Use this guide to assemble an opening-by-opening purchase record. The baluster calculator supplies the fitted count; this record helps decide which counts can be repeated and which must stay separate.
Inventory the openings before adding quantities
Give each level opening a label on your sketch. Record its finished width between inside post faces, the actual baluster face width, and the project-selected maximum gap. Keep the source of that gap with the record; the calculator's preset is not approval for the project.
| Opening record | How to carry it into the order |
|---|---|
| Same clear width and same baluster/gap inputs | Calculate once and enter the number of identical openings. |
| Different clear width | Make a separate calculation; a visually similar opening may need a different count. |
| Spare balusters | Add the deliberate spare quantity separately from the fitted counts. |
Check the fitted count before multiplying
The calculator's eight-foot example uses a 96-inch clear opening, 1.5-inch balusters and a user-selected 4-inch maximum gap. It fits 17 balusters in one opening. Open Load this example to inspect the exact inputs and equal-gap result before using your own measurements.
For two genuinely identical openings, the fitted quantity is 34 balusters. Any entered extras increase the purchase total without changing either opening's gap or marks. Keep the installed quantity and extras on separate lines in your field record.
Turn the record into a purchase check
- Sum the fitted counts for separately measured opening groups.
- Compare the selected product with the recorded actual face width.
- Keep unequal openings labelled so a repeated order is not mistaken for a repeated layout.
- Recheck the first dry-fitted opening before cutting or fastening the rest.
- Transfer marks with How to space deck balusters evenly; the quantity record alone does not show placement.
The railing methodology contains the minimum-count and equal-gap equations. The measurement guide covers accepted feet, inches, fractions and metric notation.
Limits and sources
MaterialNest does not choose guard height, structural members, connections, or the gap allowed by your authority having jurisdiction. The 2021 IRC, Section R312.1.3 and the American Wood Council DCA 6 deck guide provide US code and deck context; DCA 6 itself says local approval and the controlling code still apply. The railing formula methodology documents MaterialNest's count and equal-gap equations.
If a formula, source, or explanation appears wrong, email feedback@materialnest.com.