Engineering calculations, documented as you work.

ILX Calcs is a unit-aware engineering calculation platform for Windows. It combines a live, dimensionally-tracked math engine with formatted narrative, symbolic equation display, a built-in materials and section database, and a library of more than thirty structural calculation templates. The result is a document that reads like a textbook hand-calc — equations shown symbolically, then evaluated numerically with units — but recalculates instantly whenever you change an input. Documents are saved with the .ilxw extension and flow directly to ILX PDF and the ILXReport standard.

The defining feature is that every quantity carries its units. When you define a beam span as 24 ft and a load as 2 kip/ft, the engine knows the moment w·L²/8 comes out in kip·ft, automatically converts wherever needed, and refuses to add a length to a force. Unit mistakes — the single most common source of calculation error — are caught at the moment of input rather than discovered in review.

Why unit-aware? A spreadsheet happily lets you add a stress in ksi to a pressure in psf and produces a confident, wrong answer. ILX Calcs treats units as first-class data: dimensional consistency is enforced on every operation, conversions are automatic, and the displayed result always shows the unit so a reviewer can verify it at a glance.

ILX Calcs is part of the ILX Suite. Any sheet or package of sheets exports to ILX PDF, and individual calculation blocks can be copied as ILXReport blocks to assemble a coordinated calculation package alongside output from the other ILX tools. Revision tracking with date, engineer, and notes is built in, so the calculation record is audit-ready.

Your first workflow looks like this:

1. Launch ILX Calcs and create a new sheet with Ctrl+N.
2. From the Insert tab, add a Section Heading and a Text Block describing the calculation.
3. Insert Variables for your inputs, each with a value and a unit.
4. Insert Formula cells that reference those variables by name; the engine shows the symbolic form and the evaluated result with units.
5. Save the sheet (Ctrl+S) and export to ILX PDF from the Export tab.

ILX Calcs is a native Windows desktop application. The live recalculation engine is lightweight, so requirements are modest, but large multi-sheet packages with many embedded images benefit from more RAM and a faster CPU.

Component	Minimum	Recommended
Operating System	Windows 10 64-bit (21H2)	Windows 11 64-bit (23H2 or later)
CPU	Dual-core 2.0 GHz	Quad-core 3.0 GHz or better
RAM	4 GB	8 GB or more
GPU	DirectX 11 integrated graphics	Integrated graphics (no discrete GPU required)
Storage	1 GB free	2 GB free on SSD
Display	1366 × 768	1920 × 1080 or higher, 100% scaling

Note: ILX Calcs renders crisp equation typography that scales with your display. On high-DPI monitors set Windows scaling to 100% or 125% for the sharpest symbolic equation display. A .NET 8 runtime is installed automatically by the setup package if it is not already present.

Install ILX Calcs as follows:

1. Download ILX-Calcs-Setup-1.4.exe from your ILX Studio account portal.
2. Right-click the installer and choose Run as administrator.
3. Accept the license agreement and choose an install location (default C:\Program Files\ILX Studio\Calcs).
4. The installer registers the .ilxw file association and the template library.
5. Launch the application and sign in with your ILX Studio credentials to activate your seat.

Licensing is seat-based. Each engineer signs in with their ILX Studio account, checking out a seat to that machine. Manage active seats — release a seat from a retired computer or move one to a new workstation — from Account → Seats in the application or through the my.ilxstudio.com admin portal. A seat permits installation on a primary and a secondary machine for the same engineer, with one active session at a time.

Updates arrive through the in-app updater. When a build is published, a banner appears on the Home tab; choosing Install Update downloads the patch, closes the application, applies it, and relaunches. Template library updates are delivered the same way, so new templates appear automatically. Opt into preview builds under Settings → Updates → Channel.

To create a new calculation sheet:

1. Choose Home → New or press Ctrl+N.
2. In the New Sheet dialog, enter the sheet title, project name, and project number.
3. Select the unit system — US Customary or SI — which sets the default display units for new variables.
4. Confirm the engineer and firm info (pulled from Settings) for the title block.
5. Click Create. A blank sheet opens with the title block populated.
6. Save with Ctrl+S; the sheet is written as a single .ilxw file.

To open an existing sheet, choose Home → Open or double-click any .ilxw file in Windows Explorer. Recently opened sheets appear on the start screen and under Home → Recent. A sheet is fully portable: everything — variable definitions, formulas, narrative, embedded images, code references, and the revision history — lives inside the .ilxw file, so a reviewer who opens it sees the live, recalculating document exactly as you authored it. Alternatively, start from a template (Chapter 10) rather than a blank sheet to get a fully worked calculation you can adapt.

ILX Calcs uses a ribbon interface. The tabs group the actions you take while authoring a calculation: inserting content, choosing templates, managing units, opening the constants database, and exporting.

Ribbon Tab	Contents
Home	New, Open, Save, Save As, Undo / Redo, Print
Insert	Variable, Formula, Text Block, Image, Code Ref, Section Heading, Table
Templates	Browse library, open template, save as template
Units	Set unit system (US Customary / SI), manage unit definitions
Constants	Open constants panel (materials, sections, ASCE 7 maps)
Export	Export to PDF, Export to ILX PDF Package, Copy as ILXReport block
Settings	Firm info, engineer, unit preferences, display

The central canvas is the calculation document itself — a continuous, scrollable page that flows like a word processor but where formula and variable cells live as active objects. Click any cell to edit it in place; the symbolic rendering updates as you type. Drag cells to reorder, and use Ctrl+Enter to commit a formula. The canvas paginates for print and PDF export so you can see exactly where page breaks will fall.

The properties panel on the right edits the selected cell. For a variable it shows the name, value, display unit, and description; for a formula it shows the expression, the result unit override, the number of significant figures, and whether to display the symbolic substitution step. The constants panel (opened from the Constants tab) docks alongside and lets you drag a material property or section property directly into a formula as a referenced value.

The math engine is the core of ILX Calcs. Every value is stored as a magnitude paired with a dimension, and every operation checks dimensional consistency. The engine supports the full set of engineering dimensions and their derived units, and converts automatically between any compatible units within an expression.

Capability	Behavior
Dimensional tracking	Every quantity carries length, force, time, etc.; results inherit the correct derived unit
Automatic conversion	Mixing ft and in, or kip and lb, in one expression converts silently and correctly
Input-time error catching	Adding incompatible dimensions (force + length) is flagged immediately, not after the fact
Display unit control	Force any result into a preferred unit (e.g., show a moment in kip·ft regardless of input units)
Significant figures	Per-cell control of displayed precision without affecting stored precision

For example, if you define L = 24 ft, w = 2 kip/ft, and write the formula M = w*L^2/8, the engine evaluates the magnitude and reports M = 144 kip·ft — the unit is derived, not assumed. If you instead wrote M = w + L, the engine immediately marks the cell with a dimensional-error badge because force per length cannot be added to length. This input-time enforcement is what eliminates the silent unit blunders that plague spreadsheet calculations.

The engine also recognizes named physical constants and supports trigonometric, logarithmic, and power functions with proper dimensional handling (for instance, the argument of a logarithm must be dimensionless, and the engine enforces it).

A calculation is built from a small set of cell types, all inserted from the Insert tab. Together they let you mix computation and explanation in one continuous document.

Cell Type	Purpose
Variable	A named value with a unit, referenced by name elsewhere
Formula	Symbolic expression shown like a textbook, then evaluated with units
Text Block	Formatted narrative paragraphs with bold, italic, lists
Section Heading	Numbered or unnumbered headings that structure the sheet
Image	Embedded diagrams, sketches, or photos
Code Ref	A cited code clause that anchors a formula to its source
Table	Tabulated data or summary of results

To build a calculation:

1. Insert a Section Heading to title the calculation step.
2. Insert Variables for each input — give each a clear name, a value, a unit, and a short description.
3. Insert a Formula and type the expression referencing your variable names; the engine renders the symbolic form, the substituted-values step (optional), and the unit-bearing result.
4. Add a Text Block to explain assumptions, and a Code Ref to cite the governing clause.
5. Add an Image for a free-body diagram if helpful.

Because formulas reference variables by name, the calculation reads naturally and stays self-documenting. Renaming a variable updates every formula that references it, and a reference to an undefined or deleted variable is flagged so broken links never go unnoticed.

The constants panel, opened from the Constants tab, puts a built-in engineering reference at your fingertips. Rather than looking up a yield strength or a section modulus and re-typing it, you drag the value directly into a formula as a referenced quantity that carries its units and remembers its source.

Category	Contents
Steel materials	A992, A36, and other grades — Fy, Fu, E, modulus
Concrete	f′c presets, unit weight, modulus of elasticity
Wood (NDS)	Lumber species design values by grade
Steel sections	W-shapes, HSS, and pipe section property database
ASCE 7 maps	Wind, seismic, and snow mapped parameters

To use a constant or section property:

1. Open the Constants tab and choose a category.
2. Search or browse for the material or section (for example a W18×50 or steel grade A992).
3. Drag the desired property — section modulus S_x, area A, yield strength F_y — into a variable or formula cell.
4. The value is inserted with its correct unit and a note of its source, so the citation appears in the report.

Selecting a section also exposes its full property set (A, I_x, I_y, S_x, S_y, Z_x, Z_y, r_x, r_y, J, and more), all available to reference by name from your formulas.

Every sheet is a live dependency graph. When you change the value or unit of any variable, the engine identifies every formula that depends on it — directly or transitively — and recomputes only those, propagating the change through the entire sheet instantly. There is no recalculate button to remember and no stale results to worry about: what you see is always consistent with the current inputs.

This makes ILX Calcs ideal for design iteration. Bump a beam span, swap a section from the database, or change a load factor, and the moment, the stress ratio, the deflection, and the final pass/fail verdict all update at once. Because the dependency graph is explicit, the engine also detects and reports circular references rather than looping forever.

To work with recalculation:

1. Build your sheet with variables and dependent formulas.
2. Edit any variable's value or unit in the properties panel.
3. Observe every dependent result update immediately; changed results briefly highlight so you can see the ripple.
4. Iterate freely — try alternative sections or loads — until the design verifies.

A built-in consistency self-test can be run from Settings → Diagnostics; it recomputes a set of reference sheets and confirms the engine reproduces their known results, guarding against any corruption of the math library.

The template library ships with more than thirty fully worked structural calculation templates spanning steel, concrete, wood, masonry, cold-formed steel, and load determination. Each template is a complete, editable sheet with the variables, formulas, code citations, and pass/fail checks already laid out — you supply your inputs and the live engine produces the verified result. Open a template from the Templates tab, and save your own customized sheets back into the library with Save as Template.

Each template enforces the limit states of its governing standard:

Discipline	Representative Limit States	Reference
Steel	Flexure, compression, shear, beam-column interaction (H1-1)	AISC 360-16
Concrete	Flexure, shear, axial-flexure (P-M), development	ACI 318-19
Wood	Bending, compression, combined, connection capacity	NDS 2018
Masonry	Flexure, shear, axial for CMU walls and lintels	TMS 402-16
Cold-formed steel	Bending, web crippling, axial for C-sections and studs	AISI S100-16
Loads	Wind, seismic base shear, snow, load combinations	ASCE 7-22

Design method note: Steel templates support both LRFD and ASD per AISC 360-16, selectable per sheet, and wood templates use ASD with NDS adjustment factors. Concrete templates use strength design (LRFD) per ACI 318-19. The active method and the governing demand-to-capacity ratio are shown at the top of each check so the verdict is unambiguous.

The steel templates implement AISC 360-16. They draw section properties directly from the W-shape, HSS, and pipe database so you select a member rather than re-typing its geometry.

Steel Template	Covers
Steel beam	Flexural strength including lateral-torsional buckling, shear
Steel column	Axial compression with flexural and torsional buckling
Beam-column interaction	Combined axial and flexure, AISC H1-1
Brace	Axial tension and compression for bracing members
Base plate	Base plate design per AISC Design Guide 1
Anchor bolts	Anchorage to concrete per ACI 318-19 Ch.17

The concrete templates implement ACI 318-19 strength design and include the P-M interaction diagram for columns.

Concrete Template	Covers
Rectangular beam	Flexure and shear design
T-beam	Flexure with effective flange width
Two-way slab	Moment distribution and reinforcement
Concrete column	Axial-flexure with the P-M interaction diagram
Spread footing	Bearing, punching/one-way shear, flexure
Shear wall	In-plane shear and flexural design

To use a template: open it from the Templates tab, replace the input variables with your project values (or drag a section from the constants panel), and read the live result. Every formula cites its AISC or ACI clause so the calculation is review-ready.

Beyond steel and concrete, the library covers wood, masonry, cold-formed steel, and the load determination that feeds every other calculation.

Discipline	Templates	Reference
Wood	Sawn lumber beam, glulam beam, wood column, beam-column, nailed/screwed lateral (Z), nailed/screwed withdrawal (W), bolted connection	NDS 2018
Masonry	CMU shear wall, masonry column, masonry lintel	TMS 402-16
Cold-formed steel	CFS beam (C-section), CFS stud, CFS connection	AISI S100-16
Loads	Wind loads (MWFRS Ch.27, C&C Ch.30), seismic base shear (ELF Ch.12), snow loads (Ch.7), load combinations	ASCE 7-22

The wood templates apply the full set of NDS 2018 adjustment factors (load duration, wet service, temperature, size, repetitive member, and so on) and pull species design values from the constants panel. Connection templates compute lateral (Z) and withdrawal (W) capacities for nailed, screwed, and bolted connections. The masonry templates follow TMS 402-16 for CMU shear walls, columns, and lintels, and the cold-formed templates follow AISI S100-16 effective-width procedures for C-section beams, studs, and connections.

The ASCE 7-22 load templates are foundational: the wind template covers both the Main Wind Force Resisting System (Chapter 27) and Components & Cladding (Chapter 30); the seismic template computes base shear by the Equivalent Lateral Force method (Chapter 12); snow follows Chapter 7; and the load-combination template assembles LRFD and ASD combinations. Mapped wind, seismic, and snow parameters are available from the ASCE 7 maps in the constants panel so the loads tie directly back to the site.

ILX Calcs tracks revisions inside the sheet. Each revision records a date, the engineer, and notes describing what changed, building an audit trail right in the .ilxw file. Add a revision when you reach a milestone or issue the calculation, and the revision table appears in the exported report so reviewers can see the document's history at a glance.

Export is handled from the Export tab. A single sheet can be exported to PDF, or a package of multiple sheets can be exported together to an ILX PDF Package with a unified cover, table of contents, and continuous pagination. Any individual calculation can also be copied as an ILXReport block and pasted into a coordinated package alongside output from the other ILX Suite tools, so a structural submittal can interleave Calcs sheets with Foundation and Structures output in one consistent document. The output conforms to the ILXReport standard for firm-wide formatting consistency.

To generate a report: choose Export → Export to PDF for a single sheet or Export to ILX PDF Package for several, set the cover and pagination options, and export. Print directly with Ctrl+P for a quick hard copy.

The Settings tab controls sheet-level and application-level preferences. Sheet-level settings (unit system, engineer, revision) are stored in the .ilxw file; application-level settings (firm info, display, updates) persist across sheets.

Setting	Location	Options
Unit system	Units tab / Settings → Units	US Customary, SI
Custom unit definitions	Units → Manage	Define and alias units
Default significant figures	Settings → Display	2–6 (per-cell override available)
Symbolic substitution step	Settings → Display	Show / hide value-substitution line in formulas
Display theme	Settings → Display	Light, Dark, System
Equation font size	Settings → Display	Adjustable for high-DPI
Firm info & logo	Settings → Firm	Name, address, logo for title block
Engineer	Settings → Firm	Default engineer for new sheets and revisions
Template library path	Settings → Templates	Built-in plus a shared firm folder
Update channel	Settings → Updates	Stable, Beta
Export defaults	Settings → Export	Cover page, pagination, ILXReport formatting

Error: Dimensional mismatch in formula. The cell tries to combine incompatible dimensions, such as adding a force to a length, or passing a dimensioned value to a function that requires a dimensionless argument. Check each term's units — the badge identifies the offending operands — and correct the variable units or the expression.

Error: Undefined variable reference. A formula references a variable name that does not exist, usually because it was renamed or deleted. Either restore the variable, or update the formula to reference the correct name; the broken reference is highlighted in the cell.

Error: Circular reference detected. Two or more formulas depend on each other so the dependency graph cannot be resolved. The engine lists the cells in the cycle; break the loop by removing one dependency or introducing an independent input.

Error: Template failed to load. The selected template could not be opened, typically because the library path is missing or a shared firm template is unavailable. Confirm the template library path under Settings → Templates, and reinstall or re-sync the firm folder if needed.

Application logs. If you need to send diagnostics to support, the full logs are written to %LOCALAPPDATA%\ILX Studio\Calcs\Logs\. Attach the most recent log file to your support request.

Appendix A — Conventions

Convention	Meaning
code	File paths, unit literals, and expressions
Ctrl+N	Keyboard shortcut
→	Menu / ribbon navigation path
Fy, Sx, f′c	Engineering symbols (yield stress, section modulus, concrete strength)
×	Section size separator (e.g., W18×50)

Appendix B — File Management

Sheets are stored as single .ilxw files containing all variables, formulas, narrative, images, code references, and revision history. Use Save As to branch a design study or adapt one calculation into another. Timed autosave snapshots protect against crashes; recovered sheets are offered on the next launch.

Appendix C — Validation

The math engine and templates are validated against worked textbook and standards-committee examples for AISC 360-16, ACI 318-19, NDS 2018, TMS 402-16, AISI S100-16, and ASCE 7-22. Run Settings → Diagnostics → Run Self-Test to confirm your installation reproduces the reference results. ILX Calcs is an engineering aid; the engineer of record is responsible for verifying all results.

Appendix D — Accessibility

The interface supports keyboard navigation, high-contrast light and dark themes, and adjustable equation font size for high-DPI displays. The calculation flow reads top-to-bottom for screen readers, and check verdicts are conveyed with text labels, not color alone.

Appendix E — Support & Logs

Contact support at support@ilxstudio.com. Logs are at %LOCALAPPDATA%\ILX Studio\Calcs\Logs\. Include your version number (Home → About) and the relevant .ilxw file when reporting an issue.

Appendix F — Glossary

Term	Definition
Unit-aware	Every quantity carries its dimension; operations enforce dimensional consistency
Dependency graph	The network of which formulas depend on which variables, used for live recalculation
Symbolic display	Showing a formula in textbook notation before substituting numeric values
Code Ref	A cited code clause that anchors a formula to its governing standard
H1-1	AISC 360-16 interaction equation for combined axial force and flexure
P-M diagram	Axial-load versus moment interaction diagram for a concrete column
ILXReport block	A portable calculation unit that drops into a coordinated ILX Suite report

Appendix G — Revision History

Version	Date	Notes
1.0	2025	Initial release: unit-aware engine, variables/formulas/narrative, constants panel, core template set, PDF export
1.4	2026	Expanded 30+ template library across all six disciplines, versioned sheets, ILX PDF Package export, ILXReport blocks

Appendix H — Design Checklist

• Unit system set correctly for the sheet (US Customary or SI).
• Every input variable defined with a value, a unit, and a description.
• Formulas reference variables by name with no undefined or circular references.
• Material properties and section data drawn from the constants panel, not re-typed.
• Governing code clauses cited with Code Ref cells.
• Design method (LRFD/ASD) confirmed and the demand/capacity ratio shown.
• All limit-state checks pass for the controlling load combination.
• Revision added with date, engineer, and notes before issue.
• Sheet or package exported to ILX PDF and sealed by the engineer of record.