Dial level calculator
Dial level is how many lines a predictive dialer runs for each agent. A steady-state estimate is the average dial time divided by the answer rate times the seconds each agent spends per call. With 25-second dials, an 8% answer rate and 165 seconds per call, that comes to about 1.9 lines per agent.
How the estimate works
It balances how many connected calls the lines can deliver against how many your agents can take. Each line spends an average of D seconds per dial, and a share p of those dials reach an agent, so one line hands over p ÷ D calls per second. Each agent can take one call every T + W seconds: talk and wrap time, plus the wait you're willing to give them between calls. Set the two equal and the dial level drops out:
dial level = D ÷ (p × (T + W))
A lower answer rate or shorter talk time pushes the level up, because each agent burns through answers faster than the lines find them. Longer dials push it up too, since a line spends more of each minute ringing out. More wait time pulls it down, which is the trade every floor makes between idle reps and dropped calls.
Why the real number keeps moving
Answers don't arrive on a schedule. They bunch up, so a floor dialing at exactly this level will sometimes have a person on the line with no free agent, which is a drop, and sometimes an agent with nobody to talk to. That's why a predictive dialer recalculates through the shift instead of holding one number, steering the level against a drop limit and stopping at a maximum the admin sets.
Treat the result as a starting point and a sanity check. If your dialer runs far above it while drops climb, the list's real answer rate is probably lower than the one you entered. If it sits far below and agents wait, look at the dialer's cap and how it counts agents, since some only dial for agents who are free right now.
Below 1.0, the list answers well enough that one line per agent keeps everyone busy, and fixed pacing will do. The guide to power dialer vs predictive dialer covers when that's the better fit.
Getting good inputs
Pull them from the last few days of the same campaign, not a different list. Answer rate here means the share of dials that actually reach an agent: live people, plus answering machines if machine detection is off, since those land on agents too. Dial time is the average a line stays busy per attempt, ringing included. Talk time should include wrap-up, because an agent finishing notes can't take the next call. Run it again when the list changes, since a fresh list and a third-pass list can answer at very different rates.
How Hershel does it
Hershel is an AI dialer built on a proven open-source dialing engine, then rebuilt around AI: its own rep console, its own manager screens, and AI that runs dial pace, caller IDs and call notes.
Its Dialler Manager doesn't work from a fixed estimate. It reads live campaign stats and adjusts the dial level so agents talk to as many people as possible while the drop rate stays under the ceiling the floor sets. The full picture is in what an AI dialer is and the platform overview.
Frequently asked questions
What is a good dial level for a predictive dialer?
It depends on the list. The level that keeps agents busy comes from your answer rate, dial time and talk time, which is what this calculator estimates. A list that rarely answers needs a higher level, and one that answers well needs a lower one.
How do you calculate dial level?
Divide the average dial time by the answer rate times the seconds each agent spends per call (talk, wrap and the wait you allow). With 25-second dials, an 8% answer rate and 165 seconds per call, that's 25 / (0.08 x 165), or about 1.9 lines per agent.
Why does a higher dial level cause more dropped calls?
More lines per agent means more answers arrive at the same moment. When answers outnumber free agents, the extra people are dropped. Adaptive dialers raise and lower the level through the shift to keep drops under the limit the floor sets.
Should I set my dialer to the calculated number?
Use it as a starting point and a sanity check. Answers come in bursts, so the right level moves with the hour, the list and how many agents are logged in. If your dialer adjusts the level on its own, let it, and check that its cap sits above this estimate.
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