Charge tiered shipping rates by order total — multiple shipping options per geo zone, each with its own price tiers. Also supports billing by weight or cart item count.

OpenCart's built-in flat-rate shipping gives you one price per zone. Total-Based Flat Shipping Rates – Slabs gives you everything a real store needs:

Tiered pricing — different rates for a $20 order vs a $500 order
Multiple service tiers per zone — Standard, Two Day, Next Day, etc., each shown to the customer as a separate selectable option
Three calculation modes — pick whether tiers are indexed by order subtotal, total weight, or total items in cart


Configure as many shipping options per geo zone as you want, with as many tiers per option as you need. The customer self-selects their preferred speed at checkout.

Example rates slab:

------------------------------------------------------------------------------
Order Subtotal | Standard | Two Day | Next Day
------------------------------------------------------------------------------
$0 - $25 | $4.95 | $18.95 | $39.95
$25 - $50 | $8.95 | $20.95 | $44.95
$50 - $100 | $10.95 | $24.95 | $49.95
$100 - $500 | $15.95 | $29.95 | $59.95
------------------------------------------------------------------------------

Canada:
------------------------------------------------------------------------------
Order Subtotal | Standard | Two Day | Next Day
------------------------------------------------------------------------------
$0 - $25 | $7.95 | $20.95 | $39.95
$25 - $50 | $9.95 | $22.95 | $44.95
$50 - $100 | $12.95 | $26.95 | $49.95
$100 - $500 | $15.95 | $32.95 | $59.95
------------------------------------------------------------------------------


Key features
✅ Multiple shipping options per geo zone — Standard, Express, Next Day, anything else
✅ Tiered pricing — different rate for each subtotal / weight / quantity band
✅ Three calculation modes — order subtotal, total items, or total weight
✅ Unlimited geo zones — works with OpenCart's built-in Geo Zone system
✅ Unlimited tiers per shipping option — no cap on rate brackets
✅ Tax-class aware — apply a tax class to the shipping cost if needed
✅ Validated input — clear error messages on malformed rates; no silent $0 quotes at checkout
✅ AJAX admin save — no page reloads while you configure
✅ Bootstrap 5 admin UI — matches OpenCart 4's native look

Perfect for
- US stores running domestic + international zones with multiple delivery speeds
- B2B stores charging different per-item rates as cart size grows
- Heavy-goods retailers using weight-based pricing with tiered breaks
- Any merchant who has outgrown OpenCart's single-rate built-in flat shipping[/list]