SettingsSettings for this calculationUS
The total length of frontage or opening to be protected by bollards.
Measure the full width of the opening or frontage that needs vehicle-passage protection.
The on-center spacing between bollards.
1.2-1.5m on center is a common spacing target to prevent vehicle passage while still allowing pedestrian movement between bollards.
Bollards needed
15 bollards
- Bays between bollards
- 14
- Bollard centres, as installed
- 4.71 ft
They open the calculator with your figures already in it
Security Bollard Spacing Calculator: 15 bollards — shown in imperial, US market. The link sets both, so the result they see is the one on your screen.
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How this was calculated
Formula source(s)
- Bollard count = ceil(protected length ÷ bollard spacing) + 1, the standard layout method for spacing security/traffic bollards (commonly 1.2-1.5m o.c. to prevent vehicle passage)
Inputs used
- Protected Frontage Length
- 66 ft
- Bollard Spacing
- 5 ft
Intermediate steps
- Bays between bollards
- 14
- Bollard centres, as installed
- 4.71 ft
What this calculation does not cover
- Spacing is handled as an on-centre dimension only, with no bollard diameter anywhere in the division, so the clear opening left between two adjacent units is narrower than the figure you enter by one shaft width, and nothing in the arithmetic tests that remaining gap for pedestrian, pram or wheelchair passage.
- The centres above are the installed ones, not the target you typed: rounding the interval count up before the end unit is added pulls them in tighter, so 20 m (66 ft) at 1.5 m (5 ft) is fourteen bays at about 1.43 m (4.7 ft). Set the line out from that figure rather than from the target, and read it against the clear opening above, which is the tighter of the two.
- The layout assumed is one continuous straight run with a bollard landing on each end, so frontage that turns a corner, follows a curve or butts into an existing wall or pier has to be measured as separate straight segments with the shared end units then deducted from the total.
- No allowance is made for a deliberate break in the line, such as a vehicle entrance, a loading bay or a service crossing fitted with a removable or retractable unit, because every position across the frontage is counted as one fixed bollard.
- Only the bollard count comes back: footing concrete, embedment or sleeve depth, baseplate fixings and the paving reinstatement around each position are quantities these two inputs cannot produce.
Estimated cost — your price
This site holds no price list for this material — local prices vary too much to publish honestly. Enter your supplier's price and the result is costed with it.
Computed in your browser — nothing you enter is uploaded. Presented in US customary units and US trade terminology. Where a formula follows a published standard, that standard and its edition are cited beside it on this page; where none governs, the page says so. Local amendments override model codes — verify against the code in force where you build.
Sources checked 2026-09-05 · in the site-wide review of 2026-09-06 · v1.0.1
Regulatory standards & verification citations1
- Bollard count = ceil(protected length ÷ bollard spacing) + 1, the standard layout method for spacing security/traffic bollards (commonly 1.2-1.5m o.c. to prevent vehicle passage)
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