The short answer is, "it depends."
The medium response is 25-30.
This is the long answer:
When it comes to figuring out how many requisitions a recruiter should be able to handle, the variables are limitless. Nevertheless, I will mention the more notable considerations and some reasoning for each.
Quality of Hire
If you want the best of the best, its going to take a lot of selling to convince them to join your firm. Whether or not you represent a Fortune 50 company or a lower 1,000. If the person you want to hire is really good, chances are you will be competing with other companies who want them as well. On the flip-side, if the role is not so critical and average workers are acceptable, a larger requisition load is not unreasonable.
Passive vs Active candidates
What type of candidate are you focused on? If you are targeting passive candidates, its going to be a longer sales cycle; such is the nature of that type. If you are grabbing people from a job board, a larger requisition load is not unreasonable. Moreover, its a logical assertion to say that the higher level of the job, the smaller the load.
The best recruiters know how to get things done whereas newbies have a learning curve. The proficiency of the worker has a direct impact on how much work can be handled. This is especially true if the recruiter has to source their own candidates.
If a recruiter is handling many different types of jobs then, I would think a smaller requisition load is logical because the recruiter will not be able to submit their candidates to multiple roles.
If there is a low offer-acceptance rate, then requisition loads should be lowered; chances are so many searches will have to be extended or reopened. That being said, what do the company's Glassdoor ratings look like? Is there a lot of turnover in the company? What does the stock price look like? Is the ticker trending down or up? If the employee referral rate is low, that suggests a difficult culture to recruit for.
If there is a recession in play and layoffs are common in the headlines, chances are candidate response rates will be high. On the other hand, if the economy is booming and the unemployment rate is low, recruiters will have to wait longer to hear back from potential hires.
How responsive are the hiring managers? Do they reply to emails in a timely manner? Do they constantly cancel interview dates? The best recruiters are the ones who can best manage the hiring managers they support. It is worth mentioning, some hiring managers purport to be too busy to stop working long enough to interview the help they desperately need.
Is the recruiter scheduling the screens, interview times, extending offers and on-boarding? Without the assistance of a recruiting coordinator, these duties can really extend the time to fill and requisition load tangentially.
What resources are available to the recruiter? Do they have access to LinkedIn Recruiter? Monster? Do they have sourcing support?
Although there is no universal standard applicable to every industry, personal experience and anecdotal evidence say 25-30. Said number is set on a mix of reqs; some high level passives, some active job seekers with a couple of purple squirrels filtered in. As you may imagine, this is a very controversial topic among recruiters (and sourcers for that matter.) I scanned the web to find commentary from recruiters on the topic. (See below) I also suggest checking out SourceCon's State of Sourcing surveys as their data is invaluable on this topic.
ADDITIONAL INSIGHTS FROM THE WEB
"...I'm a corporate recruiter and had a high of 48 openings at one time across 4 business groups (Marketing, Finance, Technical Sales Support [but not IT] and Purchasing). I average between 25-30. I've been there since June and have filled 45 positions, but that does include some internal moves (although I still have to coordinate internal interviews and help w/ salary discussions). We have a total of 4 recruiters, a coordinator, and a req carrying Director - will probably hire 300 or more in the next year including a whole lot of entry level college grads - we have a campus recruiter who focuses on that. Don't hold me to that number- I'm taking a stab based on what I've seen this year and what I've heard as far as planning in my client groups." [source]
"This is not a cut and dry type of answer. It really depends on how many openings you have, what level those opening are (non-exempt, exempt, manager, director, etc.), how "rare" or "common" the skill set you're looking for is, if it's a relocation position, etc. If you are an internal recruiter and working for a large corporation then your work load is probably 20 to 30 openings, at varying stages, at any given time. Therefore 8 to 12 hires per month would be about right. If you work for a midsize company, on average you probably have 10 to 15 openings and 6 to 8 hire per month is about what you'd expect. Smaller firms, (300-500) employees I'd expect your monthly job openings to average around 5-10 positions, therefore 0-5 hires per month. It really depends on so many factors and circumstances that I might think an average of 5 hires per month is great, and someone down the street will think that sucks! I've recruited for every scenario and size company I've described above and those are about what I used to average." [source]
"On a large recruiting team, your chance to fill openings is obviously decreased if you are all recruiting from the same talent pool. Also if you are only supporting 2 hiring managers you won't fill as many positions as a lone recruiter who supports many managers in the organization. Supposing there are an endless number of positions to fill each month for your two managers, a good recruiter should be able to fill at least 10 entry level positions, and 3-4 high level positions. If it's just one or the other (entry or high level) those numbers obviously go up. All of this is also highly dependent on the hiring process within the organization. Some are much slower than others." [source]
"I filled about 85 positions each year while working for large company. These were IT Jobs. Small companies. I filled 20 to 30 positions this year. Currently recruiting for company that 650 employees. I am on track to fill about 60 - 70 this year. So about 5 people per month this year. All IT jobs." [source]
"The question is not so much how many can they fill but how many can they "effectively support at one time." After reviewing our processes and streamlining efforts we are confident that our high volume recruiters can manage 80-100 positions which could translate into three to four open requisitions. Our high volume positions have set start dates in order to meet training class timelines. If a recruiter misses then we can roll those positions into the next req with a post mortem to try and avoid in the future (source, process, hiring manager responsiveness, failed background checks). If the positions are ongoing with no set start date for training, being a midsize company, growing fast and that you mention "improving their internal process" I would agree with Peter's numbers - 6-8." [source]
"...depends on what the recruiter and the client want to have happen and what is valued most. As an onsite corporate recruiter, I most value being able to deliver high quality service. In my experience, high quality service = high quality results. For me personally, that means 30 req's at the most. Anything after that, for a sustained period of time, my ability to deliver high quality service suffers." [source]
"The number depends on the effort expended to fill the role. If you are proactively recruiting hard to find candidates I'd say about 1 -2 a month is about right If you are running ads or just reviewing write-ins on your ATS then you are no longer actively recruiting and the number could easily be 12-15+ open jobs on an on going basis." [source]
"In my role, I recruit for all roles. Since we don't have any high turnover roles and only a couple entry level type roles, we focus heavily on quality over quantity. I'm comfortable at 10-12 on an ongoing basis if that mixed between individual contributor roles and some management roles. 15 is my stretch for frontloading and peak periods. Since I currently have 30 openings, I hired a temp recruiter to help me. It all really depends on the role of the recruiter at the organization. So much of my role is employer branding, networking, blogging, and attending a significant amount of career fairs. So it's possible that my metrics are a little more modest than some. But again, my role goes beyond just back to back phone screens all day." [source]