Case Study: From Oversized to Optimized — How One Store Cut Shipping Costs 28%
A home goods store shipping 3,500 orders/month reduced shipping costs by 28% ($11,200/month) by implementing systematic box optimization. The key changes: expanding from 3 box sizes to 8, implementing automated box recommendations, and training staff on DIM weight impact. Damage claims dropped 65% as a side benefit. Total implementation cost was under $2,500 upfront, with ROI achieved in 7 days. The transformation required no carrier changes, no rate negotiations, and no major operational overhaul—just smarter packaging decisions for every order.

When Sarah Chen launched her home goods store, she did what most founders do: she ordered a few box sizes, trained her team to "use whatever fits," and focused on the parts of the business she understood—products, marketing, and customer experience.
Eighteen months later, her shipping costs were eating her margins alive. What changed?
This case study walks through how a mid-size Shopify store transformed their packaging operations, cutting shipping costs by 28% and reducing damage claims by 65%—without changing carriers or negotiating new rates.
The Company Profile
Before Optimization
| Metric | Value |
|---|---|
| Monthly orders | 3,500 |
| Average order value | $85 |
| Monthly revenue | $297,500 |
| Monthly shipping cost | $39,900 |
| Shipping as % of revenue | 13.4% |
| Industry benchmark | 12-15% |
On paper, they looked fine. But the details told a different story.
Product Mix
| Category | % of Orders | Avg Weight | Avg Size |
|---|---|---|---|
| Decorative items | 35% | 1.5 lbs | 8×6×4" |
| Kitchen goods | 30% | 2.5 lbs | 10×8×6" |
| Textiles | 20% | 1 lb | 12×10×4" |
| Fragile items | 15% | 2 lbs | 6×6×6" |
The Packaging Setup (Before)
| Box Size | Dimensions | When Used |
|---|---|---|
| Small | 10×8×6" | "Small items" |
| Medium | 14×12×10" | "Most items" |
| Large | 18×14×12" | "Large items" |
Three box sizes for 400+ SKUs. The math didn't work.
The Problem Discovery
The Audit Process
Sarah's operations manager conducted a one-week audit:
Day 1-3: Random sampling
- Pulled 100 random orders
- Measured products vs boxes used
- Calculated actual box utilization
Day 4-5: Data analysis
- Reviewed shipping invoices
- Identified patterns in carrier charges
- Compared actual vs DIM weight
Day 6-7: Root cause identification
- Interviewed packing team
- Documented box selection process
- Identified decision points
What They Found
Box utilization was abysmal:
| Box Size | Avg Utilization | Result |
|---|---|---|
| Small | 55% | Usually undersized, forced to medium |
| Medium | 38% | Most common choice, rarely optimal |
| Large | 25% | Massive waste |
72% of orders shipped in the "Medium" box because:
- It "fit everything"
- Packers defaulted to it when unsure
- No guidance on when to use alternatives
The Real Numbers
Sample of 100 orders analyzed:
| Metric | Value |
|---|---|
| Average actual weight | 2.1 lbs |
| Average DIM weight | 7.8 lbs |
| Average billable weight | 7.8 lbs |
| % billed at DIM weight | 89% |
| Average DIM waste | 5.7 lbs |
They were paying for 5.7 pounds of air per order.
Cost Impact Calculation
` DIM waste per order: 5.7 lbs Average cost per lb (Zone 4-5): $0.95 Waste per order: $5.42 Monthly orders: 3,500 Monthly DIM waste: $18,970 `
Nearly $19,000 per month in pure DIM weight waste.
The Transformation Plan
Phase 1: Box Inventory Expansion (Week 1)
New box selection:
| Box # | Dimensions | Primary Use |
|---|---|---|
| 1 | 6×4×4" | Small accessories |
| 2 | 8×6×4" | Decorative items |
| 3 | 10×8×4" | Flat items, textiles |
| 4 | 10×8×6" | Kitchen goods (small) |
| 5 | 12×10×6" | Kitchen goods (medium) |
| 6 | 14×10×8" | Multiple items |
| 7 | 16×12×8" | Large items |
| 8 | 18×14×10" | Fragile/special handling |
Cost: $1,200 for initial inventory of 8 sizes
Phase 2: Box Recommendation System (Week 2)
Implementation:
| Action | Time | Cost |
|---|---|---|
| Install box recommendation app | 1 hour | $99/month |
| Configure product dimensions | 8 hours | Staff time |
| Test recommendations | 4 hours | Staff time |
| Integrate with packing workflow | 2 hours | Staff time |
Total implementation time: ~15 hours
Phase 3: Team Training (Week 2-3)
Training focus:
| Topic | Duration | Format |
|---|---|---|
| Why DIM weight matters | 30 min | Group session |
| How to use recommendations | 1 hour | Hands-on |
| Exception handling | 30 min | Q&A |
| Quality check process | 30 min | Demo |
Training cost: $500 (staff time during training)
Phase 4: Process Refinement (Week 4-8)
Ongoing optimization:
| Activity | Frequency |
|---|---|
| Review override rate | Daily |
| Analyze DIM performance | Weekly |
| Adjust product dimensions | As needed |
| Retrain on issues | Monthly |
The Results
Immediate Impact (Week 1-4)
| Metric | Before | After Week 4 | Change |
|---|---|---|---|
| Avg box utilization | 42% | 68% | +26 pts |
| Avg DIM weight | 7.8 lbs | 4.2 lbs | -3.6 lbs |
| Avg shipping cost | $11.40 | $9.10 | -$2.30 |
| Damage rate | 3.2% | 1.8% | -1.4 pts |
Sustained Results (Month 3)
| Metric | Before | After Month 3 | Change |
|---|---|---|---|
| Avg box utilization | 42% | 74% | +32 pts |
| Avg DIM weight | 7.8 lbs | 3.4 lbs | -4.4 lbs |
| Avg shipping cost | $11.40 | $8.20 | -$3.20 |
| Damage rate | 3.2% | 1.1% | -2.1 pts |
Financial Impact
| Category | Monthly | Annual |
|---|---|---|
| **Shipping cost before** | $39,900 | $478,800 |
| **Shipping cost after** | $28,700 | $344,400 |
| **Direct savings** | $11,200 | $134,400 |
| **Damage claim reduction** | $2,100 | $25,200 |
| **Total savings** | $13,300 | $159,600 |
ROI Calculation
| Investment | Cost |
|---|---|
| Box inventory | $1,200 |
| App subscription (annual) | $1,188 |
| Training time | $500 |
| Implementation time | $400 |
| **Total Year 1 cost** | **$3,288** |
| Return | Value |
|---|---|
| Year 1 savings | $159,600 |
| Investment | $3,288 |
| **Net benefit** | **$156,312** |
| **ROI** | **4,754%** |
Payback period: 7 days
What Made It Work
Success Factor 1: Data-Driven Discovery
The audit revealed the problem clearly:
- 89% of orders billed at DIM weight
- 5.7 lbs average waste per order
- $19,000 monthly in pure waste
Without data, optimization would have been guessing.
Success Factor 2: Right Box Selection
Eight sizes vs three wasn't random:
- Mapped to actual product dimensions
- Covered 95% of order combinations
- Left room for exceptions without default to "medium"
Success Factor 3: System-Driven Decisions
Removing human judgment:
- Before: Packers chose boxes based on experience
- After: System recommended, packers executed
Override rate dropped from N/A to 8% within two months.
Success Factor 4: Consistent Training
Everyone understood why:
- DIM weight economics explained
- Personal stake communicated (company health)
- Regular reinforcement prevented drift
Success Factor 5: Continuous Monitoring
Weekly reviews caught issues:
- New products added with dimensions
- Override reasons analyzed
- System recommendations refined
The Unexpected Benefits
Benefit 1: Faster Packing
| Metric | Before | After |
|---|---|---|
| Avg pack time per order | 3.5 min | 2.8 min |
| Decision time | 45 sec | 5 sec |
| Orders per hour per packer | 17 | 21 |
Removing decisions sped everything up.
Benefit 2: Better Customer Reviews
Before optimization:
- 4.2 average review rating
- 12% mentions of "packaging" in negative reviews
After optimization:
- 4.5 average review rating
- 4% mentions of "packaging" in negative reviews
Benefit 3: Reduced Material Costs
| Material | Monthly Before | Monthly After | Savings |
|---|---|---|---|
| Void fill | $890 | $520 | $370 |
| Tape | $180 | $140 | $40 |
| Boxes | $2,100 | $2,400 | -$300 |
| **Net** | $3,170 | $3,060 | **$110** |
Slightly higher box costs offset by major void fill reduction.
Benefit 4: Environmental Credentials
Marketing opportunity:
- "Right-sized packaging" messaging resonated
- Reduced waste became brand differentiator
- Customer feedback positive
Lessons Learned
Lesson 1: The Problem Wasn't Carrier Rates
Initial assumption: "We need to negotiate better rates."
Reality: Rate negotiation would have saved 5-10%. Box optimization saved 28%.
Lesson 2: Three Box Sizes Is Never Enough
The "simplicity" of few box sizes creates complexity:
- Packers constantly make judgment calls
- Default to bigger = constant waste
- No good option for many orders
Eight sizes eliminated most decisions.
Lesson 3: System Beats Training
Training packers to "choose wisely" doesn't scale:
- New hires don't have institutional knowledge
- Peak season temps can't be fully trained
- Fatigue affects judgment
Automated recommendations work 24/7.
Lesson 4: DIM Weight Is the Biggest Lever
For most e-commerce (light, bulky products):
- Carrier rate differences: 10-20%
- DIM weight optimization: 25-40%
Optimize the bigger lever first.
Lesson 5: Quick Wins Build Momentum
7-day payback meant:
- Leadership bought in immediately
- Team saw results quickly
- Enthusiasm for continued optimization
Implementation Template
If You Want Similar Results
Week 1:
- [ ] Audit 50-100 orders (measure products vs boxes)
- [ ] Calculate current box utilization
- [ ] Determine DIM weight vs actual weight ratio
- [ ] Calculate monthly waste in dollars
Week 2:
- [ ] Design optimal box size selection
- [ ] Order new box inventory
- [ ] Evaluate box recommendation solutions
Week 3:
- [ ] Implement recommendation system
- [ ] Configure product dimensions
- [ ] Train packing team
Week 4:
- [ ] Go live with new process
- [ ] Monitor daily for issues
- [ ] Track improvement metrics
Ongoing:
- [ ] Weekly utilization review
- [ ] Monthly process refinement
- [ ] Quarterly comprehensive audit
Frequently Asked Questions
Can we achieve similar results with different products?
DIM weight optimization works best for lightweight, bulky products (apparel, home goods, toys). Dense products (electronics, books) may see smaller improvements—but improvements nonetheless.
What if we have thousands of SKUs?
Start with your top 100 SKUs by volume. They likely represent 60-80% of orders. Add others over time. The system learns and improves.
Do we need to change carriers?
No. This case study achieved 28% savings without changing carriers or negotiating rates. Carrier optimization can stack on top of packaging optimization.
How long do results take?
Immediate improvement from day one. Full optimization takes 60-90 days as you refine dimensions and train team. The 28% result here was achieved by month 3.
What if our team resists change?
Show them the math. When packers understand that oversized boxes cost the company $5+ each, and that their job security depends on company profitability, resistance typically fades.
Sources & References
- [1]Packaging Optimization ROI - Packsize (2024)
- [2]DIM Weight Impact Studies - UPS (2025)
- [3]E-commerce Fulfillment Benchmarks - ShipBob (2024)
Attribute Team
The Attribute team combines decades of e-commerce experience, having helped scale stores to $20M+ in revenue. We build the Shopify apps we wish we had as merchants.