Rate Types
Each shipping rule uses one rate type to calculate the price shown at checkout. Pick the type that fits how you want to charge for shipping.
All amounts are in your store’s currency, in cents. So $9.99 is entered as 999.
Flat rate
Section titled “Flat rate”A fixed price, no matter what’s in the cart.
Config: one amount field.
Example: You charge $8.00 for standard shipping on every order. Set the amount to 800. A cart with one item and a cart with ten items both get quoted $8.00.
Use this when you want simple, predictable shipping costs.
Weight-based
Section titled “Weight-based”A lookup table of weight brackets. Each bracket has a minimum weight, a maximum weight and a price.
Config: one or more brackets, each with minGrams, maxGrams and amount.
Example:
| Min (g) | Max (g) | Price |
|---|---|---|
| 0 | 500 | $5.00 |
| 501 | 1000 | $8.00 |
| 1001 | 5000 | $12.00 |
A 750g cart falls in the second bracket and gets quoted $8.00.
If the cart weight falls below the first bracket, the first bracket’s price applies. If it exceeds the last bracket, the last bracket’s price applies.
Per weight (per kg)
Section titled “Per weight (per kg)”A flat rate multiplied by the total cart weight in kilograms.
Config: one amountPerKg field.
Example: You charge $3.50 per kg. A 2.4kg cart costs 2.4 × $3.50 = $8.40.
This type scales linearly with weight, so heavier carts always cost more.
Per weight (tiered)
Section titled “Per weight (tiered)”A two-tier weight price. The first kilogram costs one amount, every additional kilogram (or part thereof) costs another.
Config: firstKgAmount and additionalKgAmount.
Example: First kg costs $6.00, additional kg costs $2.00.
- 0.8kg cart: $6.00 (fits within first kg)
- 2.1kg cart: $6.00 + (2 additional kg × $2.00) = $10.00
Note that additional kilograms are rounded up. A 2.1kg cart has 1.1kg beyond the first kg, which rounds up to 2 additional kg.
Per item (tiered)
Section titled “Per item (tiered)”A two-tier price based on item count. The first item costs one amount, every additional item costs another.
Config: firstItemAmount and additionalItemAmount.
Example: First item costs $5.00, each additional item costs $1.50.
- 1 item: $5.00
- 4 items: $5.00 + (3 × $1.50) = $9.50
This works well for stores shipping small individual products where each extra item adds a modest handling cost.
Percentage
Section titled “Percentage”A percentage of the cart’s total price.
Config: one percent field.
Example: You charge 8% of the cart total for freight. A $150.00 cart gets a shipping quote of $12.00.
If the cart total is zero, the rate is also zero.
Always returns $0.00. No configuration required.
Use this to offer free shipping on specific rules, like “free shipping for orders over $100” combined with a condition on cart total.
Summary
Section titled “Summary”| Rate type | Charges based on | Best for |
|---|---|---|
| Flat rate | Nothing, fixed price | Simple stores with one shipping price |
| Weight-based | Weight brackets | Products with wide weight variation |
| Per weight | Weight in kg | Linear weight pricing |
| Per weight (tiered) | First kg + additional kg | Courier-style pricing |
| Per item (tiered) | First item + additional items | Per-unit handling costs |
| Percentage | Cart total | Freight charged as a percentage |
| Free | Nothing, always $0 | Free shipping promotions |