# IGES File Tools: Viewer, Area, Volume and STEP Conversion

Open IGES and IGS files, measure surfaces, and convert supported geometry to STEP. Volume exists only for valid closed solids.

IGES is a neutral CAD exchange format still used for surfaces and for legacy mechanical handoffs. This page collects the IGES tools and guides on CADProps. It does not claim that every IGES file is a solid, or that an export preserves a native feature tree.

## Open an IGES file

Use the [IGES viewer](https://www.cadprops.com/tools/iges-viewer/index.md) to inspect a self-contained `.iges` or `.igs` file. Confirm the expected faces or bodies loaded, then check one known dimension before using any calculated property. Fit-to-view only moves the camera.

## What you can measure

- Dimensions and surface area are available for readable geometry.
- Solid volume is available only when that geometry is a valid closed solid.
- Mass is that volume times a density you confirm. An open shell has no reliable mass.
- A missing volume stays unavailable. It is not written as zero.

The usual failure mode is covered in [IGES surfaces that are not solids](https://www.cadprops.com/guides/iges-surfaces-not-solid/index.md) and [STEP or IGES](https://www.cadprops.com/guides/step-vs-iges/index.md).

## Conversion

Supported directions are [IGES to STEP](https://www.cadprops.com/tools/iges-to-step/index.md) and, from a STEP file, [STEP to IGES](https://www.cadprops.com/tools/step-to-iges/index.md). Reopen the result and check units, scope and one critical face. Conversion does not recreate sketches or features.

[IGES vs Parasolid](https://www.cadprops.com/guides/iges-vs-parasolid/index.md) and [SAT vs IGES](https://www.cadprops.com/guides/sat-vs-iges/index.md) compare the neighbouring formats. [B-Rep](https://www.cadprops.com/guides/what-is-brep/index.md) is the representation behind precise face and solid properties.

## Limits

External references are not fetched. A shaded model can still be an open set of surfaces. Compare a known sample such as [box.iges](https://www.cadprops.com/samples/box.iges) when you need to separate a file problem from a viewer problem. The [format matrix](https://www.cadprops.com/supported-formats/index.md) is the full list of enabled inputs.

HTML page: https://www.cadprops.com/iges/