Multiple Item Order Calculator
Fairly allocate a shared lump-sum shipping charge and sales tax across multiple items in a combined order to determine true individual item costs.
Item 1 (Main Item)
Item 2 (Secondary Item)
Proportional Shipping Allocation Formula
Item Allocated Shipping = Shared Shipping × (Item Subtotal / Total Subtotal); Fully Loaded Item Cost = Item Subtotal + Allocated Shipping + Allocated Tax- Proportional Weighting: Distributes flat shipping fees based on each product's economic share of the overall cart.
- Delivered Cost: True acquisition cost of each individual item delivered to your door.
Step-by-Step Worked Example
Calculation Steps:
How to Use This Calculator
Assumptions & Limitations
- Allocates shared postage proportionally based on item dollar value.
Frequently Asked Questions
How do you fairly split shipping when placing a joint order with friends?
The fairest standard method is value-proportional allocation: each person pays shipping matching their percentage of the total order value, preventing someone buying a $10 item from paying half of a $20 shipping fee.
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