# CAD Weight Calculator: STEP Volume & Material Density

Estimate mass from valid STEP solid volume and your chosen material density. Inspect the model, verify units and download a property CSV without an account.

Calculate part mass from a valid volume and an explicit density. This is the physical mass of the part, not the size of a STEP, SolidWorks or NX file on disk.

## Use volume and density in compatible units

For a 24,000 mm³ block and a density of 2.70 g/cm³, the calculated mass is 64.8 g. Divide the volume by 1,000 to convert mm³ to cm³ before multiplying by density. This arithmetic example does not certify the material of your own model.

## Material and scope are inputs

Do not assume a density from appearance. Mixed-material assemblies need component-level inputs and instance counts. Imported mass metadata should be shown separately from a newly computed value.

## Keep invalid results out of totals

An open shell or incomplete assembly cannot be quietly treated as a fully resolved solid. Show an unavailable status and the reason. Batch reports should retain failed rows rather than replacing them with zeros.

<!-- verified-tool-workflow -->

**Input formats:** STEP / STP

[Open this tool](https://www.cadprops.com/workspace/index.md)

General steps for uploading, viewing, sectioning, measuring, converting and exporting are explained once in [How it works](https://www.cadprops.com/how-it-works/index.md). This page covers what is specific to this file type.

## Real CADProps screenshots

The screenshots show the English interface. Captions and instructions describe the same operations.

<figure class="workflow-evidence"><img src="/assets/evidence/tools-2026-10-01/step-viewer-1440.webp" alt="Properties — block.step · 40 × 30 × 20 mm · 24,000 mm³ · 5,200 mm²" width="1440" height="1121" loading="lazy"><figcaption>Properties — block.step · 40 × 30 × 20 mm · 24,000 mm³ · 5,200 mm²</figcaption></figure>

[Sample source and verification](https://www.cadprops.com/samples/block.step)

<figure class="workflow-evidence"><img src="/assets/evidence/tools-2026-10-01/properties-density-1440.webp" alt="Material &amp; density — block.step · 7.85 g/cm³ → 188.4 g" width="1440" height="1121" loading="lazy"><figcaption>Material &amp; density — block.step · 7.85 g/cm³ → 188.4 g</figcaption></figure>

<figure class="workflow-evidence"><img src="/assets/evidence/tools-2026-10-01/properties-imperial-1440.webp" alt="Display units — block.step" width="1440" height="1121" loading="lazy"><figcaption>Display units — block.step</figcaption></figure>

<figure class="workflow-evidence"><img src="/assets/evidence/tools-2026-10-01/properties-export-1440.webp" alt="Export CSV · mm / g — block.step" width="1440" height="3112" loading="lazy"><figcaption>Export CSV · mm / g — block.step</figcaption></figure>

[Export CSV · mm / g](https://www.cadprops.com/assets/evidence/tools-2026-10-01/properties.csv)

## When a result needs another check

Viewing can start without an account. Conversion, account storage and share creation require signing in. Temporary files expire after the displayed retention period. Read the privacy statement for server processing and deletion, and the accuracy notes before using numerical results. Do not assume that hiding a part, clipping it or exploding an assembly changes the exported source geometry.

[When a result needs another check](https://www.cadprops.com/accuracy/index.md) · [Input formats](https://www.cadprops.com/supported-formats/index.md)

## Continue with a related task

- [CAD Volume Calculator: Measure STEP Solid Volume](https://www.cadprops.com/tools/cad-volume-calculator/index.md)
- [STEP File Dimensions Online: Measure X, Y, Z & Distances](https://www.cadprops.com/tools/cad-dimensions/index.md)
- [Batch STEP Properties: Export CAD Measurements to CSV](https://www.cadprops.com/tools/batch-cad-processing/index.md)

## Capabilities and limits

- Estimate mass from valid STEP solid volume and your chosen material density. Inspect the model, verify units and download a property CSV without an account.
- Estimated mass is volume multiplied by user-confirmed material density; it is not a physical weighing result.
- Files are uploaded for server processing; support depends on format, version and geometry.
- Viewing and measuring do not require an account. Sign in to convert, save files across devices or create share links.

## Questions about this task

### How do I choose material density when calculating CAD model weight?

You select or enter density. Presets are generic assumptions, not a material certificate from the file.

### Why is the calculated weight missing for my CAD model?

Mass requires a usable closed-volume result and positive density. Open or invalid geometry has no reliable mass result.

### Is my CAD file uploaded to a server to calculate weight?

Selecting a file starts temporary server processing. For guests, access to the workspace copy is limited to the browser session; it can be deleted early and expires after the displayed period. Signed-in files are saved to the account library when space is available; otherwise they remain temporary.

HTML page: https://www.cadprops.com/tools/cad-weight-calculator/