SELLERSTACK PARCEL TOOL
UK Parcel Size
Checker
Check whether your packed parcel fits the size and weight limits for popular UK delivery services before you buy postage.
Parcel Size Checker
Check whether your packed parcel fits the size and weight limits for popular UK delivery services.
Select the carrier you plan to use.
Choose the parcel format or delivery service.
Include all packaging and protective materials.
Choose a carrier and service, then enter your packed parcel dimensions and weight.
Enter your parcel measurements.
The second-longest side will be checked here.
The shortest side will be checked here.
The packaged weight will be checked here.
This service uses a combined measurement limit.
Example: a 60 × 40 × 30cm parcel has a combined measurement of 60 + 80 + 60 = 200cm.
What Does the UK Parcel Size Checker Do?
The SellerStack UK Parcel Size Checker helps you check whether a fully packed parcel fits the size and weight limits of the selected delivery service before you buy postage.
Enter the outside dimensions in any order, add the finished parcel weight and select the carrier and service you intend to use.
The checker automatically identifies the longest side, compares the parcel with the selected service limits and calculates length + girth where that type of measurement is required.
Reviewed: October 2026
Carrier parcel limits, accepted formats, drop-off restrictions and service rules can change.
SellerStack periodically reviews the assumptions used by this checker, but you should confirm the current requirements for your chosen service before sending valuable or unusual items.
How to Use the UK Parcel Size Checker
Check the parcel only after the item has been completely prepared for dispatch.
1. Select the Delivery Carrier
Choose the carrier you plan to use so the checker can show the available parcel services and formats.
2. Choose the Parcel Service
Select the service or parcel category you are considering. Different services can use different maximum dimensions and weight limits.
3. Measure the Finished Parcel
Measure all three outside dimensions of the box, mailing bag or other finished package in centimetres.
4. Weigh the Finished Parcel
Include the product, outer packaging, padding, labels and other materials that will actually be sent.
5. Check the Result
The tool compares the measurements and weight with the selected service and highlights anything that exceeds the configured limits.
6. Verify Before Buying Postage
If the parcel is close to a maximum limit, check your measurements again and confirm the current carrier rules before purchasing the label.
How to Measure a Parcel Correctly
Carrier limits apply to the package that enters the delivery network, not to the product before it is packed.
Longest Side
The checker automatically treats the longest of the three dimensions you enter as the parcel length.
Second-Longest Side
The second-longest measurement becomes the width for the purpose of checking the parcel.
Shortest Side
The shortest measurement is treated as the height or thickness.
Entire Packed Parcel
Weigh the product together with the box, mailing bag, padding and other packing materials.
You can enter the three dimensions in any order
You do not need to work out which side is technically the length before using the checker. Enter all three measurements and SellerStack identifies the longest, second-longest and shortest sides automatically.
Measure After Packaging — Not Before
Packaging can materially change both the dimensions and weight of an order.
This is particularly important for items that need:
- Bubble wrap or protective padding
- A double-wall cardboard box
- Corner protection
- Additional void fill
- A mailing bag around another package
- Reinforcement for fragile products
A product measuring 44cm long does not automatically fit a service with a 45cm maximum length.
Once the product is placed inside a box and protected for shipping, the finished parcel could exceed the limit.
What Is Length + Girth?
Some parcel services use a combined measurement rather than relying only on individual length, width and height limits.
Length + Girth Formula
Longest Side + (2 × Width) + (2 × Height)
A finished parcel measures:
- Length: 60cm
- Width: 40cm
- Height: 30cm
Length + girth is:
60 + (2 × 40) + (2 × 30) = 200cm
A lightweight parcel can still be too large for a service because the combined measurement exceeds its permitted limit.
That is why checking weight alone is not enough.
UK Courier Parcel Limits Are Not All the Same
Different carriers—and different services from the same carrier—can classify the exact same package differently.
The figures below show why you should select the actual service you intend to use rather than assuming one universal UK parcel limit.
| Example | Current Published Limit | What It Shows |
|---|---|---|
| Royal Mail Small Parcel | Up to 45 × 35 × 16cm and 2kg | Individual dimensions and weight both matter. |
| Royal Mail Medium Parcel | Up to 61 × 46 × 46cm and 20kg | Moving into another parcel category can allow a much larger and heavier package. |
| Evri ParcelShop / Courier | Up to 15kg, maximum length 120cm and combined length + girth below 245cm | Some couriers use a combined measurement rule. |
| Evri Locker | Separate locker-size dimensions apply | The handover method can change the accepted parcel size. |
These examples are provided to explain how parcel limits differ. They should not replace the live rules for the exact service you intend to purchase.
Carrier services, limits and handover options can change.
Parcel Size Limit vs Parcel Weight Limit
A parcel normally needs to satisfy every relevant requirement for the selected service.
Size Check
The parcel must fit within the permitted dimensions and any applicable combined measurement rule.
Weight Check
The complete packaged weight must also remain within the maximum allowance for the selected service.
Passing one limit does not cancel out failing another
A parcel can be light enough but physically too large, or small enough but too heavy. Both situations can make the selected service unsuitable.
What Should You Do If the Parcel Exceeds the Limit?
A failed result does not necessarily mean the item cannot be shipped. It means the parcel does not fit the selected service using the measurements entered.
1. Check the Measurements Again
Confirm that the outside dimensions and packaged weight have been entered correctly.
2. Review the Packaging
See whether unnecessary empty space can be removed without compromising protection.
3. Try Another Service
Another parcel category or carrier may accept larger or heavier packages.
4. Compare the New Shipping Cost
A service that accepts the parcel may cost more, so recalculate the effect on your fulfilment cost and profit.
Your Parcel Fits — Now Compare Shipping Costs
Compare Royal Mail, Evri, DPD and another courier using your latest quotes, packaging costs and delivery requirements to find the strongest option for the shipment.
Why Parcel Size Can Change Your Shipping Cost
Moving outside a parcel category can change the delivery services available to you and potentially increase the amount you need to pay.
That means parcel sizing is not simply a packaging question. It can affect:
- Which courier services are available
- The postage price you pay
- The amount of postage you need to charge the buyer
- Your final profit on the order
- Whether free shipping remains commercially viable
When two packaging options protect the product equally well, the smaller finished parcel can sometimes open up a cheaper shipping category.
The goal is not to use the smallest package possible at any cost. It is to avoid unnecessary size while still protecting the item properly.
Worked Example: Checking a Packed Parcel
Imagine you are dispatching a boxed games console.
| Measurement | Finished Parcel |
|---|---|
| Length | 42cm |
| Width | 28cm |
| Height | 14cm |
| Weight | 1.8kg |
The checker identifies 42cm as the longest side and calculates:
42 + (2 × 28) + (2 × 14) = 126cm length + girth
It then compares those measurements and the 1.8kg packaged weight with the limits of the selected service and shows whether the parcel fits.
Common Parcel Sizing Mistakes
1. Measuring the Product Instead of the Parcel
Carrier limits apply to the finished shipment after packaging has been added.
2. Forgetting Packaging Weight
Boxes, protective materials and other packaging all contribute to the final weight.
3. Rounding Measurements Down
If a parcel measures slightly over a limit, recording the lower figure does not make the physical parcel smaller.
4. Assuming Every Courier Uses the Same Rules
Size limits and measurement methods vary between carriers, services and handover options.
5. Ignoring Length + Girth
A parcel may fit individual-looking dimensions yet still fail a combined measurement limit.
6. Automatically Choosing a Larger Service
Paying for a larger category when the finished parcel already fits a smaller suitable service can create unnecessary fulfilment cost.
7. Compressing Packaging Too Aggressively
Saving a few centimetres is not worthwhile if it leaves the product inadequately protected in transit.
8. Not Rechecking After Repacking
If you change the box, padding or outer packaging, measure and weigh the finished parcel again.
Parcel Check Before You Buy Postage
- Is the item completely packed?
- Have I measured the outside of the finished parcel?
- Have I weighed the parcel with all packaging included?
- Have I selected the correct carrier?
- Have I selected the exact service or parcel format?
- Does the longest side fit the service limit?
- Do the other dimensions fit?
- Does the packaged weight fit?
- Does any applicable length + girth limit pass?
- Is the packaging still sufficient to protect the item?
- Have I checked the carrier’s current rules?
Thermal Label Printer for Regular Dispatch
If you ship orders regularly, a 4 × 6-inch thermal label printer can speed up dispatch and print courier labels without ink or toner cartridges.
UK Parcel Size Checker FAQs
Why should I measure the parcel after packing?
Courier limits apply to the finished parcel entering the delivery network. Boxes, mailing bags, padding and other protective materials can increase both dimensions and weight.
Can I enter length, width and height in any order?
Yes. SellerStack automatically identifies the longest, second-longest and shortest measurements entered before comparing them with the selected service.
What is length + girth?
It is a combined parcel measurement used by some delivery services. SellerStack calculates it as the longest side plus twice the width plus twice the height.
Does the Parcel Size Checker calculate postage prices?
No. This tool checks parcel size and weight eligibility. Use the SellerStack UK Shipping Cost Comparison Calculator when you want to compare current courier quotes and complete fulfilment costs.
Which delivery carriers are included?
The checker currently includes Royal Mail, Evri and Yodel by InPost service options configured in the tool. Available services may be updated as carrier rules change.
What happens if my parcel is too large?
The checker highlights the limits that have been exceeded. You can then review the packaging, select another parcel category or compare another delivery service.
What happens if my parcel is too heavy?
A parcel that exceeds the selected service’s weight allowance does not qualify even if all three dimensions fit. Select another suitable service or carrier.
Should I round my parcel measurements?
Measure accurately and avoid rounding dimensions down to make a parcel appear to fit. If you are close to a service limit, recheck the parcel before purchasing postage.
Does the checker confirm whether my item is allowed by the courier?
No. Passing the size and weight check does not confirm that the contents meet the carrier’s prohibited, restricted or packaging rules.
Does the checker include compensation cover?
No. This tool focuses on parcel dimensions and weight. Compensation, tracking, delivery speed and other service considerations should be checked separately.
Can I use this for eBay, Vinted, Amazon, Etsy or Shopify orders?
Yes. Parcel size is independent of the selling platform. The checker can be used whenever you are preparing a physical parcel for a supported carrier service.
Is the SellerStack Parcel Size Checker free?
Yes. The UK Parcel Size Checker and SellerStack’s other seller calculators are free to use.
Measure the Finished Parcel Before You Pay for Postage
Parcel size can determine which delivery services are available and how much fulfilment ultimately costs.
Measure and weigh the finished package, check it against the service you actually intend to use and avoid automatically paying for a larger parcel category when it is not required.
Once the parcel fits, compare the available shipping options using current quotes before purchasing the label.
Use the Checker as a Shipping Planning Tool
The SellerStack UK Parcel Size Checker provides a general size-and-weight eligibility check based on the service rules configured in the tool.
It does not confirm postage price, prohibited or restricted items, compensation eligibility, destination restrictions, marketplace label requirements or every carrier-specific condition.
Parcel limits, service availability, handover methods and carrier rules can change. Always verify the current requirements of the selected service before dispatching an important or valuable parcel.
SellerStack is independent and is not affiliated with or endorsed by Royal Mail, Evri or Yodel by InPost.
Turn the Parcel Check Into a Better Shipping Decision
Continue with SellerStack’s free shipping tools and practical guides for parcel sizing, courier comparison, packaging and fulfilment decisions.
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