“For low-risk indoor events, a common starting ratio is 1 security per 100 attendees, increasing to 1:50 when alcohol is served or exits are complex.”
Getting the right number (and mix) of security roles is the difference between an enjoyable event and a stressful one. This guide gives you a pragmatic starting point you can justify to venues, licensing, and your own stakeholders — and a calculator you can embed in your planning workflow.
Use the tool below to estimate SIA officers, stewards, and supervisors based on expected attendance and risk factors. You’ll get a printable breakdown, plus notes you can attach to an event plan.
Baseline
Low-risk, seated/controlled, indoor events commonly start around 1:100 overall headcount for total security personnel (SIA + stewards).
Alcohol & crowd energy
When alcohol is served, search and intervention needs rise; many planners move to ~1:50–1:80 depending on the profile.
Ingress/egress
Entrances and exits dictate friction. Plan at least 1 SIA per public ingress for ID/search control and to prevent bottlenecks. Complex egress (narrow corridors, multiple levels) increases stewarding needs.
VIPs & sensitive areas
Add licensed officers for VIP routes, back-of-house, and stage access. Consider CP-trained personnel where appropriate.
These rules-of-thumb support planning discussions — they don’t replace a site-specific risk assessment or licensing requirements.
Role focus
SIA-licensed officers handle access control, searches, refusals/ejections, and incident management.
Stewards support queueing, wayfinding, and crowd flow (particularly outdoors).
Supervision
Plan at least 1 supervisor per 12 staff, with a roving supervisor on multi-entrance sites.
Typical mixes (pick the closest starting point):
– Low-risk & dry events: 50% SIA / 50% steward
– Alcohol or high-energy: 70% SIA / 30% steward
– Mixed profile: 60% SIA / 40% steward
– Tricky venue geometry: multi-level spaces, blind corners, raised platforms.
– Late licensed hours: fatigue and incident probability increase after 22:00.
– Protest / reputation risk: add perimeter stewards and a dedicated radio channel.
– Young/rowdy demographic: reinforce SIA at search lanes and viewing barriers.
If in doubt, increase ingress SIA coverage and add a roving supervisor to keep the dashboard green.
Supervisors ≈ ≥1:12 staff; round up. Adjust for actual site geometry, ingress lanes, and licensing conditions.
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