The free IEC 62305-2 tools, and which edition each one computes

1. Check the edition before comparing access

DEHN distinguishes its Ed. 2 desktop Toolbox from the Ed. 3 DEHNrisk web application. ECalPro presents a selector for both 2010 and 2024. Voltbench implements Ed. 3.0:2024. Match the selected method to your project specification and national adoption; see our edition guide.

2. Published access and document options

3. Compare the work you actually need

A subscription can cost less than buying individual study entitlements here. There is no universal crossover: the published prices use different currencies, and tax, exchange rates, licence terms and the documents you need affect the comparison. Compare annual costs in one currency for the same scope.

For a single risk assessment, check the risk inputs, trace and export. For a full building project, also check geometry editing, protection layouts, service and equipment schedules, how the studies share their basis, and how revisions are issued. A report entitlement does not include an engineer's professional review.

Voltbench's one-building walkthrough shows its multi-part model, corner editing, three studies and document controls. The sample dossier shows the combined output before you buy.

4. Three useful checks, including on our own tool

These spot checks help you inspect an assessment; they do not establish full conformity or replace validation. Check the selected edition and the calculation working as well as the summary screen.

Check 1 — ask it for R4

The current edition removes the old R4 economic-loss assessment. If a tool offers it, check whether you have selected an older edition or a separate economic analysis. Its presence elsewhere in a multi-edition product does not establish which method your current assessment uses.

Check 2 — make it compute a collection area you already know

The collection area of an isolated structure extends outward from the walls by three times the building height, rounded at the corners — not by the height itself. Getting this wrong is a single-character error with a large consequence, and it is invisible unless you check it, because the number looks plausible either way.

So give the tool a rectangular building on flat open ground with nothing taller nearby: 200 m × 200 m × 35 m. The collection area should come out at roughly 158 600 m². A tool that extends by the height instead of three times the height returns about 71 800 m² — near enough 45% of the correct figure, and every event rate downstream is scaled by that same factor. Our own figure for this building is 158 636 m²; we print the collection area on every report precisely so this check is available to you.

Check 3 — see whether the verdict is per zone

Review the result for each risk zone and identify which zone drives the decision. A structure-wide summary alone is insufficient to inspect this. Ask for the zone calculation before drawing conclusions about the underlying engine.

If any tool fails these, that is worth knowing before it is under your name on a document. If you run them here and something looks wrong, we would rather hear it from you than find out later — the validation page sets out what our engine was reconciled against, including what did not match first time.