The problem
Shipping costs are not one number
Most people think of a shipping cost as a single charge. In reality, it's a stack of components — base rate, surcharges, fees, and adjustments — that combine to form the final billed amount. Without understanding each layer, you can't control the total.
A single shipment can include 5–15 separate charge components, from base rate to address correction to peak surcharge.
Surcharges are applied after shipment and don't appear in rate card estimates, creating invoice surprises.
Fuel surcharges alone can add 10–15% to every package, and the rate changes frequently.
Carriers apply surcharges based on their own data (address type, package measurements), which may differ from yours.
Most shipping platforms show a total cost but don't break it down into the individual charge components.
How it works
The anatomy of a shipping charge
Every shipping cost is made up of distinct components. Here's what they are and how they affect your final bill.
Base rate
The core shipping charge based on service level, weight (or DIM weight), and origin-to-destination zone. This is the number your rate card shows.
DIM weight pricing
Carriers calculate a "dimensional weight" based on package volume. If DIM weight exceeds actual weight, you're billed at the higher amount.
- Formula: (L × W × H) ÷ DIM factor
- FedEx/UPS DIM factor: typically 139
- USPS DIM factor: 166 (Priority Mail)
Fuel surcharge
A percentage applied on top of the base rate that fluctuates with fuel costs. Updated weekly by FedEx and UPS, it typically ranges from 6% to 15%.
Residential surcharge
An additional fee ($4–$6+) when the delivery address is classified as residential. Carriers make this determination independently.
Address correction
If the carrier corrects the delivery address (zip code, suite number, city), a fee of $12–$20 is applied per package.
Peak & demand surcharges
Seasonal surcharges during high-volume periods (typically October–January). These can add $1–$6+ per package on top of all other charges.
- Holiday peak surcharge
- Demand surcharge (volume-based)
- Large package surcharge
- Additional handling surcharge
How RateRunners helps
See every charge, fully explained
RateRunners surfaces each cost component in one shipment-level financial record — so you can see exactly what you were charged and why.
View the full cost breakdown for every shipment in one place
See base rate, surcharges, and adjustments as separate line items
Compare each component to your expected cost from the rate card
Identify which surcharges are driving cost increases across your operation
Track surcharge trends over time to negotiate better carrier contracts
Export detailed cost breakdowns for financial reporting and auditing
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