USPS not calculating correct and free ship info.

hello, I have noticed with customers have been choosing usps during checkout, now I used usps to calculate a test shipment and it comes up for priority mail : $14.40 and on my site it says $10.55 ($1.00 handeling fee) so overall usps on my site really: $9.55 thats a about a 4-5 dollar difference. Its at 2.24 lbs and have tried it with other weights and is still off. Anyone help me out?

I offer free shipping for order on $50 but they have to weigh less than 15lbs.... I got an order that was only 3lbs and total was $51.99.. shipped it usps parcel for $8.36! Their prices are terrible anymore. I made 0% profit. I only offer this free shipping as a promotion for my site, the products i sell I try to have low prices to also catch the customer the two together isn't working. Suggestions please. What do you do?

The only reason i offer usps is because i didn't want my customer to have to pay a ridiculous amount for a single item... my supplier ships for me but its it starts at $10 1-2 pounds 11 for 3-4 etc for anywhere in the usa

Anyone help me out please, even if you don't know to the first part comments for the second part thanks

What are the settings in the Configuration ... Shipping/Packaging ...

What are the settings for the USPS shipping module?

What is the Ship From address?

What is the Ship To address?

USPS:
Enable USPS: True
Which Server to use: Production
Handeling Fee: $1.00
Shipping zone: none
All Packages are Machinable: True
USPS options: Disply Rate, Disply transit time
Domestic Shipping Methods: PRIORITY
International Shipping Methods: --none--
Debug Mode: Off

Shipping/Packaging:
Country of Origin: United States
Postal Code: My Zip
Enter the Maximum Package Weight you will ship: 65
Package Tare Small to Medium - added percentage:weight: 2:0
Larger packages - added packaging percentage:weight" 5:0
Display Number of Boxes and Weight Status: 2
Order Free Shipping 0 Weight Status: 0
Shipping Estimator Display Settings for Shopping Cart: 1
Display Order Comments on Admin Invoice: 2
Display Order Comments on Admin Packing Slip: 2

zip codes I have tried multiple different ones comparing to my site and to the usps calculator on their site and they are not even.

These settings that you have:

Enter the Maximum Package Weight you will ship: 65
Package Tare Small to Medium - added percentage:weight: 2:0
Larger packages - added packaging percentage:weight" 5:0

Mean that the Maximum weight per package is 65 lbs ... be aware that 70lbs is the maximum and anything over the 70lbs will not obtain a quote ... the weight being the Order weight plus the Tare weight ...

You have Small packages adding a Tare of 2:0 which means to add 20% of the weight to the Order for packaging ...

You have Medium to Large packages adding a Tare of 5:0 which means to add 50% of the weight to the order for packaging ...

So a 10lbs package is quoting for 12lbs ... anything that is over 65lbs will be divided into separate boxes and add 50% of the weight to each box ...

Then, you are also adding the Handling Fee of $1.00 on top of all of this ...

And of course while wanting to test the results ... USPS server is down right now and I cannot test anything ... :blink:

Meanwhile, make sure that you have the current USPS shipping module installed and have followed all of the instructions:
http://www.zen-cart.com/forum/showthread.php?t=97461