Convert 3DM
to IGES.

Updated 2026-10-19

To convert 3DM (.3dm) to IGES (.iges / .igs), drop the file below and download the result, in the browser with nothing installed. NURBS bodies in the Rhino file are translated to IGES exactly.

2 solid-geometry conversions a day with no account. No card, no install.

No account needed
Drop a 3DM file.3dm · up to 200 MB

On our servers. No account: deleted within 24 hours. Signed in: kept until you delete them. Never shared or used for training.

ResultExact where NURBS

Trimmed NURBS breps and lightweight extrusions become true surfaces in the IGES output, with nothing tessellated, in millimetres whatever the model's unit. Mesh and SubD objects beside them come too, rebuilt as true surfaces where they fit and facets where they do not. Hidden objects are left out, and the converter says how many.

A 3DM that is all mesh has its surfaces recovered from the triangles where they fit and facets where they do not, and the conversion says which of the two it gave.

HowThree steps
  1. Drop your .3dm file above — up to 200 MB without an account.
  2. IGES is already selected as the output.
  3. Download the .iges. Without an account, files are deleted within 24 hours; signed in, they are kept until you delete them.
FormatsWhat you are holding

Rhinoceros 3D model file (.3dm)

A 3DM file is a Rhino model. Rhino is a NURBS modeller, dominant in industrial design, jewellery, marine and architecture. A 3DM can mix exact breps, surfaces, meshes and curves on layers; polysurfaces and extrusions convert exactly, and mesh objects come along: as meshes in a mesh format, rebuilt as true surfaces in a solid one.

A designer works in Rhino and engineering or manufacturing needs the shape in a format their system reads.

IGES file (Initial Graphics Exchange Specification) (.iges / .igs)

IGES predates STEP and is still requested by older CAM systems and mould and die workflows. It stores exact geometry, but many IGES files are loose trimmed surfaces that never close into a watertight solid. Unless someone asks for IGES by name, STEP is the better choice.

A CAM programmer, toolmaker or legacy system asked for IGES, or you were handed one and need something current.

Questions8 answered
Is the 3DM to IGES converter free?
Yes. 2 solid-geometry conversions a day with no account, of 5 in total. A free account converts 4 solid files a day and adds 25 credits. No card.
Do I need Rhino installed?
No. The 3DM file is read in the browser with nothing installed and no Rhino licence.
Does anything change in the geometry?
NURBS bodies in the Rhino file are translated to IGES exactly. Trimmed NURBS breps and lightweight extrusions become true surfaces in the IGES output, with nothing tessellated, in millimetres whatever the model's unit. Mesh and SubD objects beside them come too, rebuilt as true surfaces where they fit and facets where they do not. Hidden objects are left out, and the converter says how many. A 3DM that is all mesh has its surfaces recovered from the triangles where they fit and facets where they do not, and the conversion says which of the two it gave.
Will the IGES file open in Fusion 360, Inventor or Onshape?
Yes. IGES is read directly by Fusion 360, Inventor, Onshape, SOLIDWORKS, Creo, NX and FreeCAD. It arrives as a solid body you can measure, mate and cut.
Should I use IGES or STEP?
STEP, unless a CAM system or toolmaker asks for IGES by name. Both carry exact geometry, but STEP is the current ISO standard and closes into a solid more reliably.
How big a file can I convert?
To a mesh format like STL: 300 MB with a free account, 200 MB without one. To STEP, Parasolid or SLDPRT: 140 MB, because rebuilding a solid takes about twice the memory of writing a mesh. Maker and Studio convert up to 830 MB and 380 MB — a large conversion on a paid plan gets the server to itself.
Is it safe to upload my 3DM file?
Files travel encrypted and are processed by machine on our own servers — no third parties, no ads or trackers, no AI training.
Is my 3DM file deleted after converting?
Without an account, the upload and the result are deleted within 24 hours. With an account, both stay in your files until you delete them; deleted files leave our servers within 24 hours.
Beyond convertingSame file, four workspaces

Keep the part open: fill it with a lattice, check it with FEA, texture a surface, or slice it into cut-ready sheets. These workspaces are in early access — create an account, then apply from inside the app.

Create free account See pricing

AlsoOther ways in
MoreRelated conversions

Going the other way? Convert IGES to 3DM.

Rhinoceros® and Rhino® are registered trademarks of Robert McNeel & Associates. MeshWeave is an independent tool and is not affiliated with, endorsed by, or sponsored by Robert McNeel & Associates.