Shipping Label Size Guide for Australian Couriers

Ordering the wrong label roll is one of the fastest ways to stall a packing bench. The roll arrives, it will not fit the printer spindle, or the print lands halfway across the gap between labels, and the parcels sit there while someone rings the supplier. Almost every one of those calls comes down to two numbers: the label size and the core size.

This guide covers the sizes Australian couriers use, what the alternative measurements mean, and how to match a roll to the printer sitting on your bench.

The standard size for Australian couriers

If you dispatch parcels in Australia, the size you need is almost certainly 102mm x 152mm, also listed as 100mm x 150mm.

Australia Post eParcel and MyPost Business, CouriersPlease, Sendle, Aramex, StarTrack, TNT, Direct Freight and DHL Express all generate labels in this format. Shipping platforms such as Shippit, Shiptheory and the major ecommerce plugins default to it as well. That consistency is the reason 4 x 6 inch rolls dominate warehouse shelves across the country.

Omni stocks this size as a 102mm x 152mm roll of 300 labels on a 40mm core, which suits most desktop printers. Browse the full thermal labels range to see the other roll counts and core options available.

Australia Post MyPost Business prints international labels on A4 paper only, so keep a supply of A4 sheet labels alongside your thermal rolls. eParcel and Parcel Send contract customers can print eligible international labels on A6 thermal stock instead.

Why you'll see 100mm x 150mm and 102mm x 152mm

These are the same label for practical purposes.

A 4 x 6 inch label converts to 101.6mm x 152.4mm. Some manufacturers round that down to 100mm x 150mm and some round it up to 102mm x 152mm, which is why two listings that look different will both feed correctly through a printer set to 4 x 6 inch. A two millimetre variation sits well inside the tolerance of a 104mm print head and the sensor gap on either side of the label.

What this means in practice: if your carrier asks for 100 x 150 and your supplier lists 102 x 152, you can order it. For higher volume benches, the same size is available as 1000 labels on a 76mm core for industrial units.

Other sizes worth knowing

102mm x 175mm for connotes and integrated labels

Longer rolls suit freight connotes and integrated documents that carry additional consignment detail below the barcode. Perforated stock helps here, because the operator can separate labels cleanly without a cutter. Omni's 102mm x 175mm perforated roll carries 900 labels on a 76mm core.

100mm x 206mm for Express Post

Express Post lodgement documents run longer than standard parcel labels. If your operation runs a mix of Express and standard services, most dispatch teams keep two printers loaded rather than swapping rolls all day.

Smaller formats for product and carton identification

Not every label on a parcel is the shipping label. Common supporting sizes include:

• 102mm x 50mm for high volume barcode and carton marking, available in 2740 labels per roll
• 105mm x 73mm for general product identification with a permanent adhesive
• 75mm x 51mm for inventory and shelf marking

Common warehouse label sizes

Other common warehouse label sizes include:

Core size decides whether the roll fits at all

Label dimensions tell you what prints. Core size tells you whether the roll physically mounts on the spindle, and it is the single most common reason a delivery gets sent back.

The 75mm and 76mm figures describe the same three-inch core, measured internally or externally depending on the manufacturer. Either will mount on a three-inch spindle. The 38mm and 40mm figures describe the 1.5-inch core used on many mid count desktop rolls, so check that your roll holder accepts it before ordering.

Larger cores carry more labels, which means fewer roll changes on a busy bench. A high-count roll can run most of a shift without interruption, but only if the printer takes it. Check the spindle before ordering bulk.

Direct thermal or thermal transfer

Size is only half of the decision. The print method determines how long the label stays readable.

A direct thermal label prints using a heat sensitive coating, with no ribbon required. It is the standard choice for courier labels because a parcel is scanned and delivered within days, well inside the window where the print stays sharp. Fewer consumables also mean lower running costs and less downtime.

Thermal transfer uses a ribbon to fuse pigment onto the label surface, producing a print that resists heat, sunlight, abrasion, and moisture for far longer. Choose this for freight held in yards, cold storage, export cartons or anything that will sit outdoors. Omni stocks 102mm x 175mm thermal transfer stock for these applications.

For most Australian ecommerce and 3PL dispatch, direct thermal is the correct default.

Using colour to sort dispatch

Coloured thermal labels do the same job as white stock, with the colour carrying the sorting logic instead of the text. Teams use them to flag priority freight, separate carriers on a shared bench, mark stock rotation or route parcels to the right outbound lane without reading a word.

Yellow is the common choice for high visibility work, and it comes in the same 102mm x 152mm format as Omni's white shipping labels, so nothing about your printer setup has to change. Omni carries it as 500 labels on a 25mm core for desktop printers and 1000 labels on a 76mm core for industrial units. Custom colours and sizes can be produced for larger operations.

How to check what you're currently running

Before reordering, take two measurements from the roll on the bench:

1. Label face. Measure width first, then length, in millimetres. Ignore the backing paper, which is usually a few millimetres wider.
2. Core. Measure the inside diameter of the cardboard tube. It will usually be close to 25mm, 40mm or 76mm.

Write both numbers on the purchase order. Those two figures, plus white or coloured, are enough for any supplier to send the right stock.

Find the right roll with the Omni thermal label finder

Once you have those measurements, you do not need to scroll through the whole range. The thermal label finder at the top of the thermal printing labels page narrows the options down in a few seconds.

Enter the label width, length and core in millimetres, choose the colour and your printer type, then select Find Thermal Label to see the matching rolls.

Not sure of every measurement? Leave the width, length or core blank and the finder will show the closest match. It is a quick way to check what suits your printer before you commit to a bulk order.

Sizing note: Label dimensions are shown in millimetres. A slight difference from the listed size usually will not affect how the label fits your printer. If you have any questions, get in touch through our Custom Thermal Label Quote form.

Choosing a supplier

Thermal label suppliers vary more on consistency than on price. Die cut accuracy, adhesive strength and coating quality decide whether barcodes scan first time and whether labels stay on cartons through a humid Queensland summer. Cheap stock that jams a printer or peels in transit costs far more than it saves.

Look for a supplier that stocks matching sizes across every core option, offers samples before a bulk commitment, and can produce custom dimensions when a standard size does not fit the application.

Browse Omni's label range or request a free sample to confirm fit before ordering in volume.

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