Calculate Weight in Fusion 360
A professional engineering tool to estimate part weight, mass properties, and material costs based on volume and density data found in Fusion 360's Physical Material library.
Fusion 360 Mass Properties Calculator
Enter the volume shown in Fusion 360 Properties window.
Please enter a valid positive number.
Cubic Millimeters (mm³)
Cubic Centimeters (cm³)
Cubic Meters (m³)
Cubic Inches (in³)
Cubic Feet (ft³)
Select the unit currently set in your Fusion 360 Document Settings.
Aluminum 6061 (2.70 g/cm³)
Steel, Mild (7.85 g/cm³)
Stainless Steel 304 (8.00 g/cm³)
Titanium (4.51 g/cm³)
Copper (8.96 g/cm³)
ABS Plastic (1.04 g/cm³)
PLA Plastic (1.24 g/cm³)
Wood, Oak (0.70 g/cm³)
Gold (19.32 g/cm³)
Custom Density…
Select a standard material or choose Custom.
Enter density in g/cm³. Water is approx 1.0.
Optional: Enter raw material cost to estimate total part price.
Calculated Weight
0.00 kg
0.00 lbs
Weight (Grams)
0 g
Weight (Ounces)
0 oz
Est. Material Cost
$0.00
Mass (M) = Volume (V) × Density (ρ)
Current Selection
Comparative Materials
Figure 1: Weight comparison of your volume across common materials.
| Property | Value | Unit |
|---|
What is "Calculate Weight in Fusion 360"?
When engineers and designers ask how to calculate weight in Fusion 360, they are typically referring to the process of using the software's "Mass Properties" tool to determine the physical mass of a 3D component or assembly. This calculation is vital for verifying if a design meets engineering constraints, estimating shipping costs, or determining raw material requirements.
Fusion 360 calculates weight automatically if a Physical Material is applied to the body. However, misconceptions often arise when users apply an "Appearance" (which only changes color/texture) instead of a "Physical Material" (which applies density data). Without the correct density, the software defaults to steel or fails to calculate weight accurately.
This tool is designed for mechanical engineers, product designers, and hobbyists who need to quickly verify Fusion 360 data or estimate weights for materials not currently loaded in their software library.
The Formula for Fusion 360 Weight Calculation
While Fusion 360 handles the complex geometry integration to find volume, the underlying math to calculate weight in Fusion 360 is based on fundamental physics. The software computes the total volume of the closed mesh or solid body and multiplies it by the density of the assigned material.
$$ Mass (m) = Volume (V) \times Density (\rho) $$
For financial and logistical planning, understanding the units is critical. Fusion 360 often defaults to CGS (Centimeters-Grams-Seconds) or MMGS (Millimeters-Grams-Seconds) systems.
Variables Table
| Variable | Meaning | Common Units (Fusion 360) | Typical Range |
|---|---|---|---|
| V | Volume | mm³, cm³, m³ | 0.1 to 1,000,000+ |
| ρ (Rho) | Density | g/cm³, kg/m³ | 1.0 (Water) to 19.3 (Gold) |
| m | Mass/Weight | g, kg, lb | Variable |
Practical Examples of Weight Calculation
Example 1: The Aluminum Enclosure
An engineer designs a small electronics enclosure. The volume analysis in Fusion 360 shows the part has a volume of 150,000 mm³. The material selected is Aluminum 6061.
- Volume: 150,000 mm³ = 150 cm³
- Density of Aluminum 6061: ~2.70 g/cm³
- Calculation: 150 cm³ × 2.70 g/cm³ = 405 grams
- Financial Impact: If aluminum costs $4.50/kg, the raw material cost is approximately $1.82 per unit.
Example 2: Steel Structural Bracket
A heavy-duty bracket for a construction project has a volume of 50 cubic inches. The material is Mild Steel.
- Volume: 50 in³ ≈ 819.35 cm³
- Density of Steel: ~7.85 g/cm³
- Calculation: 819.35 cm³ × 7.85 g/cm³ = 6,431.9 grams (6.43 kg)
- Result: The bracket weighs approximately 14.18 lbs.
How to Use This Fusion 360 Weight Calculator
Follow these steps to replicate or verify the mass properties found in your CAD software:
- Get Volume Data: In Fusion 360, right-click your component in the browser tree and select "Properties". Note the Volume value and unit.
- Input Volume: Enter this number into the "Volume Value" field above.
- Select Unit: Ensure the dropdown matches the unit shown in Fusion (usually mm³ or cm³).
- Choose Material: Select the material you intend to use. If your specific alloy isn't listed, select "Custom" and input the density from the material datasheet.
- Analyze Results: View the calculated weight in kilograms and pounds to determine shipping requirements or structural loads.
Key Factors That Affect Weight Results
When you calculate weight in Fusion 360, several factors can lead to discrepancies between the digital model and the physical part:
- Material Density Accuracy: Generic material libraries often use average densities. Real-world alloys vary slightly (e.g., Steel can range from 7.75 to 8.05 g/cm³).
- Manufacturing Tolerances: A machined part may be slightly larger or smaller than the CAD nominal dimensions, affecting actual volume and weight.
- Infill Percentage (3D Printing): Fusion 360 calculates weight as a solid object (100% infill). If you 3D print with 20% infill, the actual part will weigh significantly less than the calculated value.
- Surface Coatings: Paint, powder coating, or plating adds mass that is rarely modeled in the CAD geometry volume.
- Hardware and Fasteners: Assemblies often exclude small screws, glue, or grease in the volume calculation, leading to an underestimation of total system weight.
- Mesh Resolution: In complex organic shapes, the mesh approximation used for volume calculation might deviate slightly from the perfect mathematical surface.
Frequently Asked Questions (FAQ)
1. Why does Fusion 360 say my density is 1.00 g/cm³?
This usually happens when no physical material has been assigned, or the default material is set to "Water" or a generic placeholder. Check your Physical Material settings.
2. Does changing the Appearance affect the weight calculation?
No. Changing "Appearance" only affects the visual rendering (color/texture). You must change the "Physical Material" to update the mass properties.
3. How do I calculate weight for 3D printed parts?
Fusion 360 calculates for solid parts. For 3D printing, take the result and multiply by your infill percentage (e.g., Result × 0.20 for 20% infill), plus a margin for walls and top/bottom layers.
4. Can I add custom materials to Fusion 360?
Yes, you can manage the Physical Material library and add custom materials with specific density values to get accurate weight calculations.
5. Is the volume in Fusion 360 always accurate?
Generally, yes. However, if you have intersecting bodies or open surfaces (non-watertight geometry), the volume calculation may fail or be inaccurate.
6. What is the difference between Mass and Weight in CAD?
CAD software calculates Mass (kg). Weight is the force of gravity on that mass (Newtons or lbs). However, in common industry terms, "weight" is often used interchangeably with mass (kg/lbs).
7. How can I reduce the weight of my design?
You can use the "Shell" command to hollow out parts, choose a lower-density material (like switching from Steel to Aluminum), or use Generative Design to optimize geometry.
8. Does this calculator account for manufacturing costs?
This calculator provides a raw material cost estimate. It does not account for machining time, overhead, labor, or machine wear.
Related Tools and Internal Resources
Enhance your engineering workflow with these related resources:
- Material Density Converter – Convert between imperial and metric density units.
- CNC Machining Cost Estimator – Estimate the labor and machine time for your designs.
- 3D Printing Filament Calculator – Calculate spool usage based on slicer data.
- Metal Weight Charts – Reference tables for standard steel and aluminum profiles.
- Fusion 360 Optimization Guide – Learn how to use simulation to reduce part mass.
- Sheet Metal Gauge Table – Standard thicknesses for sheet metal fabrication.