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CASE ENGINEERING LAB

Case Builder

Calculate optimal case dimensions for packing inner cartons efficiently. Find the best configuration for known boxes or design cases for target quantities.

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Learn about Case Builder

7 sections including 4 FAQs

The Case Builder optimizes how inner cartons pack into outer cases (shippers). It works in two modes: Known Box mode finds the maximum number of cartons that fit in a given case, while Design for Quantity mode calculates the smallest case needed to hold a target number of cartons. The engine evaluates all valid orientations, packing arrangements, and layer configurations to maximize space utilization.

How it works

Packing Optimization

The Case Builder evaluates every feasible combination of carton orientation (up to 6 rotations) and packing arrangement within the case dimensions. For each configuration, it calculates the number of cartons per layer, number of layers, and total carton count. The engine applies physical constraints — ensuring cartons fit within the case interior dimensions after accounting for clearance and flap overlap.

Design for Quantity

In this mode, the tool works backward from your target carton count to find the smallest case dimensions that accommodate them. It tests standard case size increments and evaluates multiple arrangements to find the most space-efficient solution, balancing cube utilization against practical case proportions.

Example: 12-Pack Wine Bottle Case

Inner carton: 3.5" diameter × 12" tall wine bottle sleeve. Target: 12 bottles in a 3×4 arrangement.

Width = 3 × 3.5" = 10.5", Length = 4 × 3.5" = 14", Height = 12". Adding 0.25" clearance per side and board caliper: case interior = 14.5" × 11" × 12.25".

Cube utilization: (12 × π × 1.75² × 12) / (14.5 × 11 × 12.25) = 1,385 in³ / 1,953 in³ = 70.9%. The tool evaluates whether a 2×6 or 3×4 arrangement is more space-efficient and fits better on standard pallets.

When to use this tool

  • Determining how many retail cartons fit in a master shipper for production planning
  • Designing the optimal shipper size for a new product launch
  • Comparing case configurations to minimize void fill and reduce material costs
  • Verifying case pack counts for warehouse and logistics planning
  • Optimizing cube utilization to reduce shipping costs per unit

Common mistakes to avoid

  • Forgetting to account for case interior dimensions — the internal space is smaller than the external dimensions due to board caliper
  • Not considering carton orientation restrictions — fragile products or labels may require upright-only orientation
  • Ignoring weight limits — a case that fits 24 cartons volumetrically may exceed shipping weight limits
  • Overlooking flute direction requirements for stacking strength — carton flutes should generally be vertical for maximum compression
  • Assuming the tightest pack is always best — some void space can be beneficial for cushioning and easier packing on the production line

Frequently asked questions

What is cube utilization and why does it matter?

Cube utilization is the percentage of the case interior volume actually occupied by inner cartons. Higher cube utilization means less wasted space, less void fill material, and lower shipping costs. A good target is 85-95% cube utilization — below 80% suggests the case is oversized, while above 95% can make packing difficult on production lines.

Should I pack cartons flat or upright?

It depends on the product. For items with a defined "this side up" requirement (liquids, fragile goods), you must maintain upright orientation. For stable products, the tool evaluates all orientations and selects the arrangement with the highest carton count. Flute direction also matters for stacking strength — corrugated is strongest when the flutes run vertically.

What is the difference between Known Box and Design for Quantity modes?

Known Box mode takes your existing case dimensions and tells you the maximum cartons it can hold. Design for Quantity mode does the reverse — you specify how many cartons you need in a case, and the tool calculates the optimal case dimensions. Use Known Box when you have existing inventory, and Design for Quantity for new product development.

How do I account for void fill space?

The Case Builder calculates the theoretical maximum packing density. In practice, you may need to leave some clearance for cushioning, void fill, or easier assembly. A general rule is to allow 5-10mm of clearance on each dimension. If you need significant cushioning, factor that into your inner carton dimensions before running the optimization.

Related

Guide

End-to-End Packaging Planning Workflow

Guide

Material Right-Sizing for Corrugated Cartons and Shippers

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Carton Builder

Design the inner carton before optimizing case packing

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Box/Shipper Builder

Generate detailed shipper specifications

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Box Strength Calculator

Verify the case can handle stacking loads

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Pallet Builder

Optimize how cases arrange on pallets