Your discovery call is 15 minutes too long: how long should a discovery call be?
A 15-minute pre-interview qualifies better than a 30-minute discovery call. You can do twice as many, and you cut the bad ones before they cost you an afternoon.
On July 14 a partner who runs his own show told Charles and me what he'd changed:
"So I've changed the actual podcast to only be a 30 minute window."
He'd moved his slots to 30 minutes, with buffers on both ends, and dropped the short pre-interview. We pushed back, both of us.
How long should a discovery call be? For a founder qualifying inbound or outbound interest, 15 minutes. Ten minutes where they talk, five where you decide. If they're a fit, book the next step on the spot. If they're not, you've lost a quarter of an hour, not half of one.
The 30-minute slot with buffers on both ends
I understand why he did it. Thirty minutes feels respectful. Buffers feel professional. You get time to prep before and write notes after.
But do the math on a day. A 30-minute call with a 15-minute buffer on each side is an hour of calendar per conversation. That's maybe six conversations on a heavy day. A 15-minute call, stacked, is four per hour.
The recommendation we gave him was specific: keep 15-minute pre-interviews for scale, and aim for 5 to 10 a day. Fifteen-minute slots give you twice the volume of 30-minute ones before you even count the buffers.
Why 15 minutes is enough
The structure is what makes it work. On our July 6 team call we wrote it down: first 10 minutes, let them talk and collect data. Last 5 minutes, go for the close if it's a fit.
Ten minutes of listening is plenty to hear the big things. What they're building. What's broken. What they've tried. Whether the person on the call can say yes. You're not trying to diagnose everything. You're trying to answer one question: is this worth a second conversation?
The 30-minute version usually fills the extra time with the seller talking. Demos nobody asked for. Background on the company. Case studies. That's not discovery. That's a pitch wearing discovery's clothes.
I bookmarked a post in early June that put it well: a discovery call has one job, to collect enough to write a strategy document so good the next call closes itself. Fifteen focused minutes gets you that document. Thirty unfocused ones get you a longer recording.
Cut early, close early
The other half of our advice was about permission to end. If it's not a fit, cut early and move on. If it's a good fit, go for the close.
Most people do the opposite. They give a bad-fit call the full 30 minutes out of politeness, and they rush the good-fit call because they're running out of time. A short default flips that. Bad fits end at minute eight with a kind "this probably isn't for you, here's who might help." Good fits get booked for the next step before you hang up.
On a show-led pipeline the pre-interview is the Trojan horse. The prospect thinks they're preparing for an episode, and they are. But the relationship is the real goal, and 15 minutes of genuine interest in their story builds more of it than 30 minutes of anything else.
Those last five minutes can do more than you think. On our July 6 team call we decided to test a simple close: ask the prospect to switch their screen share to their own calendar. If the problem is pipeline, an empty week makes the case faster than any slide. It takes a minute, it is their data, not yours, and it turns "we could use more meetings" into something both of you are looking at.
A client call earlier that week added the operational rule that goes with it: book the next slot during the call, not in a follow-up email. Every email between "yes" and a booked time leaks people.
Remove the buffers, let AI do the prep
The buffer is there for prep and notes. Both can be handled without blocking your calendar.
The fix we gave the partner: remove the buffer before slots so calls can stack. For prep, AI handles it and drops notes into the calendar event 15 minutes before each call: who they are, what they do, what they said when they booked. You read it in the minute before you join.
Notes after the call are handled the same way. A note-taker captures the conversation, and the follow-up gets drafted from it. You don't need 15 minutes of white space to remember what someone said.
The real bottleneck: a calendar booked weeks out
Here's why this mattered to us that week. At the time, Charles was booked three weeks out. I was about a week and a half out.
That's a good problem, but it's still a problem. Every week between someone saying "yes, let's talk" and the actual call is a week for their interest to cool. Long slots make the backlog worse. Short slots clear it.
If your calendar is booked out, don't add hours. Shorten the unit. Fifteen-minute calls at 5 to 10 a day will clear a backlog that 30-minute calls never will.
When a longer call is right
Not every call should be 15 minutes. The second conversation with a qualified buyer, the one where you walk through a proposal or a plan, deserves 30 or more. So does the show itself, and the debrief after it.
But the first call is a filter. Filters should be fast. Make the first call short, the second call specific, and let the buyer's interest earn the longer ones.
If you want to see how we book and stack those calls, see how calls get booked.
Frequently asked questions
How long should a discovery call be?
Fifteen minutes for a first qualifying call: ten minutes for them to talk, five for you to decide and book the next step. Longer calls belong to buyers who have already qualified.
Is 15 minutes enough to qualify a lead?
Yes, if you spend it listening. You only need to know what they are building, what is broken, whether they can say yes and whether a second conversation is worth it. Cut bad fits early.
Should I put buffers between sales calls?
We removed them so calls could stack. AI drops prep notes into each calendar event 15 minutes before the call, and a note-taker handles the follow-up, so the white space is not needed.