Quick answer: Measure three things before ordering an EFTPOS or receipt paper roll: the paper width across the flat face, the outer diameter across the full circular roll, and the core opening through the centre. Record each measurement in millimetres, then compare all three with the paper specification in your exact terminal or printer manual. A label such as 57 x 30 mm usually describes a 57 mm paper width and a 30 mm outer roll diameter, but the device specification is the final check.
This guide explains how to measure a roll accurately, what common Boxy Packaging sizes mean, and how to avoid choosing a roll that is the right width but too large for the paper compartment.
What the numbers on a paper roll mean
For the thermal receipt rolls currently sold by Boxy Packaging, the first measurement is the paper width and the second is the outside diameter of a full roll. For example, a 57 x 40 mm roll is 57 mm wide and has a 40 mm outer diameter. The measurements describe physical size, not universal compatibility with every terminal.
Three measurements can affect fit:
- Paper width: the distance from one edge of the paper to the other. This must match the supported paper width in the device specification.
- Outer diameter (OD): the distance across the circular face of a full roll. A roll with too large a diameter may prevent the cover from closing or may rub inside the compartment.
- Core diameter: the opening through the centre of the roll. Some printers specify a required or minimum core dimension, while others use a drop-in roll and place less emphasis on it.
Roll length can be useful for comparing how often paper may need changing, but length alone does not prove that a roll will fit. Paper thickness, winding and core size can all affect the relationship between length and outer diameter. Match the physical dimensions first.
Tools you need
A metric ruler is enough for a practical check. A digital or vernier caliper can give a more precise reading, especially for the outer diameter and core opening. You will also need an unused roll or a nearly full roll. Measuring a roll that has already been used gives a smaller outer diameter and can lead to the wrong choice.
- A ruler marked in millimetres, or a caliper
- A new or full sample roll
- The make and exact model number of the terminal or printer
- The manufacturer's paper specification or user manual
How to measure an EFTPOS paper roll
1. Measure the paper width
Stand the roll on one circular end. Measure straight across the exposed paper from one edge to the other, without including any packaging. Keep the ruler perpendicular to the roll so the reading is not taken on an angle. A roll sold as 57 mm may measure close to, rather than exactly, 57.0 mm because printer specifications can allow a small manufacturing tolerance.
Write the width first. If your reading is about 57 mm, record it as 57 mm wide. If it is about 80 mm, record it as 80 mm wide.
2. Measure the outer diameter
Lay the full roll on its side so you can see the circular face. Measure across the widest part of the circle, passing through the centre. Do not measure around the circumference. Do not press hard enough to flatten the roll.
This second number distinguishes compact rolls from larger ones. A 57 x 30 mm roll and a 57 x 40 mm roll have the same nominal paper width, but the 40 mm roll needs more space inside the terminal. The larger roll is not automatically the better choice; it must fit the compartment specified for the device.
3. Measure the core opening
Measure straight across the empty opening in the centre of the roll. If using a caliper, use its inside jaws and avoid squeezing or distorting a paper core. Record the internal core diameter separately from the outer diameter of the core tube.
Check the wording in the printer manual carefully. A manufacturer may state an inner core diameter, an outer core diameter, or both. These are different measurements. Do not substitute one for the other.
4. Check the device specification
Find the exact model number on the terminal or printer label, then open the manufacturer's current manual or specification page. Match the supported paper width, maximum outer diameter and any stated core requirement. Similar-looking models from the same brand can use different rolls.
Official Epson specifications show why the model check matters. The Epson TM-m10 paper specification lists 57.5 +/- 0.5 mm paper and a maximum 60 mm roll diameter. The Epson TM-m50II specification lists both 57.5 +/- 0.5 mm and 79.5 +/- 0.5 mm paper options, with a maximum 83 mm diameter. These examples are not compatibility claims for Boxy rolls; they demonstrate that permitted dimensions are model-specific.
5. Test one roll before standardising
If the manual and measurements agree, load one roll before ordering around a mixed fleet of machines. The roll should sit squarely, feed without rubbing and allow the cover to close without force. Print a test receipt and inspect it for normal alignment and clear output. If several device models are used across a business, repeat the check for each exact model.
Compare current Boxy Packaging paper roll sizes
Boxy Packaging currently lists three relevant thermal roll formats. Use this table as a catalogue comparison, then confirm your printer's own specification before ordering.
| Current format | Verified listed dimensions | Pack | What to check |
|---|---|---|---|
| 57 x 30 mm EFTPOS paper rolls | 57 mm width x 30 mm outer diameter | 100 rolls | Designed for a smaller paper compartment than the 57 x 40 mm format. Core size and roll length are not stated on the current listing. |
| 57 x 40 mm EFTPOS paper rolls | 57 mm width x 40 mm outer diameter; 10.5 m listed length | 100 rolls | Confirm the terminal accepts a 40 mm outer diameter and that the closed cover does not press on the roll. |
| 80 x 80 mm thermal receipt rolls | 80 mm width x 80 mm outer diameter | 50 rolls | Intended for printers that accept the wider 80 mm class and an 80 mm roll diameter. Core size and roll length are not stated on the current listing. |
Browse the current EFTPOS paper rolls for the two 57 mm options. For the wider format, visit the POS receipt paper rolls collection.
57 x 30 vs 57 x 40: why width alone is not enough
A common buying error is matching only the 57 mm width. Both formats may enter the same width of paper path, but the full 40 mm roll occupies more space than the 30 mm roll. If the printer's maximum permitted roll diameter is below 40 mm, matching the width does not make the larger roll suitable.
Measure a new roll that is already known to fit, then compare that result with the exact model manual. Do not use a partly consumed roll as the only reference. If the old roll has no label, the outer diameter has already reduced and cannot reveal its original full size.
Brand name alone is also insufficient. A manufacturer may sell compact terminals, countertop receipt printers and wider POS printers with different paper bays. The exact model and paper specification matter more than the logo on the case.
How to load and test a thermal roll
- Switch to the loading procedure in the device manual and open the paper cover fully.
- Remove the old core and any loose paper fragments.
- Place the new roll in the direction shown by the manufacturer, keeping it straight and unbent.
- Pull a short, even paper tail past the cutter or cover edge.
- Close the cover without forcing it, then print a test receipt.
Square's Australian Square Terminal setup instructions advise using compatible receipt paper, keeping the roll unbent, closing the printer door and printing a test. They also advise reorienting the roll if the receipt prints blank. Follow your own device instructions because the loading direction and access method can differ.
Common measuring mistakes
- Measuring circumference: the second size is an outer diameter, measured straight across the circle, not around it.
- Measuring a used roll: its current diameter is smaller than the original full-roll diameter.
- Assuming 80 x 80 means 80 metres: in the current Boxy product specification, it means 80 mm wide by 80 mm outer diameter. No roll length is published for that item.
- Ignoring the core wording: inner core and outer core measurements are not interchangeable.
- Forcing the cover closed: pressure or rubbing indicates a fit problem. Stop and recheck the maximum diameter rather than compressing the roll.
- Choosing by terminal brand: paper requirements can vary between models from the same manufacturer.
- Using an unverified compatibility list: specifications and model variants can differ by region and revision. Prefer the current manufacturer manual for the exact unit.
Paper roll measurement checklist
- Confirm the exact device make and model.
- Measure a new roll's paper width in millimetres.
- Measure the full roll's outer diameter through its centre.
- Measure the core only when the device specification requires it.
- Compare each value with the manufacturer's current documentation.
- Check that the roll sits squarely and the cover closes without force.
- Print a test receipt before standardising stock across multiple devices.
Frequently asked questions
What size paper roll does an EFTPOS machine use?
There is no single roll size for every EFTPOS machine. The current Boxy range includes 57 x 30 mm and 57 x 40 mm EFTPOS rolls, but the correct choice depends on the exact device specification. Check width, maximum outer diameter and any core requirement in the manufacturer's manual.
Does 57 x 40 mean 57 mm wide and 40 metres long?
No. For the current Boxy Packaging product, 57 x 40 means 57 mm paper width and 40 mm outer roll diameter. That specific product separately lists a 10.5 m roll length.
Can I replace a 57 x 30 roll with a 57 x 40 roll?
Only when the exact terminal specification permits a 40 mm outer diameter. The paper width is the same nominal size, but the larger diameter needs more compartment space. Do not rely on width alone.
Why does a new roll fit but print blank?
One possible cause is that the thermal printing surface faces the wrong direction. Reload it in the orientation specified by the manufacturer and print a test. If the result remains blank, follow the device troubleshooting guide rather than assuming the paper is the only cause.
Should I measure the roll or trust the old box?
Use both when possible. Packaging identifies the intended full size, while a measurement can catch a labelling or stock mix-up. Measure an unused roll and verify it against the exact device manual before purchasing a large quantity.
Once the three measurements and device specification agree, choose the matching roll and keep the size recorded near the printer or in the purchasing system. That small step makes repeat orders easier and helps staff avoid mixing physically similar supplies.
