Depends on item. Best I can answer
At exactly 2 lbs, FedEx/UPS is slightly cheaper. Above 2 lbs, the USPS medium flat rate box is slightly cheaper than FedEx or UPS Ground. The break even point compared to FedEx and UPS for a large Priority Mail flat rate box is about 5 lbs. ... Otherwise, Fedex and UPS will be cheaper for heavier packages. I got this off the internet.
Depends on what your shipping, but usually ups is cheaper.
Thanks! Your answer is awaiting moderation.