FlexiFeesWeight-based fees (per kg)
Last updated: July 18, 2026
A weight-based fee multiplies your rate by weight in kilograms: the whole cart's weight for a cart fee, or the matching items' weight for a per-product fee. Variant weights in grams, ounces, and pounds are converted automatically, and quantities are respected.
Weight cart fee: rate × total cart weight
Best for charges that follow the shipment as a whole. The classic recipe is the heavy order surcharge: add a cart weight condition (for example, at least 20 kg) so normal orders pay nothing, and heavy orders pay your per-kilogram rate.
Weight per-product fee: rate × matching items' weight
Best when only some products carry the charge. Your product conditions select the items; each contributes its unit weight times quantity. Real examples:
- France's furniture eco-participation, which scales with product weight.
- Bulky-goods handling on the Furniture collection only, while small accessories ship free of surcharge.
Details worth knowing
- Units are handled for you. Whether variants are weighed in grams, ounces, or pounds, everything is normalized to kilograms before the rate applies.
- Products without a weight add zero. Fill in variant weights for the products the fee should cover.
- Caps available. Weight fees accept optional minimum and maximum amounts, like all calculated fees.
- Fee lines carry no weight themselves, so the fee never inflates its own calculation or your shipping rates.