Free shipping cost calculator
Cheapest way to ship a package
Enter your package’s size and weight to compare USPS Flat Rate boxes with USPS Ground Advantage and Priority Mail prices in every zone, see which is cheapest where, then get live USPS, UPS and FedEx rates for the exact route.
Your package
Flat Rate vs. weight-based USPS prices
Enter the package size and weight to compare USPS options.
How to find the cheapest shipping option
Weigh and measure the packed box
Use the outside dimensions of the box you will ship and its weight with packing.Compare by zone
Weight-based prices rise with distance; Flat Rate doesn’t. The table highlights the cheapest option in each zone.Check dimensional weight
If your box is large and light, a smaller box can lower the price more than any carrier switch.Get the live rate
Live rates include UPS and FedEx and your exact origin and destination.
Shipping cost terms
- Commercial price
- The discounted USPS price for postage bought online through a shipping platform.
- Billable weight
- The greater of actual and dimensional weight, rounded up, that the carrier charges for.
- Flat Rate
- One price per box or envelope to any US address, regardless of weight up to 70 lb.
- Zone
- Distance band between origin and destination ZIP Codes used to price weight-based services.
Cheapest shipping FAQ
- What is the cheapest way to ship a package?
- For most packages under about 1 lb, USPS Ground Advantage is the cheapest option. For heavy, compact items going a long distance, a Priority Mail Flat Rate box is often cheaper because the price ignores weight. For large, light boxes, compare UPS and FedEx Ground too, since dimensional weight changes the math. Enter your package to compare.
- How much does it cost to ship a package?
- With USPS commercial (online) prices right now, a 1 lb package costs about $8.01 to $11.22 by USPS Ground Advantage depending on the zone, and a 5 lb box about $10.35 to $20.24. A Medium Flat Rate Box is $22.02 to any US address. Counter (retail) prices are higher.
- When is USPS Flat Rate worth it?
- When your item is heavy, fits the box, and is going to a far zone. A 12 lb item that fits a Medium Flat Rate Box costs $22.02 anywhere, while weight-based services for 12 lb rise steeply in zones 5–8.
- What is a shipping zone?
- USPS, UPS and FedEx price by zone, a measure of distance from the origin ZIP Code. Zone 1–2 is local and zone 8 is the farthest in the contiguous US. Flat Rate prices do not depend on zone.
- Why does box size change the price?
- Packages over 1 cubic foot are billed by dimensional weight (length × width × height ÷ 139) when it is more than the actual weight, and long or bulky parcels pay extra fees. A snug box keeps the billable weight down.
- Is it cheaper to ship online than at the Post Office?
- Usually yes. Online postage uses USPS commercial prices, which are lower than retail counter prices for most services, including Flat Rate.
Compare every carrier
Live USPS, UPS and FedEx rates for your exact route, with discounted labels.
Free tools
More free shipping tools
USPS Box Sizes
Every USPS Flat Rate box and envelope size with prices, plus a box finder.
Box Size Calculator
Find the smallest box for your items, its DIM weight and Flat Rate boxes that fit.
Dimensional Weight Calculator
Find the billable DIM weight carriers will charge before the invoice lands.
Delivery Time Estimator
Estimate transit days by carrier and service to set checkout promises.
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Request a free auditPrices are USPS published commercial prices (holiday period through 2027-01-17) and are estimates; your actual rate depends on the exact addresses, packaging and surcharges. ShipWave is not affiliated with or endorsed by the United States Postal Service; USPS, Priority Mail and USPS Ground Advantage are its trademarks.