4 mm bead size
See a 4 mm round bead at actual size, convert to inches, and work out how many you need for a bracelet or necklace. Spacers, accents, and multi-strand designs; small enough to read as texture rather than as individual focal beads.
4 mm bead at actual size
Calibrate to your screen (or print) so this circle is physically 4 mm across.
Printed at 100% scale, the marks below should measure exactly: the gold line = 1 inch, the "50" tick = 50 mm. If not, set your print scale to 100% (not "fit to page").
How many 4 mm beads do you need?
4 mm in context
| Size | Inches | Per inch | Per 16″ strand |
|---|---|---|---|
| 3 mm | 0.118″ | 8.5 | 136 |
| 4 mm | 0.157″ | 6.3 | 100 |
| 6 mm | 0.236″ | 4.2 | 67 |
4 mm vs neighboring sizes
Calibrate above to compare these at true physical size.
Printed at 100% scale, the marks below should measure exactly: the gold line = 1 inch, the "50" tick = 50 mm. If not, set your print scale to 100% (not "fit to page").
Sources, calibration & how the counts are computed
On-screen sizes are only accurate after you calibrate your display to a real credit/debit card (ISO/IEC 7810 ID-1 = 85.60 mm wide). Before you calibrate, beads are shown NOT to scale. For a guaranteed-accurate size, use the print view at 100% with the printed ruler.
Beads per inch and beads per strand use the standard estimate beads = round(length_in x 25.4 / diameter_mm), where 1 inch = 25.4 mm. Counts are approximate; actual bead lots vary.
Data basis: Diameter is the nominal bead size; 16-inch-strand count from Fire Mountain Gems (matches the 25.4/mm-per-inch invariant).
Last reviewed 2026-06-18.
General jewelry-making reference. Bead dimensions are approximate and vary by manufacturer, material, and finish; measure your own beads with calipers when precision matters.