DIALux EVO vs. AGi32: Which Software Produces Better Photometric Plans?

AGi32 and DIALux EVO are the two dominant photometric calculation engines used by lighting professionals in North America. AGi32, developed by Lighting Analysts (now part of Revalize), is commercial software recognized as the industry standard for exterior site lighting calculations and permit-ready photometric plans in the US market. DIALux EVO, developed by DIAL GmbH in Germany, is free to use, excels at interior lighting design and photorealistic 3D visualization, and is the most widely used lighting software globally with support from over 190 luminaire manufacturers.

The question isn't really "which is better" — it's which one fits your project, your workflow, and whether you're producing a plan for a permit reviewer in Houston or a design presentation for a client in Munich.

The comparison

Factor	AGi32	DIALux EVO
Price	~$133/month single-user subscription (~$1,600/year)	Free
Developer	Lighting Analysts / Revalize	DIAL GmbH (Germany)
OS	Windows	Windows
Primary strength	Exterior site lighting, permit-ready calculations	Interior design, 3D visualization, rendering
Calculation engine	Direct-component + full radiosity; ±2% illuminance accuracy	Radiosity-based; accurate with strong visual output
Exterior site lighting	Industry standard for US commercial site plans	Capable, but less common for US exterior permitting
Interior lighting	Capable, not the primary use case	Excellent — preferred for interior design projects
IES file support	Native .ies; Instabase photometric database	Native .ies and .ldt (EULUMDAT)
Report output	Highly customizable, permit-oriented templates	Polished visual reports and renderings
3D rendering	Radiosity-based rendering with ray tracing	Strong photorealistic rendering
CAD integration	DWG/DXF import; exports to AutoCAD	DWG/DXF import; SketchUp integration
Learning curve	Steep — designed for lighting specialists	Moderate — more accessible interface
US market share	Dominant for exterior commercial plans	Growing, especially for interior and mixed-use

A few of these warrant context.

Where AGi32 earns its reputation

Picture a 200-space retail parking lot in a municipality that requires a point-by-point calculation grid at 10-foot spacing, IES RP-8 compliance documentation, light trespass calculations at all four property boundaries, and a uniformity ratio analysis for each calculation zone. The plan reviewer has seen hundreds of photometric submittals and expects a specific report format.

This is AGi32's home territory. Its direct-component calculation engine is built for exactly this workflow — fast, precise exterior illuminance calculations with accurate shadowing from buildings, canopies, and grade changes. The output is a report format that US plan reviewers recognize and trust, with customizable templates that map directly to jurisdictional submittal requirements.

AGi32's calculation accuracy is verified at ±2% for illuminance and ±3% for luminance — numbers that matter when the difference between 0.4 fc and 0.5 fc at the property boundary determines whether the plan passes or fails a dark sky ordinance.

The software handles complex exterior scenarios that simpler tools struggle with: multiple overlapping calculation zones, roadway luminance calculations (for DOT projects), sports lighting with high-mast aiming angles, and multi-level parking structure transitions. If the project involves exterior lighting and a US building permit, AGi32 is the default choice for most professional photometric designers.

Where DIALux EVO shines

Now imagine a different project: a 40,000 sf open-plan office where the architect wants to see photorealistic renderings of the lighting design, the client needs to visualize how the space feels before committing to a fixture package, and the design must demonstrate daylight integration through a curtain wall facade.

DIALux EVO is built for this. Its 3D modeling environment creates immersive visual presentations that communicate design intent far more effectively than a spreadsheet of foot-candle values. Interior designers, architects, and lighting designers use it to iterate through options visually — swapping fixture families, adjusting color temperatures, and showing the client exactly what a 3500K recessed linear looks like versus a 4000K pendant.

The manufacturer integration is a key advantage. Over 190 luminaire manufacturers publish DIALux-compatible product catalogs (plugins), which means the designer can search for, place, and calculate with real fixture data directly within the software. Major brands — Signify (Philips), ERCO, Hubbell, Cooper Lighting Solutions, iGuzzini, Schréder — all maintain current DIALux catalogs.

And the price is hard to argue with: DIALux EVO is free. DIAL funds the software through manufacturer partnerships rather than user licenses. For a small firm, a freelance designer, or an architect who does occasional lighting work, this removes a significant cost barrier.

What most comparisons get wrong

The internet is full of "DIALux vs. AGi32" articles that try to pick a winner. Most miss the point.

Many US lighting firms use both. Chris Bailey of Hubbell Lighting has described the practical split: AGi32 for outdoor calculations, their DIALux-based tool for interior calculations and 3D renderings. This isn't indecision — it's recognizing that the two tools serve different parts of the same project.

A commercial development with a parking lot, building perimeter lighting, and an interior office space might use AGi32 for the exterior photometric plan (the permit document) and DIALux EVO for the interior design (the presentation document). The exterior plan goes to the plan reviewer. The interior visualization goes to the client and the architect.

The only scenario where they're true competitors is a mid-complexity interior project where the designer needs both calculations and visual output. For that specific use case, DIALux EVO's combination of free access, strong rendering, and manufacturer catalog integration makes it the practical choice for most firms.

Can you produce a permit-ready photometric plan with each?

Technically, yes. Both AGi32 and DIALux EVO calculate illuminance from IES file data and produce point-by-point grids. Both can generate a report showing foot-candle values, uniformity ratios, and fixture schedules.

In practice, the distinction matters for US exterior projects. AGi32's report formatting is what US plan reviewers expect and recognize. A DIALux EVO plan contains the same underlying data, but the output format may require reformatting to match jurisdictional expectations — different calculation grid presentation, different summary statistics layout, different compliance documentation structure.

For interior-only projects, DIALux output is widely accepted. For international projects, DIALux is often preferred. For US exterior site plans submitted for building permits — parking lots, gas stations, car dealerships, warehouse perimeters, commercial campuses — AGi32 output is the path of least resistance through plan review.

The "should I do it myself?" reality check

If you're reading this article because you're considering producing your own photometric plan, here's the honest assessment.

The software is the easy part. DIALux EVO is free. AGi32 offers a 14-day trial and subscriptions start around $133/month. You can download either one today and start learning.

The expertise is the hard part. Knowing which IES standard applies to your project, what uniformity ratio your plan reviewer expects, what Light Loss Factor to use for outdoor LED fixtures in your climate zone, how to document compliance for a Title 24 jurisdiction or a dark sky ordinance, what calculation grid spacing satisfies your specific plan reviewer — none of this comes with the software license.

A contractor who buys AGi32 but doesn't understand IES RP-8 or their municipality's outdoor lighting code will produce a plan that calculates correctly but fails review for documentation deficiencies. The software computes the numbers. The designer knows which numbers matter and how to present them.

This is where a professional photometric plan earns its fee — not because the software is expensive, but because the knowledge behind it takes years to develop.

Frequently asked questions

Is DIALux EVO really free?

Yes. DIAL GmbH funds DIALux through partnerships with luminaire manufacturers who pay to have their product catalogs integrated into the software. The user pays nothing — no license fee, no subscription, no feature limitations. You download it from dialux.com.

Which software do plan reviewers prefer?

Plan reviewers don't typically specify software. They evaluate the quality and completeness of the deliverable — the calculation grid, uniformity analysis, fixture schedule, and compliance documentation. That said, AGi32 output formats are what most US plan reviewers have seen for decades, so the report layout is immediately familiar to them.

Can I use DIALux EVO for an exterior parking lot plan?

Yes. DIALux EVO can model exterior sites, place pole-mounted fixtures, and calculate point-by-point illuminance grids. The calculations will be accurate. The question is whether the output format matches what your plan reviewer expects for the permit submittal. For straightforward projects with standard submittal requirements, it can work. For complex or code-heavy jurisdictions, you may need to reformat the output.

How much does AGi32 cost?

AGi32 uses a subscription model. A single-user license is approximately $133/month. Multi-user licenses are available at higher rates. Lighting Analysts also offers free educational licenses. Pricing may vary — check lightinganalysts.com for current rates.

Do I need photometric software to get a photometric plan?

No. You can commission a photometric plan from a professional design service without owning or operating any software yourself. You provide the site plan and project details; the designer handles the modeling, calculations, and compliance documentation using their licensed software.