> ## Documentation Index
> Fetch the complete documentation index at: https://docs.simplisent.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Order-Based Rates

> Shipping rates calculated from the products in each order, synced to your Shopify checkout

## What Are Order-Based Rates?

Order-based rates are shipping prices calculated from the products in a customer's cart, the parcel they ship in, and the destination. Instead of flat-rate or weight-only pricing, each order gets a rate based on what was actually ordered and where it's going.

SimpliSent calculates these rates using USPS pricing across all your parcel sizes, [USPS zones](/compliance/shipping-terms#zone), and weight tiers, then syncs them to your Shopify checkout. This works on any Shopify plan.

***

## How It Works

<Steps>
  <Step title="You Define Your Parcels">
    Tell SimpliSent what box sizes you ship with and which products go in each box.
  </Step>

  <Step title="SimpliSent Calculates Rates">
    SimpliSent determines the USPS zone for every US destination and calculates the exact shipping cost for every parcel-zone-weight combination.
  </Step>

  <Step title="Rates Sync to Shopify">
    With one click, rates are pushed to your Shopify store as a [delivery profile](/compliance/shipping-terms#delivery-profile).
  </Step>

  <Step title="Customers See the Right Price">
    At checkout, SimpliSent selects the correct rate based on what's in the cart and where it's going.
  </Step>
</Steps>

***

## What Customers See

At checkout, customers see a shipping option like:

> **Standard Shipping (3-5 business days)** - \$8.45

The price is based on:

* **Which parcel** their items fit in (from your product-to-parcel mapping)
* **Their location** (USPS zone from their ZIP code)
* **The package weight** (from the products in the cart)

***

## Key Concepts

| Term                    | Meaning                                                                                                                                                                      |
| ----------------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| **USPS Zones**          | USPS divides the country into zones (1-9) based on distance from your origin ZIP. Nearby zones cost less than cross-country zones. SimpliSent discovers zones automatically. |
| **Parcel Sizes**        | The box sizes you ship with. Each parcel's dimensions affect the rate.                                                                                                       |
| **Shipping Categories** | Groups of products that ship in the same parcel size. You assign products to categories during setup.                                                                        |
| **Weight Classes**      | SimpliSent calculates rates across 41 weight tiers (0-4 oz up to 65-70 lbs) to cover any product combination.                                                                |

***

## Getting Started

<CardGroup cols={2}>
  <Card title="Setup Guide" icon="wrench" href="/shipping-rates/setting-up-shipping-rates">
    Walk through the 3-step setup wizard.
  </Card>

  <Card title="Add to Shopify" icon="store" href="/shipping-rates/adding-rates-to-shopify">
    Sync rates to your Shopify checkout.
  </Card>

  <Card title="Manage Rates" icon="sliders" href="/shipping-rates/managing-shipping-rates">
    Regenerate, review, or remove rates.
  </Card>

  <Card title="Advanced Options" icon="gear" href="/shipping-rates/advanced-shipping-options">
    Fallback rates, price caps, and more.
  </Card>
</CardGroup>

<Note>
  Order-based rates require a connected Shopify store with products imported. See [Shopify Integration](/getting-started/shopify).
</Note>