4 questions regarding Weight attribute product

Question

While learning "How to Add a NEW product in Magento 1.9", I came across few fields (attributes) and totally confused and 3 doubts barricaded me to move further...

1. What is the use of weight field in General tab of product creation form, I gone through the Megento user guide where it mentioned for weight attribute - "Enter the Weight of the product, which is used to calculate shipping".

2. I referred many examples and found some number are enter in weight field for example - 0.3000 or 1, I want to know which measurement unit is used for this attribute.

3. How I will calculate the final cost of the product, for example - Green beans with different weight in drop down 100g, 150g, 200g, 250g, 300g, 500g (Yes I added this drop down by using custom option tab). Also Qty is there suppose buyer need 1.5Kg then they may select 500g from weight and enter 3 in Qty text field. Price of item is 10.75 for 100g. And this non taxable good. So the Total price of the item is 1500g*10.75 = 161.25, Now how can I perform this calculation or where I need to setup this formula.

4. If in some product price varies based on weight, then shall I enter the price in custom Option Tab in front of respective weight like this -

   Title* Price* Price Type*
   100 g           Fixed
   150 g           Fixed
   200 g           Fixed
   250 g           Fixed
   300 g   9.00    Fixed
   500 g   8.50    Fixed

Suggestion / Guidance/ Advice any thing will help me to move on step. For reference I attached 1 image of my store

Answer 1

1. What is the use of weight field in General tab of product creation form?

Answer: You are right that weight is used to calculate the shipping price of the product. It does not have to do anything for price calculation of the product (unless weight attribute has been used for catalog price rule).

2. Answer: The measurement unit is whatever is being used for shipping. You can sometimes control it in System > Configuration > Shipping Methods.

3. How I will calculate the final cost of the product?

Answer: Product weight has nothing to do with cost or price of the product. For the scenario like Green beans with different weight in drop down 100g, 150g, 200g, 250g, 300g, 500g; you can create simple products with different weight and different names like Green beans 100g etc. and then associate these simple products into one configurable product.

This will create a drop-down in the way how you want.

4. Answer: By simple and configurable products way, you can manage different prices for different variations.

Note: By configurable products, you can manage inventory of different variations of products also.

Please let me know if I was able to answer your questions.

Answer 2

The weight attribute does not do anything by itself. You will need to write your own module to incorporate this into any kind of pricing.

What you probably want are required custom options to adjust prices depending on the weight option. A configurable product works for this, too, but it doesn't use simple products' prices, so you'll have to put price adjustments anyway, and it'll just make it more complicated. Again, it depends on your business needs.

Update:

Create a simple product with custom options. See this image below.

Note:

1. Attribute weight, as I explained above, has nothing to do with pricing.
2. You'll have to write some JavaScript that updates the price on the frontend.