This is a question I get almost everyday! While the answer depends heavily on 3 factors (size, weight, and distance) there are some ranges you can use to estimate costs!
Less Than 1 Pound
Packages less than 1 pound can be sent via USPS for around $3-$5.
If you are working with a fulfillment center and want to use UPS or FedEx you should see rates around $8-$9 for these packages.
USPS definitely wins with price in this category, but as always the service is always a little less.
1-5 Pounds
In this range UPS and USPS are almost the same. To get the UPS rates needed to be competitive you’ll need to either be doing a lot of packages and negotiate a rate directly with UPS or work with a 3PL who has already negotiated those rates.
Pricing here will be between $8-$15. Again this is a HUGE estimate. You can pay more if your product is big or the package is going to Hawaii or Alaska. This is only meant to be a guess for you to use as you work on calculating rough costs for US shipping.
FedEx can get close but tends to run $11-$20 in this range so they are worth looking at but not the cheapest in this range.
5+ Pounds
Now this range is HUGE. a 5 pound product and an 80 pound product are going to cost very different prices. I won’t be listing a price here due to the huge range, but I will list out who tends to be cheaper.
FedEx really dominates this space. FedEx beats UPS pricing by amount 10-20% in most cases.
AVOID USPS. They are SUPER expensive and don’t do well with big packages. If your fulfillment partner is suggesting USPS on packages this heavy or big, change partners.