A shelf's 99 lb load limit tells buyers how much it can hold, not how much it weighs. Yet a supplier file with one Weight column can send a load rating into a product-weight filter or a shipping calculation. Catalog and ecommerce teams need to identify what each number describes before using it in product pages, comparisons or feeds. Otherwise, buyers may rule out a suitable item or misunderstand how much it can support.
Key takeaways
Keep the item's own weight, its packed weight and its stated load capacity in separate fields.
Preserve what a capacity applies to, such as each shelf, and any conditions attached to it. Do not invent a whole-unit rating by adding component ratings.
Map reviewed values to the destination's definitions. A shipping charge based on dimensional weight does not change the product's actual weight.
Identify what the supplier weighed
Start with the source heading and the exact product or offer. Product weight describes the item itself. Packed weight describes the item with the packaging covered by that record. Weight capacity describes the load the manufacturer says the product or a named part can support. The same unit can appear in all three, but the numbers answer different questions.
For example, suppose a supplier confirms that a chair weighs 18 lb, weighs 23 lb in its shipping carton and has a stated user-weight limit of 250 lb. A buyer comparing chairs by product weight needs 18 lb. The shipping team needs the packed measurement for its shipment setup. The capacity statement belongs in a separate field with the manufacturer's applicable conditions.
| Supplier fact | Catalog meaning | Do not use it as |
|---|---|---|
| 18 lb chair weight | Weight of the chair itself | Packed weight or user limit |
| 23 lb packed weight | Weight of the identified packed item | Product weight or capacity |
| 250 lb user-weight limit | Stated supported load for the chair | Weight of the chair |
If the file only says Weight: 23 lb, leave the meaning unresolved until the source establishes it. Record the original label, unit, product identifier and source reference. A plausible number is not enough to decide whether it includes packaging.
Keep load limits attached to their scope
IKEA's US BROR shelf for wall upright, article 005.704.20, illustrates the distinction. The offer contains two shelves. Its measurements list a maximum load of 99 lb per shelf, while the packaging section lists 17 lb 2 oz for the package. The page also says the recommended maximum applies to an evenly distributed load. Mapping both to Weight would hide what each number describes. IKEA BROR shelf
Retain the words that make a capacity meaningful: per shelf, per seat, for the complete unit, or another scope stated by the manufacturer. Keep loading and installation conditions alongside the value. If a comparison table drops per shelf, a buyer cannot tell whether it describes one surface or the whole storage system.
Do not multiply a per-shelf rating by the shelf count to create a whole-unit rating. A catalog editor has not established the capacity of the frame, mounting system or complete configuration by doing that arithmetic. Request a stated whole-unit limit if the destination needs one. Likewise, do not turn a general tested-for statement into an unrestricted safe-load promise.
The BROR combination page separately gives anchoring instructions. Preserve relevant manufacturer warnings and link to the instructions rather than letting a short capacity label stand in for them. This is a way to represent supplied specifications, not a determination that a product is suitable for a particular load or installation. IKEA BROR combination
Ask for missing product weight instead of estimating it
A packaging measurement does not establish the unpacked weight. Do not subtract an assumed carton allowance, copy a related model's weight or use the load capacity to fill the gap. Ask for the actual measurement for the item and configuration being sold.
Supplier labels such as Net weight and Gross weight still need context. Confirm what is included and how many items the record covers before mapping either one. A net weight for a set cannot automatically become the weight of one chair. Keep that quantity decision with the measurement so the next import does not silently change its basis.
Convert units only after the meaning is settled, and keep the original value available for review. Mixed pounds and ounces require arithmetic, not punctuation replacement: 17 lb 2 oz is 17.125 lb, not 17.2 lb. A correct conversion still does not turn packed weight into product weight.
For products with several cartons, retain each package's measurements and identity. The furniture product and package dimensions guide covers that packing structure. A sum of package weights may be useful to a shipping owner, but it does not supply the unpacked product weight or prove how a destination will rate the shipment.
Map the weight to the field the channel actually uses
Google Merchant Center's product_weight attribute uses the actual assembled product weight. When a listing contains multiple pieces, Google says to use the complete weight of those pieces. Keep this separate from shipping_weight, which supplies the weight used by weight-based shipping settings. Neither field is a load-capacity field. Google product measurements · Google shipping weight
A carrier invoice can introduce another weight value. FedEx explains that dimensional weight reflects the space a package occupies and that the charge uses dimensional or actual package weight, whichever is greater. That billing value should not overwrite the measured weight of the item or package in your catalog. FedEx dimensional weight guidance
For Google carrier-calculated shipping, its guidance asks for actual shipping weight and uses submitted package dimensions as well. Have the shipping owner verify the service and shipment setup rather than substituting a billable weight for an actual measurement. A clean attribute mapping alone does not confirm a shipping quote. Google shipping weight guidance
Check the buyer view as well as the stored number
Return to the chair example and try a product-weight filter for items under 20 lb. The 18 lb chair belongs in that result; copying its 23 lb packed weight could hide it. A separate capacity comparison should show the stated 250 lb user limit with its qualifications. Check that the visible labels explain which comparison the buyer is making.
Review a small sample from each supplier through the full handoff: source label, stored value, filter, comparison table, description and destination field. Include one item with a missing unpacked weight and one with a capacity stated per component. The missing value should remain unresolved, and the component rating should retain its scope.
Then test a packaging-only change. If the chair's packed weight changes but the chair itself does not, the product-weight filter and user-limit statement should remain unchanged. Treat unexpected changes as a mapping problem to resolve before reusing the rule across the catalog. These are recommended review checks, not a substitute for manufacturer specifications.
Frequently asked questions
What is the difference between product weight and weight capacity?
Product weight is how much the item itself weighs. Weight capacity is the stated load it can support, subject to the manufacturer's scope and conditions. Store them separately so a buyer's lightweight-product filter does not use a load rating.
Can shipping weight fill a missing product weight?
No, unless the source explicitly establishes that the value also represents the item without packaging. Do not estimate packaging weight and subtract it. Google asks for actual assembled weight in product_weight, so an unresolved packed measurement is not a substitute. Google product measurements
Can per shelf capacities be added into one total?
Do not publish that total as a manufacturer rating unless the manufacturer establishes it for the complete configuration. Keep each stated per-shelf limit and its conditions. A sum does not establish the limit of the frame or mounting system.
Is dimensional weight the same as actual weight?
No. Dimensional weight is a carrier calculation based on package size. FedEx compares it with actual package weight for billing. Keep the calculated billing basis separate from measured product and packed weights. FedEx dimensional weight guidance
Should net and gross weight map automatically?
Only after you confirm the supplier's definitions and quantity basis. Keep what the measurement includes, the item or set it covers, its unit and its source. Do not treat an unexplained net or gross label as enough evidence for an item-level product-weight field.
Where does weight capacity belong in a Google feed?
Do not put it in product_weight or shipping_weight. Preserve capacity as a separately labeled specification in your catalog, then check the supported field and rules for the destination. Google's two weight attributes describe product measurements and shipping calculations, respectively. Google product measurements · Google shipping weight
How this gets done in Merchkit
Merchkit's documented source and attribute workflows can reduce repeated copying from supplier files. Bring a small weight sample to a demo and evaluate whether the configured output preserves the distinctions your catalog needs.
Keep the two source records together. Attach the exact product specification and packing reference to the relevant item so enrichment can use that material without a fresh copy-and-paste exercise for each field. Check that the source covers the offer you sell. How Sources Work
Make the fields specific. Use custom attributes and instructions for product weight, packed weight, capacity scope and conditions. Reuse the definitions across a supplier batch while retaining the original labels for review. Test your field definitions against the sample before reusing them. Creating Custom Attributes
Prepare a small batch before scaling. Merchkit documents generation for selected products and an empty-only option. Evaluate it with known examples and missing values first; filling an empty field does not verify the answer or repair an existing mistake. Running Your First Enrichment
Review meaning before reuse. Inspect proposed values and their rationales against the source, then check buyer-facing labels and the destination mapping. Keep unsupported capacities unresolved. Human acceptance and the shipping handoff remain team responsibilities. Reviewing AI-Generated Content
Book a Merchkit demo with a supplier sheet that mixes product weight, packed weight and capacity, and walk through the review before expanding the workflow.
