10 Best Plumbing Design Software of 2026

Revit ranks first because it is where most coordinated building projects are modeled, and plumbing is designed in the same model as the walls, slabs and ductwork it has to clear. Autodesk describes Revit for MEP engineering as a place to design, model and document building systems in the context of a full building information model, with interference detection early in design. For contractors, Autodesk documents a path from a Revit model to Fabrication CADmep for shop drawings and to Fabrication ESTmep for estimates, and Revit itself includes tools that automate the fabrication model layout. The tradeoffs are price and breadth. At $251 a month it is the most expensive verified option here, and much of what you pay for serves architects and structural engineers. Firms that only need code-based pipe sizing will still want a dedicated calculator, or an add-in such as MagiCAD Piping or AquaBIM on top.

h2x is the most plumbing-focused design tool on this list. You place pipes and components, connect them, and the software runs the sizing. For domestic water it automates flow rate calculations, pipe sizing and pressure balancing, and h2x says those calculations are verified by CIBSE standards and aligned with ASHRAE methods. For wastewater it automates fixture loading, pipe sizing and gradient checks. Drawings and reports update as the design changes, and the output can be a custom PDF drawing set, a CAD file mapped to your templates or a Revit model, plus a calculation report and a bill of materials. The same product also covers stormwater, gas, fire protection and HVAC. The company reports more than 5,000 paying users and 140,000 designs completed. The main gap for buyers is price, which is quote only, so we scored value conservatively. US engineers should also confirm how it handles their local plumbing code during a trial.

S-Pipe does one job: it computes pipe sizes for hot and cold domestic water supply in residential and commercial buildings, with a virtually unlimited number of pipes. You enter each pipe section by its start and end node, pipe type, length, fittings and fixtures, and S-Pipe picks the smallest size that stays within your maximum velocity and maximum pressure drop per 100 feet, using the Hazen-Williams equation. It follows ASHRAE and ASPE procedures, supports codes such as UPC and IPC, and lets you use the Hunter GPM curve or your own. Reports list GPM flow, velocity and pressure loss for each section, plus a bill of materials with labor. At $499 once, it is the cheapest code-based supply sizing tool we found with a published price. The limits are that it does not draw, and its drawing link only works with old 32-bit AutoCAD MEP releases, so most users will key the system in by hand.

AutoCAD remains the default drafting tool for plumbing plans, risers and details, and the MEP toolset is included with AutoCAD 2027 at no extra cost. It adds a library of more than 10,500 intelligent MEP objects that represent real components in mechanical, electrical and plumbing systems, plus MEP workspaces with their own palettes and ribbons. Autodesk claims the toolset raises productivity on common MEP tasks by up to 85%, a figure from its own study. At $175 a month it costs less than Revit, and DWG is still the format many contractors, plan reviewers and smaller engineering firms exchange. What it does not do is size pipes to code or coordinate a full 3D building model, so plumbing designers usually pair it with a calculator such as Elite S-Pipe and D-Pipe. Firms moving to BIM deliverables will outgrow it.

D-Pipe is the drainage partner to S-Pipe. It calculates pipe and vent sizes for sanitary building drain systems with a virtually unlimited number of sections, sizing branch, sewer and stack pipes and branch and stack vents according to UPC or IPC. It follows the ASPE Databook, and you can define as many custom sizing code files as you need for local amendments. Each section takes a node pair, a type, length, material, fittings and connected fixtures, or you can enter a DFU value directly. Reports cover project data, pipe sizes, vent sizes and a bill of materials with labor and material cost. At $299 once it is the cheapest code-based drainage sizing tool we found. As with S-Pipe, it does not draw, and its CAD link only supports old 32-bit AutoCAD MEP versions, so plan on entering the system by hand.

QuickPlumb is built for the plumbing contractor rather than the consulting engineer. You import an image of the plan, place fixtures, and the software connects pipes to fixtures and recognizes fittings automatically. From that layout it produces a bill of materials, an estimate, a pipe cut list meant to reduce waste and a 3D isometric drawing, and it sizes water distribution pipes. Material lists can be uploaded to get quotes and place orders. Epiphany Software, based in Wilmington, North Carolina, says many of its staff have plumbing design backgrounds. At $29 a month with a 30-day trial, QuickPlumb is the least expensive subscription on this list. It does not document drainage sizing to UPC or IPC, BIM output or a Revit link, so engineers producing stamped design documents will need one of the tools ranked above it.

MagiCAD Piping adds design and calculation tools to Revit, AutoCAD and BricsCAD for heating, cooling and domestic water systems, including drainage, sprinkler and specialist systems. Instead of exporting to a separate calculator, you size the pipework inside the model with integrated piping calculations, pipe series functions and pipe drawing tools. The Revit version adds gas system design and calculation and connection nodes between models. MagiCAD Cloud gives access to manufacturer BIM objects and product selection tools, so you can design with real products. MagiCAD Group localizes the software to the standards of different countries, which is useful for firms working across borders, though US buyers should confirm which plumbing code settings are available. MagiCAD does not publish prices, so you ask for a quote, and you also need a host CAD license. That pushes its value score down despite strong features.

AquaBIM takes a different approach from the other tools here. It is a Revit add-in that connects an AI assistant, such as Claude, to the open Revit model and gives it real Revit tools. You describe the work in plain language and it creates domestic water and sanitary runs on real Revit pipe, ties lavatories, water closets and equipment into the right system, points out disconnected fixtures and gaps, and reroutes or resizes piping. A dedicated license is $50 a month or $500 a year, and a floating license shared across a team is $2,000 per seat a year. There is a 14-day trial with no credit card. The limits are clear on Design Master's own page: fixture unit counts, pipe and vent sizing, pressure and flow and code compliance are listed as things users can request for future versions, so today it speeds up modeling rather than engineering calculations. It also needs a Revit seat.

OpenBuildings Designer is Bentley's answer to Revit: a multidisciplinary BIM application for designing, documenting and simulating buildings. Its mechanical tools parametrically model HVAC, piping and plumbing systems, automatically model components, paths and angles when you complete piping connections, and size water, heating, cooling and gas systems with CIBSE-compliant algorithms. It also includes building energy simulation and exchanges IFC, RFA and DWG data, so it can work alongside Revit-based consultants. A 12-month Virtuoso subscription includes one license and two Keys that can be redeemed for training or services. Bentley's page showed us a price in Polish zloty only, so the US price is pending and value is scored conservatively. For US plumbing engineers the main questions are code support, since the sizing references CIBSE, and whether project partners will accept Bentley files.

SysQue sits at the end of the plumbing design process, where a contractor turns an engineer's model into something that can be built and prefabricated. It runs inside Revit and replaces generic families with real content from a database of over eight million parts based on actual manufacturer products, across electrical, piping, mechanical and sheet metal. Detailers can reach LOD 400, output piping, plumbing or ductwork spool sheets for prefabrication, lay out hangers and send them to Trimble Field Link, and export pipe CAM files to PypeServer. With the VDC Pro+ subscription the model can also feed estimating. Trimble does not publish a price, so value is scored conservatively. It ranks last here only because it is not a design tool in the engineering sense: it does not size systems, and it is wasted on a firm that does not fabricate.