Royal Mail label size checker for 6x4 thermal printing
Check whether your Royal Mail or Click & Drop label PDF is ready for a 6x4 thermal printer, or whether it needs a page-size, scaling or crop fix before you waste another label.
Quick answer
- 6x4 inches, 4x6 inches and 100x150mm are the safest thermal-printer targets.
- A4 PDFs are fine for desktop printers, but usually need cropping before thermal printing.
- Actual Size / 100% scale is safer than fit to page for barcode quality.
- If edges are cut off, check the paper preset and calibrate the thermal printer.
Interactive checker
Check the PDF size before you print
This does not upload or store your label. Choose what you see in your PDF properties or print preview and the checker gives the safest next step.
Result
Likely ready for a Royal Mail 6x4 thermal print
Your selected size is a sensible target for Royal Mail labels on a thermal printer. The main risk is accidental scaling in the print dialog.
Width
101.6mm
Height
152.4mm
Width in inches
4.00in
Height in inches
6.00in
Recommended next step
Print one test label first, then check the border, address block and barcode with the checklist below.
Royal Mail label sizes for thermal printers
For thermal printers, aim for 6x4 inches, 4x6 inches or 100x150mm. Those sizes match the label rolls used by many Zebra, Dymo, Brother, MUNBYN and Rollo-style shipping label printers.
A6 is close and may work if the exported PDF and printer driver agree on the same preset. A4 is different. It is designed for a desktop printer page, so a 6x4 thermal printer usually needs the label cropped or exported first.
Click & Drop print settings to check
In Royal Mail Click & Drop or your PDF viewer, check the final PDF page size before printing. If the label preview fills a 6x4 page cleanly, print at Actual Size or 100% scale.
- Paper size: 6x4, 4x6, 100x150mm or the closest matching preset.
- Scale: Actual Size or 100%.
- Orientation: portrait unless the preview is clearly rotated.
- Darkness: increase one step if barcode lines look faint.
Why Royal Mail labels print too small
A label usually prints too small when the print dialog tries to fit a PDF onto a different page size. Browser print dialogs can also shrink the page without making the warning obvious.
If the address block and barcode look tiny, reopen the PDF in a dedicated viewer, choose the correct 6x4 or 100x150mm paper preset, then turn off fit to page and shrink oversized pages.
When LabelChop helps with Royal Mail PDFs
LabelChop is for sellers who keep receiving awkward shipping label PDFs from carrier, marketplace or ecommerce workflows and want the crop-and-print step automated. It watches a folder, detects shipping-label PDFs, crops them to 4x6 / 100x150mm and prints or saves them for the thermal printer.
LabelChop is not an official Royal Mail or Click & Drop integration. It helps with the PDF workflow after you have the label file. For one-off A4 files, try the free A4 to 4x6 shipping label converter first.
FAQ
What size are Royal Mail labels for thermal printers?
For thermal printers, the common target is 6x4 inches, also written as 4x6, or the close metric size 100x150mm. A6 can work in some workflows if the PDF and printer preset match.
Can Royal Mail Click & Drop print 6x4 labels?
Many Click & Drop workflows can produce labels suitable for 6x4 thermal printers, but exported PDFs and print dialogs can still cause scaling or page-size mistakes. Always check the PDF size and print at 100%.
Why is my Royal Mail label printing too small?
The usual cause is fit to page, shrink to printable area, a mismatched paper preset, or sending an A4 PDF to a 6x4 printer without cropping the label first.
Is LabelChop an official Royal Mail integration?
No. LabelChop helps with shipping-label PDFs from carrier and marketplace workflows. It is not an official Royal Mail or Click & Drop integration.