Weight shipping rates not working as intended?

[Surrenic]

It is extremely confusing.
I have 2 rates one is for envelop shipping (stickers) and the other for packages (clothing).
I've set both rates on weight. Stickers weight are set to 0.01 KG and clothing to 0.5 to test.

The rates go as follows:

€2,95 based on weight 0kg to 0.49kg.
€5,95 based on weight 0.50 to unlimited. 
When at checkout it picks the 5,95 no matter what. Even for one sticker or 10.

When testing it with prices
€2,95 based on price €0 to €15,-

€5,95 based on price above €15,- 
Does work. So something is wrong in the weight. Checked all products have the correct weight added and they do. I'm completely lost, don't want to put it on max €15 in case I get new and cheaper products.

Anyone have an idea? I don't wat to install an APP or work on flexible ratings atm. 

[goldi07]

Hello @Surrenic 

Shopify's weight-based shipping can be weirdly finicky, especially when products have super small weights like stickers. Let's break down what’s likely going wrong and how to fix it—without using apps or switching to price-based rates.

Problem Breakdown:
You set:

. €2.95 for 0 kg to 0.49 kg

. €5.95 for 0.5 kg to unlimited

Your sticker is 0.01 kg, so it should trigger the €2.95 rate… but it doesn't.

Common Issues That Cause This:
1.Packaging weight (a.k.a. “default package”) adds extra grams/kilos at checkout.

2.Cart weight rounding up to 0.5 kg.

3.Stickers marked as “Requires shipping” = No — Shopify won’t include them in the shipping calc.

4.Products have variants and you forgot to add weight to each variant.

5.Fulfillment settings or shipping profiles conflict (especially if you’re using multiple shipping profiles).

Fix Checklist (Step-by-Step):
1.Check Packaging Defaults
Go to Settings > Shipping and delivery > Packages

. If your default box/envelope adds 0.5kg, your sticker will always fall into the €5.95 bracket.

. Try removing or minimizing the package weight for testing.

2.Ensure Stickers are set as “Requires Shipping”

. Edit product → Scroll to Shipping section → Confirm “Requires shipping” is checked.

. If not checked, Shopify ignores them in weight-based rates.

3.Check Variants

. If stickers have variants, each variant must have a weight set, not just the parent product.

4.Verify Single Shipping Profile

. Go to Settings > Shipping and delivery > Shipping profiles

. If stickers and clothing are in different shipping profiles, they’ll combine shipping rates in a way you can’t control.

. Best practice: Keep them in the same profile and use weight tiers like you are now.

5.Test Using Draft Order

. Create a draft order with one sticker and see what Shopify calculates for shipping.

. Good way to isolate if something’s adding unexpected weight.

Bonus Tip: Use Grams for Fine Control
Shopify handles grams more accurately than small KG values.

So instead of:

. 0.01 kg → use 10 grams

. 0.5 kg → use 500 grams

And set your rates as:

. €2.95 → 0g to 499g

. €5.95 → 500g and up

This often clears up weird rounding issues.

TL;DR Fix Plan:
1.Use grams instead of decimals in kg

2.Check if any default packaging weight is pushing totals up

3.Ensure "Requires shipping" is ticked

4.Keep all products in one shipping profile

5.Double check variant weights

Thank you 😊