Many people need a quick, reliable way to convert DGN to DWG for free — whether to open a client file in AutoCAD, to preserve drawing data, or to integrate work between Bentley and Autodesk ecosystems. Below you’ll find a clear, beginner-friendly guide with several methods (free and paid), step‑by‑step instructions, common errors and fixes, and practical tips so you can pick the best workflow for your files.
Why convert DGN to DWG?
- DGN is Bentley Systems’ native CAD format (MicroStation).
- DWG is Autodesk’s proprietary format used by AutoCAD and many other CAD tools.
- Converting is necessary when a team or client uses different CAD platforms, or when tools in the Autodesk ecosystem must read/edit a DGN file.
- Some conversions need to preserve layers/levels, text, blocks/cells, coordinates, and drawing scale.
Quick answer (short & simple)
If you want a free solution: use GDAL/OGR (ogr2ogr) or QGIS to convert the DGN to DXF, then convert that DXF to DWG using the free ODA File Converter (Open Design Alliance) or open the DXF in AutoCAD and save as DWG. For the most reliable results (native mapping of elements, cells, references), use MicroStation or a MicroStation trial to export directly to DWG.
Complete step-by-step tutorials
Method A — Best quality (recommended if available): MicroStation (native)
- Open the .dgn in MicroStation (or a MicroStation trial).
- Use File > Save As or File > Export and choose DWG as output format (select the DWG version you need, e.g., AutoCAD 2018).
- In export options, map levels to layers, set units and coordinate system, and choose options for text/font mapping and cell/block conversion.
- Save and open the DWG in AutoCAD to verify layers, text, and geometry.
Notes:
- This preserves the most native features (cells, references, tags).
- MicroStation is paid but offers a trial that can be used for occasional conversions.
Method B — Free, reliable workflow (GDAL/OGR → DXF → DWG)
Overview: Convert DGN to DXF using GDAL/OGR (or QGIS), then convert DXF to DWG with ODA File Converter or AutoCAD.
Step 1 — Convert .dgn to .dxf with ogr2ogr (command line)
- Install GDAL (comes with ogr2ogr).
- Run:
ogr2ogr -f “DXF” output.dxf input.dgn - Optional flags:
- -skipfailures (skip unreadable features)
- -t_srs EPSG:xxxx (to reproject)
Step 1 (GUI alternative) — QGIS
- Open QGIS (free).
- Layer > Add Layer > Add Vector Layer > open your .dgn file.
- Right-click the layer > Export > Save Features As… > Format: DXF > select CRS/units and save.
Step 2 — Convert the DXF to DWG
Option 1 — ODA File Converter (free)
- Download and install ODA File Converter from the Open Design Alliance.
- Select input folder (where output.dxf is) and output folder, choose target DWG version, and run conversion.
Option 2 — AutoCAD
- Open output.dxf in AutoCAD.
- Use File > Save As > choose DWG (version).
- Inspect and fix layers/text as needed.
Notes:
- This route is fully free (QGIS + GDAL + ODA Converter).
- Use DXF as the interchange layer because DWG writers are restrictive; ODA Converter reliably writes DWG from DXF input.
Method C — Quick web-based converters (fast but limited)
- Use online services (e.g., Zamzar, AnyConv) that support DGN → DWG.
- Upload your .dgn, choose DWG, and download converted file.
Cautions:
- Privacy: do not upload confidential or large files.
- Limits: file size restrictions and potential loss of advanced elements (cells, tags).
- Quality: may not preserve layers/blocks exactly.
Method D — AutoCAD Map 3D / Civil 3D (if you have Autodesk subscription)
- Use MAPIMPORT (or Import command in Map 3D) to load the DGN.
- Map levels to layers and choose units/coordinate transforms.
- Save the opened drawing as a DWG.
Notes:
- These Autodesk products have better DGN interoperability than base AutoCAD.
- Good when coordinate system and attribute mapping are critical.
Common problems and fixes
Problem: Elements missing or invisible after conversion
- Fix: Check that layers/levels weren’t filtered out. Ensure layer visibility is on in the target application. Try converting with “all levels” or “export visible only” toggles adjusted.
Problem: Blocks/cells converted to exploded geometry or lost attributes
- Fix: Use MicroStation export options to map cells to blocks. If using ogr2ogr, accept that some complex cell behavior may be flattened — you may need MicroStation for full fidelity.
Problem: Text appears as single lines or wrong font
- Fix: Ensure font mapping is set during export. If fonts aren’t available, AutoCAD substitutes — install the same TrueType fonts or map fonts manually.
Problem: Units or scale wrong
- Fix: Confirm and set the correct units during export/import. In ogr2ogr/QGIS, set the layer CRS/units and use -t_srs if reprojection is needed.
Problem: Coordinates shifted or rotated
- Fix: Check coordinate reference systems (CRS). If DGN uses a site or project coordinate offset, apply the same offset or reproject during conversion.
Problem: References (XREFs in DGN) not converted
- Fix: Resolve references in the source (attach/merge) or export with options that include references; otherwise convert each referenced DGN separately and re-attach in DWG.
Problem: Large file or long conversion times
- Fix: Break into smaller files (by model or area), convert batch-wise, or use a local tool (MicroStation) to speed processing.
Tips for best results
- Always make a backup of the original DGN before conversion.
- If fidelity matters, prefer MicroStation (native) or request the sender to export DWG themselves.
- Use DXF as an intermediate if direct DGN→DWG tools aren’t available.
- Test with a small sample file first to refine export settings (fonts, units, levels).
- When using online converters, remove sensitive metadata and be mindful of confidentiality.
- Keep track of DWG version compatibility (AutoCAD 2018, 2013, 2007, etc.). Use ODA File Converter to change DWG versions if needed.
- Document any layer/level mapping so collaborators know how data moved across platforms.
FAQ
Can I convert DGN to DWG for free without installing any software?
Yes — you can use online converters, but they have file size limits and privacy concerns. A better no-install free route is to use QGIS Portable (runs without full install) to export to DXF, then the ODA File Converter (small install) to produce DWG.
Will converting DGN to DWG change coordinates or georeferencing?
It can. Always verify and, if needed, reproject or apply site offsets during export. Use tools that let you specify CRS and coordinate transforms.
Does DXF to DWG conversion preserve layers and blocks?
Generally yes, if the DXF contains layer and block information and you use a reliable converter (AutoCAD or ODA File Converter). Some complex attributes or custom DGN elements may still be lost or flattened.
My converted DWG has exploded text or missing fonts — what can I do?
Install the same fonts used in the DGN on your system, or map fonts during export. If text became polylines, try converting text back from geometry is difficult; better to re-export preserving text entities.
Are there command-line tools for batch converting many DGN files at once?
Yes. Use ogr2ogr in scripts to produce DXF for multiple files, then use ODA File Converter in batch mode. MicroStation can also be scripted with MDL/Cell or batch utilities if you have access.
Which method gives the most faithful conversion?
MicroStation export to DWG is typically the most faithful because it understands DGN native constructs (cells, references, tags). For free solutions, ogr2ogr/QGIS + ODA Converter is the most reliable alternative.
Is metadata (title, author, tags) preserved?
Not always. Metadata might not survive the conversion, especially when going through DXF or online converters. Export and check metadata fields separately where possible.
Can I automate DGN → DWG conversion on a server?
Yes, with caution. You can script GDAL/OGR and ODA File Converter for batch server-side processing, but watch licensing for commercial automation and handle file privacy/security properly.