Cheapest Way to Ship a 5 lb Package

Five pounds represents a strategic inflection point in shipping economics. It's heavy enough that carrier differences become meaningful, yet light enough to access USPS's competitive pricing. For e-commerce businesses, optimizing 5 lb shipments often yields the highest ROI in shipping cost reduction.

At 5 lbs, the pricing gap between carriers is substantial:

• USPS Ground Advantage: $7.00-$9.50
• UPS Ground: $14.50-$18.00
• FedEx Ground: $14.95-$18.50

The 50%+ savings with USPS makes it the default choice for most shippers. However, several specialized options compete for the "cheapest" title depending on your package dimensions and destination.

Priority Mail Cubic truly shines at 5 lbs. Since Cubic pricing ignores weight (up to 20 lbs), a 5 lb package in a compact box costs the same as a 2 lb package in the same size box. For dense products like books, hardware, or fitness equipment, Cubic can undercut even Ground Advantage while providing faster delivery.

This weight class also benefits from Regional Rate boxes - a lesser-known USPS option that combines the simplicity of Flat Rate with zone-based savings for regional shipments.

USPS Priority Mail Regional Rate boxes are perhaps the most underutilized option for 5 lb packages. These special boxes use zone-based pricing (like regular Priority Mail) but at discounted rates - often 20-30% cheaper than standard Priority Mail.

There are two sizes relevant to 5 lb shipping:

• Regional Rate Box A: Up to 15 lbs, approximately 10" x 7" x 4.75". Costs $9.35-$12.85 based on zone.
• Regional Rate Box B: Up to 20 lbs, approximately 12" x 10.25" x 5". Costs $11.15-$16.40 based on zone.

For 5 lb packages shipping within your region (zones 1-4), Regional Rate Box A often beats Ground Advantage by a dollar or more while providing 1-3 day Priority Mail service. The boxes are free from USPS - you're just paying for the shipping.

The catch: Regional Rate is only available through commercial shipping software, not at the post office. Platforms like ShipWave include Regional Rate as an automatic option, selecting it when it's the cheapest Priority-speed service.

Many sellers don't know Regional Rate exists, which means you can offer faster shipping than competitors at equal or lower cost by leveraging this option strategically.

While UPS and FedEx published rates for 5 lb packages hover around $14-18, high-volume shippers can negotiate significantly better pricing. Understanding these negotiations helps you know when UPS/FedEx becomes competitive.

Volume Thresholds: UPS and FedEx typically start offering discounts at 100+ packages weekly. At 500+ weekly, discounts can reach 40-50% off published rates. At these levels, a $15 UPS Ground shipment might cost $8-9 - approaching USPS Ground Advantage pricing.

Zone-Based Leverage: If your shipments concentrate in certain zones, you can negotiate zone-specific discounts. A California-based seller shipping primarily to West Coast customers might get better zone 1-3 rates than national rates.

Service Mix Matters: Agreeing to use a certain percentage of premium services (like Express or 2-Day) can lower your Ground rates. Carriers want your express business and will discount ground to get it.

For shippers under 100 packages weekly, USPS remains the clear 5 lb winner. But if you're scaling, request UPS and FedEx rate quotes around the 500 weekly package mark - you might be surprised at the offers.