Module-size formula
Bars and spaces should use consistent whole-dot multiples. Arbitrary scaling can create uneven modules and reduce scan performance.
X-dimension in mm = module dots ÷ actual dots/mm
Approximate module span = total modules × X-dimensionCandidate module sizes
| Dots | 8 dots/mm | 12 dots/mm | 24 dots/mm |
|---|---|---|---|
| 2 | 0.2500 mm | 0.1667 mm | 0.0833 mm |
| 3 | 0.3750 mm | 0.2500 mm | 0.1250 mm |
| 4 | 0.5000 mm | 0.3333 mm | 0.1667 mm |
| 6 | 0.7500 mm | 0.5000 mm | 0.2500 mm |
| 8 | 1.0000 mm | 0.6667 mm | 0.3333 mm |
Worked example at 12 dots/mm
For a requested 0.33 mm module and candidates from two to six dots, four dots is closest at 0.3333 mm, approximately +1.01%. Ten quiet-zone modules occupy about 3.333 mm per side. Check acceptability against the governing specification.
Production checks
- Identify the exact symbology and application standard.
- Reserve required quiet zones and symbol height.
- Avoid non-integer resizing after generation.
- Print on production media and verify to an agreed quality target.
Frequently asked questions
Is there one minimum X-dimension?
No. Allowed ranges depend on symbology, application, data, substrate and scanning conditions.
Is the closest dot count compliant?
Not automatically. It is only the closest raster match; use the range permitted by the governing specification.
Run the calculation
Use your own measurements in the browser-based calculator. Inputs are processed locally and are not uploaded to LabelOps Lab.
Open the Barcode X-Dimension CalculatorRelated guides
Last reviewed: