Help with tare weights

[isaacr25]

I''m in the process of setting up my shipping module, and I don't quite understand tare weights and how they work. I need to be sure that I'm not over-charging or under-charging for shipping. Can someone please explain (or post a link to a good explanation) tare weights and its relationship to shipping charges? Thanks in advance.

[Ajeh]

I take my 1lbs item and stick in a box ... box weighs 1lb and then put in the packing matterials another .5lbs and the tape etc.

Currently the default is 3lbs ... as an "average" tare weight ... your tare weight may differ or you may decide not to use one at all ...

[isaacr25]

How does that relate to the setting in Configuration >>> Shipping/Packaging?

[Ajeh]

The settings on small/medium and large are set according to the weight of the order ... and how the boxes divide up ...

If you ship up to 50 lb boxes then <=50 is considered small/medium and larger such as 75 lbs is considered large box ...

Once divided up on the weight, that Tare is factored in per box ...

So a 1lb item with a 3lb Tare is a 4lb box ... and will get a 4lb quote ...

[isaacr25]

Ok,
The heaviest item I ship weights 12lbs. The packaging adds at most 1lb. Most of the items I ship weigh from 1 to 3lbs. Again the packaging for these weigh at most 1lb.

I'm a bit confused about the logic to be used for the setting:

What is the weight of typical packaging of small to medium packages?
Example: 10% + 1lb 10:1
10% + 0lbs 10:0
0% + 5lbs 0:5
0% + 0lbs 0:0

[Ajeh]

10:2 means you would be adding 10% plus 2 lbs to the weight ...

0:3 means you would be adding 0% plus 3 lbs to the weight ...

0:0 means you would be adding 0% plus 0 lbs to the weight ...

[DieuxSoldat_04]

I am doing a search on Tare weights and I found this thread. I think both the original author and I still do not understand.

We do comprehend what you mean by:

10:2 means you would be adding 10% plus 2 lbs to the weight ...

0:3 means you would be adding 0% plus 3 lbs to the weight ...

0:0 means you would be adding 0% plus 0 lbs to the weight ...

but we do not understand the logic, I suppose. For instance, does the quote mean there will be a 10% extra charge for every 2 pounds of shipping or for every 2 pounds, 10% of the total price is the shipping charge?

I have read a few threads and haven't found any that had someone willing to describe it carefully or rather in laymen terms for those who are lacking experience in this field,

[mauryg]

The settings on small/medium and large are set according to the weight of the order ... and how the boxes divide up ...

If you ship up to 50 lb boxes then <=50 is considered small/medium and larger such as 75 lbs is considered large box ...

Once divided up on the weight, that Tare is factored in per box ...

So a 1lb item with a 3lb Tare is a 4lb box ... and will get a 4lb quote ...

Linda, I was asking this question in another thread, but this looks more appropriate. If I understand what you said, the SHIPPING_MAX_WEIGHT is the CAPACITY of the Small/Medium box. Anything greater than that is considered Large box. (It is NOT the maximum allowed by the shipper, e.g. 70 lbs for USPS)

If that's the case, according to the logic of the calculation in includes/classes/shipping.php, you will NEVER use a Large box because when the actual product weight exceeds the SHIPPING_MAX_WEIGHT, the order is split into MULTIPLE boxes (presumably Small/Medium).

Seems to me that we need to make the SHIPPING_MAX_WEIGHT equal to the "allowable" maximum and add ANOTHER configuration term, the capacity of the Small/Medium boxes. Then the logic of the calculation would be:
1. IF actual_weight >= SHIPPING_MAX_WEIGHT, split shipment
2. IF actual_weight (per box) >= SMALL_BOX_CAPACITY, use Large box, else use Small/Medium box.
3. Compute appropriate tare weight additions.