The Fillet Volume Calculator helps engineers, designers, and machinists quickly find the extra or reduced material volume caused by adding fillets to sharp corners or edges in mechanical parts. Knowing the fillet volume is useful for estimating material cost, weight, and machining time. It also ensures precise material balance in castings, welds, and molded parts. This calculator is part of the Mechanical Design and Manufacturing Calculator category and is used in CAD design, metalworking, and quality control.
formula of Fillet Volume Calculator
- For a simple fillet along an internal right-angle corner (quarter of a cylinder):
Fillet Volume = (1/4) × π × r² × L
Where:
r is the fillet radius
L is the length along the corner or edge
π is about 3.14159
- For a fillet along a straight edge (like on the side of a plate):
Fillet Volume = (1/4) × π × r² × Edge Length
This is the same form and applies when the fillet follows a straight path.
- For a fillet around a hole or pipe edge (a full internal fillet ring, torus-like):
Fillet Volume ≈ 2 × π² × r² × R
Where:
r is the fillet radius
R is the mean radius of the hole or pipe wall where the fillet goes
These formulas give a reliable estimate for practical manufacturing planning.
Common Fillet Volumes Reference Table
This table shows typical fillet volumes for standard cases to help you plan without recalculating every time.
| Fillet Radius (mm) | Edge Length (mm) | Approx. Volume (mm³) |
|---|---|---|
| 2 | 100 | 314 |
| 3 | 100 | 707 |
| 5 | 100 | 1,963 |
| 5 | Hole R = 20 | 19,739 |
| 10 | Hole R = 20 | 78,956 |
These values help check rough material additions or removals during design reviews.
Example of Fillet Volume Calculator
Let’s work through an example.
You add a fillet with:
r = 5 mm
L = 200 mm (along a plate edge)
- Use the straight edge formula:
Fillet Volume = (1/4) × π × r² × L - Calculate:
(1/4) × π × 5² × 200
= 0.25 × 3.14159 × 25 × 200
= 0.25 × 3.14159 × 5,000
= 0.25 × 15,707.95
= 3,926.99 mm³
So, the fillet will add about 3,927 cubic millimeters of material along this edge.
Most Common FAQs
Knowing fillet volume helps estimate total part weight, raw material cost, and affects how much extra material is needed for machining or casting.
Not always, but fillets reduce stress at sharp corners, improve part strength, and help with smoother fluid or stress flow. They also make machining easier.
Yes, the same principle applies for external rounded edges. The volume shows how much material forms the rounded feature compared to a sharp corner.