Dimensional Weight: Complete Pricing Guide
Dimensional weight (DIM) pricing charges based on package size, not just actual weight. Understanding DIM can save significant money.
What is Dimensional Weight?
| Formula |
|---|
| DIM Weight | (L × W × H) ÷ DIM Factor |
| Billed Weight | MAX(Actual Weight, DIM Weight) |
DIM Factors by Carrier
| Carrier | DIM Factor | Lower = More Expensive |
|---|
| UPS | 139 | Higher DIM charges |
| FedEx | 139 | Higher DIM charges |
| USPS | 166 | Lower DIM charges |
DIM Calculation Examples
Box: 12" × 12" × 12" (1 lb actual)
| Carrier | DIM Weight | Billed | Actual Cost Impact |
|---|
| UPS | 12.4 lbs | 12.4 lbs | Pay for 12+ lbs |
| FedEx | 12.4 lbs | 12.4 lbs | Pay for 12+ lbs |
| USPS | 10.4 lbs | 10.4 lbs | Pay for 10+ lbs |
When DIM Weight Applies
| Carrier | DIM Threshold |
|---|
| UPS Ground | All packages |
| FedEx Ground | All packages |
| USPS Ground | 1+ cubic foot |
| USPS Priority | 1+ cubic foot |
Impact on Costs
| Scenario | Actual | DIM | Cost Difference |
|---|
| Light in large box | 2 lbs | 15 lbs | +$12-18 |
| Pillows | 3 lbs | 25 lbs | +$20-30 |
| Clothing oversized | 1 lb | 10 lbs | +$8-12 |
Strategies to Reduce DIM
1. Right-Size Packaging
| Product Type | Optimal Box |
|---|
| Small items | Smallest that fits |
| Soft goods | Poly mailer |
| Multiple items | Custom sizing |
| Box (1 lb item) | Mailer (1 lb item) |
|---|
| 12×10×4 = 2.9 lbs DIM | No DIM charge |
| $9.50 shipped | $5.50 shipped |
| +73% cost | Baseline |
| Method | DIM Reduction |
|---|
| Vacuum bags | 50-70% |
| Compression straps | 20-40% |
| Tight folding | 10-20% |
| Standard Box | Custom Box | DIM Savings |
|---|
| 14×14×14 | 10×10×10 | 64% |
| 18×18×12 | 16×14×8 | 54% |
| 20×16×12 | 18×12×10 | 44% |
USPS Cubic Pricing Advantage
For packages under 0.5 cubic feet, USPS Cubic ignores weight:
| Cubic Tier | Max Dimensions | Rate |
|---|
| 0.1 | 4×4×4 | ~$6.50 |
| 0.2 | 5×5×5 | ~$7.25 |
| 0.3 | 6×6×5 | ~$8.50 |
| 0.4 | 7×7×5 | ~$9.75 |
| 0.5 | 8×6×5 | ~$11.00 |
Packaging Cost vs DIM Savings
| Investment | Annual Savings |
|---|
| Custom boxes | $2,000-10,000 |
| Poly mailers | $5,000-25,000 |
| Compression | $1,000-5,000 |
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