Before You Start
Make sure you have:- A connected Shopify store (Connect Shopify)
- Products imported from your store (products import automatically once Shopify is connected)
- Product weights set in Shopify for every product (required for rate calculations)
Step 1: Add Parcel Sizes
Enter every box size you use to ship orders. For each parcel, provide:- Name - a recognizable label (e.g., “Small Box”, “12x9x4 Mailer”)
- Dimensions - Length x Width x Height in inches
Step 2: Categorize Products
Use the drag-and-drop interface to assign your Shopify products to parcel categories.- Left panel - unassigned products (from Shopify), grouped by weight
- Right panel - drop zones for each parcel category
Combo-Only Parcels
If a parcel size is only used when shipping multiple items together (never for a single product), check the Combo only box on that category.Step 3: Set Category Limits
For each category, set the Max Items - the maximum number of products that fit in that parcel size. This controls bin-packing at checkout when a customer orders multiple items.| Category | Parcel | Max Items |
|---|---|---|
| Small Items | 6x4x3 Box | 3 |
| Medium Items | 12x9x4 Mailer | 2 |
| Large Items | 18x14x8 Box | 1 |
Calculate Rates
After completing all three steps, click Calculate Rates. SimpliSent will:- Discover USPS zones for every US destination from your origin ZIP
- Calculate the exact USPS cost for every parcel-zone-weight combination
- Save all calculated rates for syncing to Shopify
What’s Next
Once complete, review your rates and sync them to Shopify.Add Rates to Shopify
Push your calculated rates to your Shopify checkout.