How Many Nurses Do We Need to Hire?
Put in the posts, the turnover and the time to fill and get back the empty posts and cover cost to expect. A 42-post unit at 19% turnover carries about two empty posts all year and $253,000 of cover. Filling posts faster matters more than losing fewer nurses, and the tornado says so.
Nursing Intermediate Monte Carlo Pro engine
After you install, this is the model to open.
How Many Nurses Do We Need to Hire?
- In your spreadsheet, click the Sortia icon in the strip of icons down the right-hand edge. No strip? Click the arrow at the bottom-right to open it. You can also use Extensions, then Sortia, then Open Sortia.
- Click Start from a template and put that name in the search box.
- Pick the card with that name and click Load this template. It arrives on a new tab with real numbers already in it.
This one runs on a Pro engine, and every free install includes five full-quality runs on your own numbers, shared across all five Pro engines rather than five for each. After that, Pro is $199/year.
What it does
A 42 FTE unit with 19% turnover loses about eight nurses a year, and each post sits empty for about eleven weeks while it is recruited. That is 88 vacant FTE-weeks, which is 1.69 posts standing empty at any moment, 4% of the establishment, and $221,000 of overtime to cover it. Every one of those numbers is on the sheet and every one of them is a single guess.
Neither turnover nor time-to-fill is a number you know in January. Click Run with turnover between 12% and 32% and time-to-fill between 6 and 22 weeks. The average number of posts standing empty is 1.93, the median 1.85, and the 90th percentile 2.75. The cover cost averages $253,000 with a median of $242,000, a P90 of $361,000 and a P95 of $398,000.
So the plan built on the point estimate is not merely uncertain, it is optimistic: the single-number answer of $221,000 sits below the median of the simulated ones, which is what happens when you multiply three best guesses together. Now the finding worth the whole model. The tornado puts weeks-to-fill first at 0.79 and turnover second at 0.59.
How fast you fill a post matters more than how many people leave. That is the opposite of where the attention goes, because retention is the thing hospitals hold meetings about and recruitment lead time is treated as an administrative fact. Cutting time-to-fill from eleven weeks to seven does more for this unit than cutting turnover from 19% to 15%, and one of those is inside your control in a way the other is not.
Rerun with the time-to-fill range set to 5, 7 and 12 and read the cost drop. Two things it cannot see. It treats every leaver as replaceable by a hire, and a specialist post is not, so a unit losing its two theatre-trained nurses has a bigger problem than this arithmetic shows. And it ignores the productivity ramp: a nurse hired in week 11 is not a full nurse in week 12, which makes the real gap wider than the model draws it.
To make it yours, use your own establishment, your own leaver count from last year, and your own median time-to-fill, which HR will have and which is usually worse than anyone believes.
The model
It arrives on a tab called Template: How Many Nurses Do We Need to Hire:
| Hiring plan for a 42 FTE unit | |
| Budgeted RN posts (FTE) | 42 |
| Annual turnover rate | 0.19 |
| Weeks to fill a vacancy | 11 |
| Nurses who leave this year | 7.98 |
| Vacant FTE-weeks created | 87.78 |
| Average posts sitting empty (count) | 1.688 |
| Share of the establishment unfilled | 0.04019 |
| Hours one FTE post covers in a year | 2080 |
| Overtime cost an hour to cover it | 63 |
| Cost of the vacancy gap for the year | 221,205.6 |
Once it is in your sheet
- The model arrives with real numbers in it and runs as it stands, so you can press the button first and understand it second.
- Change the numbers to yours. The sheet marks which cells are inputs and which hold formulas, and most labels carry a note explaining the row.
- Press the run button at the bottom of the panel. It is labeled for the tool you are in, and the result lands on its own tab, with a written reading of it beside the figures.
Never used Google Sheets? Start here goes the whole way, in seven steps, and assumes nothing.
Next question
- Put in the patients, the nurses rostered and how often people call off and get back the odds the shift runs short. Twenty-seven patients, six nurses, four and a half each. The sheet says the shift is fine. Ten thousand simulated nights say it runs below ratio on a third of them, and call-offs, not the census, are why.Will the Roster Hold Tonight?
- Put in the shifts each nurse works and get back who carries the weekends and nights. Eight nurses, twelve shifts each, and it still is not equal: one works five weekends and one works one. The month looks fair in total hours and is not fair in the hours anybody minds.Is the Roster Fair?
- Put in the shift hours, the rate and your tax and costs and get back what the extra shift really leaves you. A twelve-hour overtime shift at $42 an hour with a night differential grosses $822 and leaves you $431.96. That is $36 an hour for a shift that pays $63, and just over half of what it looked like.Is the Extra Shift Worth It?
- Thirty-six hours of vacancy costs $2,268 on your own staff and $3,520 through an agency. The agency only wins if your overtime multiplier reaches 2.33, and almost nobody pays that.Overtime or Agency?
- Two nurses on call cost $624 on a normal night. Across ten thousand simulated nights they average $808, and the worst reaches $3,396, which is the number the stipend line never shows.How Many Nurses on Call?
- Two experts, one schedule. Where is the settlement zone?Delay Claim: Who Owns the Days?
Every model like this one, and the method behind them: Monte Carlo simulation.