BIZOMAT Tools · Manufacturing
Rack and Batch Fit
How many parts fit on a rack, jig or tray?
Calculates how many rectangular parts fit on a rack or panel with a set clearance, in both orientations.
Open the calculatorRuns in your browser. No account needed.
How this tool works
Inputs, units and where to find them
| Input | Unit | Typical source |
|---|---|---|
| Usable rack width | mm | Usable rack width after edge clearance |
| Usable rack height | mm | Usable rack height after edge clearance |
| Part width | mm | Part envelope width as hung |
| Part height | mm | Part envelope height as hung |
| Clearance between parts | mm | Minimum clearance between parts required by the process |
What each input means
Open an input to see what it is, its units, the worked example and the common mistakes, with a small diagram.
What this means: Usable rack width
- What it is
- The horizontal space on the rack, jig or carrier that parts can actually occupy, after the clearance needed at each edge has been taken off.
- Units and format
- Enter a number in mm: millimetres. The form accepts 1 mm or more.
- Example
- The form opens with 1200 mm as a worked example. It is an illustration, not a recommended value: replace it with your own figure.
- Effect on the result
- More width fits more columns of parts.
- Get it right
- Measure inside any edge clearance the process needs; the tool adds no clearance at the rack edges.
What this means: Usable rack height
- What it is
- The vertical space on the rack, jig or carrier available for parts, after top and bottom edge clearance.
- Units and format
- Enter a number in mm: millimetres. The form accepts 1 mm or more.
- Example
- The form opens with 1000 mm as a worked example. It is an illustration, not a recommended value: replace it with your own figure.
- Effect on the result
- More height fits more rows of parts.
- Get it right
- Allow for hooks and hangers above the top row before measuring.
What this means: Part width
- What it is
- The width of the rectangle that fully encloses one part as it hangs or sits on the rack, including any hook or protrusion.
- Units and format
- Enter a number in mm: millimetres. The form accepts 1 mm or more.
- Example
- The form opens with 100 mm as a worked example. It is an illustration, not a recommended value: replace it with your own figure.
- Effect on the result
- A wider part fits fewer columns.
- Get it right
- Use the overall envelope, not a nominal size; the tool also tries the part rotated 90° and keeps the better result.
What this means: Part height
- What it is
- The height of the rectangle that fully encloses one part as it hangs or sits on the rack, including any hook or protrusion.
- Units and format
- Enter a number in mm: millimetres. The form accepts 1 mm or more.
- Example
- The form opens with 150 mm as a worked example. It is an illustration, not a recommended value: replace it with your own figure.
- Effect on the result
- A taller part fits fewer rows.
- Get it right
- Include the hanging point or fixture in the height if it adds to the envelope.
What this means: Clearance between parts
- What it is
- The minimum space the process needs between neighbouring parts, for example for coating access, drainage, airflow or to stop parts touching.
- Units and format
- Enter a number in mm: millimetres. The form accepts 0 mm or more.
- Example
- The form opens with 20 mm as a worked example. It is an illustration, not a recommended value: replace it with your own figure.
- Effect on the result
- A larger gap reduces how many parts fit in each direction.
- Get it right
- Use the gap your process specification requires; it applies between parts both across and down.
Method and formulas
- Across = floor((rack width + gap) ÷ (part width + gap))
- High = floor((rack height + gap) ÷ (part height + gap))
- Quantity = across × high; repeated with the part rotated
Limitations
- Rectangular envelopes only
- Does not check weight, hooks, drainage or coating access
Typical uses
- Coating, plating or washing rack loading
- Nesting estimates for flat parts
- Comparing rack sizes
Who it is for
- Process engineers
- Coating and finishing supervisors
What you get
- Parts per rack and layout
- Orientation comparison
- Area utilisation
Interpreting the result
- Trial-load a rack before releasing the layout
BIZOMAT tools are screening and decision-support utilities. Verify important financial, engineering, safety, legal or operational decisions using appropriate professional standards and your organisation’s approved data.