User manual

How CalculationX apps work

This guide explains the normal workflow for each CalculationX app, what the main inputs mean, and how to save, import, export, and report your work.

xP
XPipe
Pipe networks
xD
XDuct
Duct systems
xF
XFrame
Steel frames
xPs
XPsych
Psychrometrics
xH
XHeat
Heat exchangers
Pl
Plinth
Planning
Mo
MatOffer Pro
Procurement

Basics

CalculationX is a browser workspace for engineering calculations. Each app follows the same rhythm: define inputs, build a model or process, run the calculation, review results, then save or export the project.

Open an appUse the dashboard cards or app list. The CX logo in each app returns to the dashboard.
Enter model dataUse the left panel or toolbar for fluids, geometry, loads, states, and project information.
CalculateRun the app-specific calculate, analyze, or apply command. Results appear in the right panel, chart, canvas, or report view.
Save, export, or reportCloud Save stores the editable project in your account. Export Project downloads an editable file for backup or transfer. PDF Report creates printable documentation.

Account, access, and plans

Every app shares one CalculationX account, one Free/Pro plan, and (in Plinth) the same workspace roles and invitations.

Sign in and profile

  • Sign in with email/password or Google from the sign-in page.
  • Use "Forgot password?" on sign-in to reset a forgotten password by email.
  • Open Profile from the dashboard account menu to update your display name, change your password, and see your plan and usage.
  • Profile also has a permanent "Delete my account" option, which removes your account and its data.

Free and Pro plans

  • Every account starts on the Free plan, no credit card required.
  • Free includes a limited number of saved calculations per month in XPipe, XDuct, XFrame, XPsych, and XHeat, plus reduced limits in Plinth and MatOffer Pro (see each app's section below).
  • Pro removes those limits and adds private support tickets. Upgrade from the dashboard or Profile page.
  • Need help beyond this guide? Use Support in the top navigation to open your ticket list or start a new ticket.
Plinth workspace roles: Owner and Admin can invite or remove workspace members, change member roles, and manage workspace-wide sharing. Members can open boards shared with them but can't manage other people's access. A board's creator can also manage that specific board's settings and invite people directly to it, independent of workspace role.

Saving and files

Cloud Save

  • Cloud saves are tied to your signed-in CalculationX account.
  • History or board panels list saved calculations and let you reopen them.
  • Calculation app Cloud Save buttons usually become active after a successful calculation.

Export Project

  • XPipe exports .cxpipe project files.
  • XDuct exports .cxduct project files.
  • XFrame exports .fec3 project files.
  • XPsych exports .cxpsych project files.
  • Import Project opens one of these editable files and replaces the current model after confirmation.
Use Cloud Save for account storage, Export Project for an editable file on the user's PC, and PDF Report for printable non-editable documentation. Import Project replaces the current project, so export a backup first if the current model has unsaved changes.
xPXPipe v2

XPipe - pipe pressure drop

XPipe calculates pipe pressure drop for fluid networks. It uses fluid properties, pipe material and size, flow, length, fittings, and components to calculate total pressure loss and identify the critical path.

Select units and fluidChoose SI or Imperial, then pick water, glycol mixture, temperature, and open or closed system type.
Define source and sink nodesUse source for the high-pressure side and sink for the lowest pressure or return point.
Add pipe segmentsEnter from/to nodes, flow, length, material, nominal size, and fittings such as valves, elbows, tees, reducers, entrances, or exits.
Add equipment componentsUse the component tab for coils, chillers, boilers, balancing valves, flow control valves, or custom pressure-drop items.
CalculateReview segment pressure drop, fitting loss, velocity, total loss, and critical path highlighting.
Free plan: a limited number of saved calculations each month. Pro removes the limit.
xDXDuct v2.0

XDuct - duct pressure drop

XDuct builds a duct network from segments and fittings. It supports round and rectangular ducts, predefined air/flue-gas fluids, custom density and viscosity, roughness presets, ASHRAE fitting data, chart export, and critical path results.

Set units and fluidChoose SI or IP, then select standard air, humid air, flue gas, or custom fluid properties.
Add duct segmentsEnter from/to nodes, shape, size, length, flow, roughness, and fittings. Use source and sink nodes to define the path to evaluate.
Use fitting searchFilter ASHRAE fittings by category, shape, and text, then enter the required geometry inputs for the selected fitting.
CalculateThe network view marks the critical path. Results show segment loss, fitting loss, velocity, Reynolds behavior, and total path pressure drop.
Export viewsUse PDF for the full calculation report or Chart for a PNG/PDF of the network view.
Free plan: a limited number of saved calculations each month. Pro removes the limit.
xFXFrame v3

XFrame - steel frame analysis

XFrame models steel members, supports, and loads for 2D or 3D frame analysis. It includes example models, member force diagrams, load combinations, equilibrium checks, section libraries, and design/report dialogs.

Start from an example or blank modelExamples include simple beams, cantilevers, portal frames, multi-storey frames, 3D frames, and trusses.
Create nodes and elementsAdd nodes in the canvas, connect elements, then choose beam or truss behavior and a steel section such as IPE, HEA, HEB, W, UPN, SHS, RHS, CHS, or custom.
Apply supports and loadsSupports include fixed, pinned, rollers, springs, and custom DOFs. Loads include nodal loads, UDL, VDL, point loads on elements, temperature, and self-weight.
Analyze and reviewReview reactions, displacements, axial force, shear, bending moment, torsion, utilization, and equilibrium checks.
Export the project or reportExport Project downloads an editable .fec3 model. PDF Report creates a printable report from selected sections.
Free plan: a limited number of saved calculations each month. Pro removes the limit.
xPsXPsych v1.0

XPsych - psychrometric analysis

XPsych resolves HVAC air states and processes on a dry-bulb versus humidity-ratio chart. It works in SI units and supports single-stream and two-stream air-side processes.

Resolve the inlet stateEnter pressure, dry-bulb temperature, and one humidity input: RH, humidity ratio, dew point, or wet-bulb.
Choose a processProcesses include sensible heating/cooling, cooling coils, evaporative cooling, steam humidification, spray humidifier, reheat, pressure change, zone SHR, mixing, heat exchangers, and ventilation mixing.
Add process parametersEnter target temperature, delta T, bypass factor, effectiveness, steam rate, SHR, second stream properties, or target mix temperature depending on the process.
Apply and chainApply the process to create an outlet state. Chain the outlet into the next inlet to build an HVAC process path.
Use the chartToggle enthalpy, wet-bulb, and specific volume layers. Light mode helps when exporting or presenting chart views.
Free plan: a limited number of saved calculations each month. Pro removes the limit.
xHXHeat v1.0

XHeat - plate heat exchanger sizing

XHeat is a preliminary sizing and performance estimator for plate heat exchangers, covering MEG/water duties on both sides. It works the way an engineer would check a PHE by hand: duty and LMTD first, then geometry-based U, plate count, and pressure drop, with every assumption visible and editable.

Hierarchy: the Design & sizing tab solves duty/outlet temperatures and sizes a plate count and area from process conditions and a chosen U method. The Performance check tab is independent - it takes a fixed plate count, area, and U (e.g. a supplier datasheet) and predicts outlet temperatures and duty for given inlet conditions.
Enter process conditionsSet hot and cold MEG concentration, flows, and temperatures. Mark exactly one unknown value per side with [calc] - or duty - and XHeat solves the rest.
Choose a U methodGeometry based iterates plate count and U from plate gap, width, length, chevron angle, and correlation constants. Recommended range, manual U, and vendor calibration are also available.
Set plate geometryAdjust gap, width, length, area enlargement, ports, passes, and channel allocation. Aplate and length stay consistent with each other unless you switch to a vendor/manual override.
Calculate and reviewCalculate produces duty, LMTD/F, selected area and plate count, U and film coefficients, pressure drop, and a confidence score against energy balance, correlation range, and hydraulic limits.
Save, export, and reportSign in to cloud save, review past calculations from History, export/import an editable .cxheat project file, or generate a PDF report of the full calculation summary.
Free plan: a limited number of saved calculations each month. Pro removes the limit.
PlPlinth v1.0

Plinth - project planning

Plinth organizes engineering delivery work around workspaces, boards, tasks, assignees, task groups, workflow statuses, dates, dependencies, and progress. It is useful for project planning, calculation checklists, submittal tracking, and coordination follow-up.

Hierarchy: a workspace is the company or project area, a board is one project plan inside that workspace, board members are people invited directly to that board, and task groups are work categories inside the board.
Choose a viewUse List for scanning, Kanban for status flow, Calendar for date review, Gantt for schedule and dependency planning, and Progress for workload and risk review.
Create and edit tasksAdd tasks from the top button or quick entry. Open a task drawer to edit title, description, dates, status, priority, assignee, tags, task group, comments, and dependencies.
Track progress and blockersDependencies show which tasks must finish before another task can move forward. The Progress view summarizes completion, workload, due work, overdue tasks, and blocked items.
Filter the boardUse status, assignee, task group, grouping, and search controls to narrow the active task list without deleting hidden tasks.
Save, report, and shareSign in to save cloud boards, invite board members directly, assign a board to a workspace, and export PDF progress reports for meetings.
Free plan: 1 board, with no board or workspace sharing/invites. Pro removes both limits.
MoMatOffer Pro

MatOffer Pro - procurement

MatOffer Pro is a full procurement workspace built around suppliers, materials, RFQs, supplier offers, bills of materials, and compliance. It is built for engineering purchasing teams running real supply chains, not a lightweight quote tracker - pricing, tax, shipping, currency, lead time, and compliance are all tracked at the individual line-item level.

Hierarchy: an RFQ defines what suppliers should quote, with per-material compliance requirements and target prices. Each Offer is one supplier's response to that scope (or a standalone quote), with its own line-level currency, pricing, tax, shipping, lead time, and compliance evaluation. The BOM tracks what a project actually needs against what has been quoted, approved, and ordered, so coverage gaps are visible before they become delays.
Set up suppliers and materialsBuild your supplier directory with capabilities, certifications, and performance scores, and your material library with compliance requirements and preferred suppliers.
Create an RFQScope the materials, quantities, and target prices suppliers should quote, attach per-material compliance requirements, and list the target suppliers.
Capture supplier offersLink an RFQ to pre-load its scope, or add lines manually. Each line has its own currency with live ECB exchange rates, discounts, tax, shipping, lead time, incoterm, and compliance status.
Compare and approveUse Price Compare for side-by-side supplier quotes on any material, then approve or reject pending offers from the Approvals queue.
Track the BOM and act on insightsAssign materials to project BOM groups to see procurement coverage and gap status update automatically, and check Intelligence for currency exposure, volume-discount analysis, and sourcing recommendations.
Free plan: up to 3 suppliers, 5 materials, and 1 active RFQ (Draft or Issued) at a time. Pro removes all three limits.

Reports

Project info

  • Use the Info button to set project name, number, client, company, engineer, date, and notes where available.
  • These fields are stored in project files and included in reports.

PDF behavior

  • Most reports open a print-ready browser window.
  • If nothing opens, allow pop-ups for CalculationX and try again.
  • Use your browser print dialog to save as PDF when needed.

Keyboard shortcuts

Most apps are mouse and toolbar first, but XFrame and Plinth support keyboard shortcuts for faster editing. Shortcuts are disabled while typing in a text field.

XFrame

  • Ctrl/Cmd+Z undo, Ctrl/Cmd+Y or Ctrl/Cmd+Shift+Z redo.
  • F fits the view to the current model.
  • Delete or Backspace removes the selected element, or the selected node if nothing is selected.
  • Escape cancels an in-progress add action or clears the current selection.

Plinth

  • N creates a new task.
  • G switches to the Gantt view.
  • / focuses the search box.
  • Enter confirms an inline edit such as a column rename or tag; Escape cancels it.
XPipe's Save dialog supports Enter to confirm and Escape to cancel. XDuct, XPsych, and MatOffer Pro don't have dedicated keyboard shortcuts yet, beyond pressing Enter to add a row in small forms.

Troubleshooting common messages

Most error messages explain what to do next on their own, but a few are worth knowing about in advance.

  • "Please sign in to calculate," or an unexpected jump to the sign-in page: your session expired. Sign in again - XPipe, XFrame, and MatOffer Pro show a message first, while XDuct, XPsych, and XHeat redirect directly.
  • "Failed to load library. Please refresh.": XPipe couldn't load a required library, usually a brief network hiccup or an ad-blocker. Refresh the page.
  • A PDF or report doesn't open: it's likely a blocked pop-up. Allow pop-ups for calculationx.com in your browser, then run the export again.
  • "Not an XPipe/XDuct/XPsych/XHeat project file" or "Invalid .fec3 file": Import Project only accepts files exported from that same app (.cxpipe, .cxduct, .cxpsych, .cxheat, .fec3). Re-export the file if it was edited outside the app.
  • "This file does not appear to be a valid MatOffer Pro backup": only import files that were exported from MatOffer Pro's own Export function.
  • A free-plan limit message about calculations, boards, suppliers, materials, or RFQs: you've reached that app's free-tier limit for now. Upgrade to Pro to remove it, or contact orders@calculationx.com.
  • "Add at least one segment/support" or a required-field error: the model or form is missing something the calculation needs. Check the referenced panel, fill it in, and try again.
  • "That would create a circular dependency" in Plinth: the dependency you're adding would make two tasks depend on each other, directly or through a chain. Remove one side of the loop first.
  • "Cannot delete ... it is linked to/referenced by ..." in MatOffer Pro: remove the link (for example, unlink the offer or BOM reference) before deleting the supplier, material, or RFQ.

Good checks before using results

  • Confirm the selected unit system before entering dimensions or flows.
  • Check source and sink nodes for XPipe and XDuct before calculating critical path results.
  • Look for unrealistic velocity, pressure drop, humidity, or displacement values after each calculation.
  • For XFrame, verify supports restrain rigid-body movement and load directions match the intended global or local axes.
  • For XHeat, treat geometry-based U as an estimator - confirm Reynolds number, channel velocity, and the confidence score before relying on a sizing result.
  • For Plinth, review dependencies and date ranges before relying on a schedule view.
  • For MatOffer Pro, confirm exchange rates and compliance status on every offer line before approving, and recheck BOM gap status after adding new offers.
  • Export an editable project file before major edits or imports.
CalculationX helps organize and calculate engineering models, but final engineering judgment, code compliance, and design responsibility remain with the user.