Since updating my store last night, I've noticed that shipping rates (especially USPS) are way off when ordering multiples of something.

Example Product:
One product has the dimensions in our admin as 42"x17"x1" and weighing 2.1 lbs. and costs $39.99.

Step 1: Adding 1 to our cart and estimating from zip 49509 to 02779 gives us $13.59 on our site. USPS' non-commercial public rate is $11.65. We have a 3.75% handling fee, so there's a little difference in the price because of that. This calculation is 100% correct, nothing is wrong.

Step 2: Adjusting the quantity from 1 of this product to 2 increases the shipping on our site from $13.59, to $17.68. This is a reasonable jump in price due to the added weight. We're now at 4.2 lbs in weight, and should still be at the 42"x17"x1" size, to my knowledge. USPS' rate is $14.15, and again there's a small upcharge with the handling percentage. This calculation is also 100% correct, nothing is wrong.

Step 3: Adjusting the quantity from 2 of this product to 3 increases the shipping on our site from $17.68, to $35.40 !! To my knowledge, a quantity of 3 of this product should be returning a rate for a 42"x17"x1" package weighing 6.3 lbs. The 7lb rate for a package that is 42"x17"x1" is $18.05, which is a reasonable incremental increase, but at this point there is clearly something wrong with the data being sent for the rates to return something almost double. This calculation is WAY off, it is wrong.

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Any help with this is much appreciated. I ran a few different products and zip codes, and single quantity items are close but when it starts getting into multiples of an item is when it gets out of whack.

Pack Products is set to "Pack products together"
Shipping weights are in LBS
Dimensions are set to IN
Handling Charge is 0
Handling Charge (Percentage) is 3.75%
I don't believe I have any abnormal parameters in my includes file that would be creating this behavior.

Check to see what you have set in your admin main setting for
"Select how you pack products, for shipping calculations.
(Only affects UPS, FedEx, USPS, Weight and Price based shipping)"

Perhaps it's set to "pack products separately" and you need to change that to "pack products together"

If that is the case, you probably want to set (in your includes) what is the max weight you normally make a box.
https://www.ecommercetemplates.com/help/ecommplus/parameters.asp#split



David
ECT Power User

Dave, in my initial post, I outlined a few things in the admin.

I wrote:

"Pack Products is set to "Pack products together"
Shipping weights are in LBS
Dimensions are set to IN
Handling Charge is 0
Handling Charge (Percentage) is 3.75%
I don't believe I have any abnormal parameters in my includes file that would be creating this behavior."

Also, I don't have anything set for either "splitpackat" or "nosplitlargepacks" because these are generally not large or heavy. This seems to be mainly affecting USPS, FedEx rates come back as much more reasonable.

Sorry, I didn't read thoroughly enough...

I think you are assuming the dimensions are staying the same as products are added and I don't think that is the case.
Your dimensions whould be tripled.

Think like this.
A product is in it's own box and that box is 3" x 3"
If you have three of them, the how is the shipping box still 3" x 3"
That's really impossible.

Each of your products is in it's own box that is 3" x 3" then that is 9 cubic inches. Three of them will be a box that holds 27 cubic inches at least. (9 x 3)


David
ECT Power User

I assumed that by packing the items together that it would take the largest dimension item and base the rate from that.

If that's not the behavior then:

1) It would be nice to have an option to get that type of package combining. Many of our items are in fair sized boxes (such as a 36"x12"x4") yet contain items that stack very well. We could easily put (10) of the same item in the 36"x12"x4" box, yet it's potentially being calculated as 36"x12"x40" which really throws off the shipping costs. Reducing the listed size of the package is not the correct course of action for us, as many of our boxes we use are borderline oversized with some being a little over and some being a little under.

2) Would be nice to know which of the 3 dimensions is being added. IE, is (2) 42"x17"x1" packages:
a) 84" x 17" x 1"
b) 42" x 34" x 1"
c) 42" x 17" x 2"

I believe the measurements are going to be calculated as cubic inches. Like I suggest in my earlier post. I just realize I didn't do that right, but 3" x 3" x 3" = 27 cubic inches multiplied by how many of that item. But also the max size must be taken into account, because there are rules regarding max dimensions.
I know UPS and FEDEX use cubic inches to determine dimensional weight.

It seems you have actually listed the box size you ship an item in, rather than the actual space your product takes up.
If you combine items into one box, the scenario you are using does not work well and results in inflated shipping quotes when customers order multiples.

I think you will find things fall into place if you set the actual dimensions of the products and set a few of the parameters I mentioned before.

David
ECT Power User

What parameters did you suggest that would help my situation?

We sell some items that:
- weigh 1 oz & 3"x1"x1", and can go 1st class mail.
- weigh 3 lbs & 42"x17"x1" in a package that is also 42"x17"x1" (very form fitting package), and can go priority mail.
- weigh 7 lbs & 42"x13"x2" in a package that is 44"x15"x5", and is oversized based on USPS' length + girth rules.

In the case of the 42"x13"x2", I can't measure it at the product size because it would charge way less than it should, but at the same time, we can pack two together.

The best solution for me, would be if there was a parameter to calculate the dimensions based on the largest item and based the weight off the sum of the whole of products. That's currently not an option but I am offering this as a suggestion for a future option.

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I have the same issues with weights. Something I've suggested a few times is to have two different product weights in the product admin
1) The initial weight if a customer is purchasing one of the item
2) The weight for additional units of the same item

Also, the ability to restrict certain products from certain shipping services and also from certain countries would be a great feature. All too often we have customers purchase a product which is hazardous and use a shipping service that cannot be used for that product.

It would be nice to have more control over this type of stuff so we can get more accurate shipping rates.

I sell a tiny item that weighs less than a piece of paper, and we have a not so heavy item that is 45" long and we have dense heavy items that is about 1 cubic foot and weighs 35 pounds.
All of our calculations are pretty well correct.

The difference is, I do not use any dimensions. Just weights.

Sometimes we are a little bit off, but you will never get it perfect on every item when you are asking for rates from the carriers.
Shipping costs versus revenue have to be looked at over a broad time frame to see how things are working.

You might set dimensions to "do not specify" in your admin and run some test orders to see if things are better.

I use the Initial pack weight parameter set at .3 to account for average box weight.
I also have splitpackat, set to 40 (pounds), even though we do make boxes up to 50 or more pounds sometimes.

Give it a try. It sounds like it may work for you.

David
ECT Power User

Yes, I understand those parameters and I have played around with those in the past and they did not work well for me. That is why I have made the suggestions that I have. I'd be willing to pay for these features, and I'd wager there are others whom would make use of additional control over weights and dimensions.