How big should your casual bench be? A headcount formula for a Sydney venue that stops cover turning into a scramble
Your weekly hours tell you how many casuals you can keep busy, and your busiest night tells you how many you need. Here's the formula for both, worked through for a Newtown venue, and what to do with the gap.
Most venues size their casual list by feel, and it shows on Saturday at 4pm when three people are on leave, one has a uni exam and the group chat goes quiet. The fix is a sum, not a feeling. Your weekly hours tell you how many casuals you can keep busy, and your busiest night tells you how many you need on the books. Those two numbers are almost never the same, and the gap between them is where cover turns into a scramble.
The short version: hours headcount = weekly casual hours ÷ the hours each casual wants. Peak headcount = (heads on your busiest shift × (1 + drop rate) + 1) ÷ the share of casuals free that night. Hire to the hours headcount plus one. If the peak headcount is higher, don't hire the difference: plan to top up those nights from outside your list. This is general information about rostering, not legal or financial advice.
Why one headcount number doesn't work
Most advice on reserve staff stops at "keep a few extra casuals on the books". The trouble is that a casual you can't give hours to doesn't stay a casual for long. They pick up a second venue, stop answering, and you find out the next time you need them. We've covered that drift in why your casuals stop picking up shifts. So you're balancing two limits. Hire too few and Saturday night is short whenever life happens. Hire too many and everyone's hours get thin, so your best people leave first. A bench size that works sits between the two, and you can find it with four numbers you already have.
The four inputs
| Input | What it means | Where to find it | Newtown example |
|---|---|---|---|
| Weekly casual hours (H) | Casual hours on an average week's roster, not your peak week | Last 8 weeks of rosters, averaged | 300 hours |
| Hours wanted (A) | The average hours a week each casual actually wants | Ask them, then check against what they've taken | 20 hours |
| Drop rate (d) | Shifts lost to no-shows and drop-outs inside 24 hours, as a share of shifts rostered | Count them over the same 8 weeks | 6% |
| Peak availability (s) | The share of casuals on your books who are free for your busiest shift | Count who marked themselves available on the last 6 Saturday nights | 60% |
The fifth number is the one you know by heart: how many casual heads your busiest shift needs (P). For the example, take a 120-seat bar and dining room in Newtown that needs 10 casuals on the floor and behind the bar on a Saturday night. If you haven't pinned that down, covers per labour hour is the way to work it out.
The formula, worked through
- Hours headcount = H ÷ A. 300 ÷ 20 = 15 casuals. That's how many people you can give the hours they want. Go far past it and everyone's week shrinks.
- Peak headcount = (P × (1 + d) + 1) ÷ s. The 10 heads, plus 6% for the drop that will happen, plus one spare for the call you didn't see coming, is 11.6 people you need free. Divide by the 60% who are free on a Saturday night and you get 19.3, so 20 casuals.
- The gap = peak headcount − hours headcount. 20 − 15 = 5 casuals you'd have to hire only for Saturday nights.
- Your bench = hours headcount + 1. Sixteen casuals gives you one spare for sickness and leave without thinning anyone's week much. At 60% availability, 16 casuals puts about 9.6 free people against the 10.6 you need, so you're roughly one shift short on a typical Saturday night, and more in December.
Hire 20 to cover Saturday and the same 300 hours split 20 ways is 15 hours each, a quarter less than the 20 they asked for. That's the bench that walks.
Peak availability is the lever
Change the share of casuals free on a Saturday night and the answer moves more than any other input. Same Newtown venue, same 300 hours, same 10 heads and 6% drop rate:
| Free on Saturday night | Peak headcount | Gap over 15 | Hours each if you hired them all |
|---|---|---|---|
| 40% | 29 | 14 | 10.3 |
| 50% | 24 | 9 | 12.5 |
| 60% | 20 | 5 | 15 |
| 70% | 17 | 2 | 17.6 |
| 80% | 15 | 0 | 20 |
A venue that mostly hires uni students with weekend sport, or working holiday makers who travel on long weekends, sits at the top of that table. One that has a core of career hospitality casuals who want Saturday penalty rates sits near the bottom. Lifting peak availability by 10 points is worth more than five new hires, and the usual ways to do it are cheap: roster your Saturday regulars first, keep Saturday shifts long enough to be worth the trip, and ask about Saturday availability at the interview.
What the top-up night costs
Take that one short Saturday shift: six hours for a Level 2 food and beverage attendant. A casual at that level earns $40.62 an hour on a Saturday under the Hospitality Award from 1 July 2026, so the wage line is $243.72, plus $29.25 in super at 12%. Here's how the four ways to fill it compare at the same hourly pay.
| How the shift gets filled | On top of $243.72 pay | The catch |
|---|---|---|
| Hire a 17th to 20th casual | $29.25 super, plus onboarding every new hire | Thins everyone's week, and they drift |
| Ask a rostered casual to stay on | $29.25 super, plus overtime once they pass 38 hours (clause 11.4) | Your best people get tired first |
| Run one short | Nothing on the wage line | Nine people carry ten people's floor |
| On-demand cover inside the roster | $29.25 super, an 8% service fee plus GST ($21.45) and a $1.10 processing fee | A new face on your floor for the night |
For the venue that runs one short every Saturday, the cost of a no-show post adds up the lost covers. The on-demand line comes to about $22.55 a shift more than your own casual. Across 52 Saturdays that's about $1,170 a year, set against carrying four extra people you can't give hours to.
Keep the two groups separate. Your bench is your own casual staff, on your award and your payroll. On-demand cover is different: the venue engages an independent contractor for that shift, at rates at or above award minimums, plus super. Don't count those workers in your bench and don't roster them as extra casuals.
Rerun it three times a year
- Before December. Peak heads go up and availability drops as people travel. See your December staffing plan.
- Before February. Working holiday makers leave in clusters, so your H ÷ A number moves. Build the bench before February covers the leaving dates.
- After any month with three or more no-shows. Your drop rate has moved, and so has your peak headcount.
Where Shiftly fits
The formula needs two numbers most venues don't track: who's actually free on a Saturday night, and how many shifts fell over last month. Shiftly is free rostering, timesheets and award interpretation, so your staff's availability and leave sit in the roster you build from, and the scheduler marks a shift that clashes with them. When the sum says you're one short, you post that shift to the on-demand network from the same roster, and you read each shifter's profile and rating before you accept. It's the roster that fills itself, so you can hire to your hours, not your busiest night. Get started with Shiftly.
Frequently asked questions
How many casuals does a small cafe need?
Use the same sum. A cafe running 120 casual hours a week, with casuals who want 15 hours each, has an hours headcount of 8. If a Sunday brunch needs 5 heads and 70% of casuals are free, the peak headcount is (5 × 1.06 + 1) ÷ 0.7, or 9. A bench of 9 covers it with no gap.
What's a normal no-show rate for hospitality casuals?
There's no official figure, so measure your own. Count the shifts lost to no-shows and same-day drop-outs over eight weeks and divide by the shifts you rostered. If it's above 5%, the cause is usually thin hours or a late roster rather than the people.
Does carrying extra casuals cost money if I don't roster them?
Not in wages, because casuals are paid for the hours they work. The cost is onboarding each one, as in from yes to on the floor, and the attrition when their hours get too thin to bother with.
Can a casual work more hours to cover the gap?
Up to a point. Under the Hospitality Award a casual is engaged for up to 12 hours a shift and 38 hours a week (or an average of 38 over a roster cycle of up to four weeks), and time past that is paid at overtime rates (clauses 11.2 and 11.4).
Co-founder of Shiftly. Milan works with hospitality businesses across Australia to make rostering, timesheets and award-based pay radically simpler.
