait or landscape PRIVACY FIRST Pipe Slope Calculator collects zero personal information. No analytics. No crash tracking. No advertising SDKs. Calculations, jobs, notes and photos stay on your device unless you share a report.