Free online shipping tools for UK sellers. Resize a label, calculate dimensional weight, check a Royal Mail format, test a letterbox, all before you print.
Everything here runs free in your browser with no sign-up. The label resizer reformats any courier label to 4x6, A4 or sticker sheets. The dimensional weight calculator works as a parcel size calculator for DHL, FedEx and UPS so you know the billable weight before you pay. The Royal Mail format checker tells you whether your item is a Letter, Large Letter, Small Parcel or Medium Parcel, and the letterbox checker tells you if it will fit through the slot. Below they are grouped by what you need: calculators and checkers first, then label resizing by courier and by selling platform.
Resize shipping label PDFs to 4×6, A4 or half-page stickers. Works with every UK courier.
Open toolWork out billable weight for Royal Mail, Evri, DPD, Parcelforce, DHL, FedEx and UPS before you pay.
Open toolCheck whether your parcel falls under Letter, Large Letter, Small Parcel or Medium Parcel pricing.
Open toolStandard UK letterbox is 250 × 38 mm. Check if your package fits before posting.
Open toolFill in and print a CN22 international customs declaration. Required for parcels outside the UK.
Open tool