Why the number matters more than it looks
- Carrier-calculated rates are computed from weight. A 0 kg variant quotes the cheapest bracket, and the gap comes out of your margin on every sale, forever.
- Duty and customs estimates use weight too, so a missing or wrong weight makes an international quote unreliable.
- It is one field, set once per variant, that touches every order that product is ever part of.
Six ways to get an accurate weight with things you already own
- Ask the supplier first. Manufacturers weigh their goods for their own shipping. For dropship or Shopify Collective catalogs, the spec sheet is the fastest and most accurate source. Get it per product line, not per SKU.
- Use a kitchen scale for small items. Anything under a few kilos, a basic kitchen scale reads in grams, which is the unit Shopify wants anyway.
- Use a bathroom scale for heavy items. Weigh yourself, then weigh yourself holding the item, and subtract. Rough, but fine for anything heavy enough that a small error does not change the shipping bracket.
- Weigh a batch and divide. For light items where one unit is below your scale's resolution, weigh ten and divide by ten. The error averages out.
- Weigh the packed parcel, not the bare product. Shipping weight includes the box, the filler, and the label. Pack one real sample per product family and weigh that, so the rate at checkout matches what you actually hand the carrier.
- Fall back to a known reference for tiny things. A stack of coins or a standard sheet of paper has a published weight you can total up. It is a last resort, but a considered estimate beats a zero every time.
Do not forget dimensional weight
Large, light items like a pillow or a lampshade are billed on the space they take up, not their mass. Carriers charge whichever is greater, actual or dimensional. Measure the packed box and record the dimensions on the variant too, or a weight-only rate will still undercharge you.
Where it goes in Shopify
Weight lives on the variant, in the Shipping section of the product, not on the product as a whole. Two sizes of the same item can weigh different amounts, so set it on each variant. If you have a lot of them, the bulk editor has a weight column.
Check your work
Once you have set weights, run the free catalog completeness check to see which variants are still at zero. The count is your to-do list. When it reaches zero, every rate your store quotes is one you can actually honour.
Common questions
Do I need a shipping scale to sell on Shopify?
No. You can get an accurate enough weight from your supplier's spec sheet, a kitchen or bathroom scale you already own, or by weighing a batch and dividing. What matters is that each variant's weight is close to the real packed weight, not that it came from a shipping scale.
What happens if a product's weight is zero in Shopify?
A zero weight makes carrier-calculated rates quote the cheapest bracket, so you absorb the difference on every order, and it makes international duty estimates unreliable.
Where do I set product weight in Shopify?
On each variant, in the Shipping section of the product, not on the product as a whole, since sizes can weigh different amounts. For many products at once, use the bulk editor's weight column.
Free · Beta · Read-only
- Free to use, in beta.
- The free check reads only your public storefront. No access to your store required.
- The connected audit uses Shopify's official read-only permissions. Storecheck can look, never write, place orders, or change anything.