
The United States Postal Service (USPS) is one of the largest and most trusted delivery networks in the world, delivering billions of mail pieces and packages each year across the United States. USPS is known for its nationwide coverage, competitive pricing, and reliable residential delivery—making it a popular choice for e-commerce shipments.
Deliveri supports several USPS service classes to help you balance cost, speed, and package size.

Estimated delivery speed:
1–3 business days
Best for:
Fast, affordable delivery for most lightweight to mid-weight packages.
Key characteristics:
Nationwide delivery within 1–3 business days
Includes USPS tracking
Free USPS packaging available
Residential delivery included
Saturday delivery available in many areas
Priority Mail is one of the most commonly used USPS services due to its balance of speed and cost.

Estimated delivery speed:
1–2 business days (often overnight to many locations)
Best for:
Time-sensitive or urgent shipments.
Key characteristics:
Fastest USPS service
Delivery available 7 days a week in many locations
USPS tracking included
Money-back service guarantee (when applicable)
Priority Mail Express is ideal when speed is more important than cost.

Estimated delivery speed:
2–5 business days
Best for:
Cost-effective shipping for non-urgent packages.
Key characteristics:
Designed for affordable ground shipping
Includes USPS tracking
Residential delivery included
Replaces several legacy USPS ground services
Ground Advantage is a strong option for heavier packages or shipments where delivery speed is flexible.
CubicEstimated delivery speed:
2–5 business days
Best for:
Small, heavy packages where size matters more than weight.
Key characteristics:
Pricing is based on package volume, not weight
Often cheaper than standard Ground Advantage for dense shipments
Includes USPS tracking
Residential delivery included
Ground Advantage Cubic is ideal for compact packages with higher weights.
CubicEstimated delivery speed:
1–3 business days
Best for:
Small, dense packages that need faster delivery.
Key characteristics:
Priority Mail speed with cubic (volume-based) pricing
Lower cost than standard Priority Mail for small packages
USPS tracking included
Residential delivery included
Priority Mail Cubic is a popular choice for e-commerce brands shipping small but heavy items quickly.
Service Class | Estimated Delivery Speed | Pricing Basis | Best For | Notable Characteristics |
Priority Mail | 1–3 business days | Weight & distance | Everyday fast shipping | Most popular USPS service, good balance of speed and cost |
Priority Mail Express | 1–2 business days (often overnight) | Weight & distance | Urgent shipments | Fastest USPS option, delivery available 7 days/week in many areas |
Ground Advantage | 2–5 business days | Weight & distance | Cost-sensitive shipping | Affordable ground option, residential delivery included |
Ground Advantage | 2–5 business days | Small, heavy packages | Cheaper than weight-based ground for dense shipments | |
Priority Mail | 1–3 business days | Small, heavy packages that need speed | Priority Mail speed with lower cubic pricing |
All USPS delivery times are best estimates, not guarantees (unless explicitly stated)
Delivery times may be affected by:
Weather conditions
Natural disasters
Holidays
Carrier network delays
Other unforeseen circumstances
Always plan shipping timelines with flexibility in mind.
Fastest delivery: Priority Mail Express
Best balance of speed and cost: Priority Mail
Lowest cost for flexible delivery: Ground Advantage
Best for small, heavy packages: Cubic services
Deliveri automatically helps you compare USPS services so you can choose the best option for each shipment.