Within one minute. That's the short answer, and it's been the answer since 2012. The longer answer: the studies behind it are older than most people quoting them realize, nearly all were run by companies selling dialers, and they still all point the same way. Here's the timeline, what each one measured, and what changes when the first call goes out in about 10 seconds instead of five minutes.
2007: the five-minute rule is born
The Lead Response Management study by Dr. James Oldroyd, then at MIT, was run with InsideSales.com on six companies, roughly 15,000 leads and more than 100,000 dial attempts. Its two findings became the industry's catechism: the odds of contacting a lead were 100 times higher when the call went out within five minutes rather than 30, and the odds of qualifying the lead were 21 times higher (InsideSales/XANT, 2007 study referenced in 2011 release).
Six companies is a small sample. Read the multiplier as "very large," not as a precise 100.
2011: HBR audits 2,241 companies
Oldroyd, Kristina McElheran and David Elkington followed up in HBR with an audit of 2,241 U.S. companies that had received a web lead. Among the findings: 37% responded within an hour, 16% within one to 24 hours, 24% took more than 24 hours, and 23% never responded. Average response time among companies that did respond was 42 hours. Firms that tried to contact the lead within an hour were nearly seven times as likely to qualify it as firms that waited even an hour longer, and more than 60 times as likely as firms that waited a day or more (HBR, 2011).
2012: the first minute, measured
Velocify's Ultimate Contact Strategy analyzed about 3.5 million leads from more than 400 of its clients, generated in the first half of 2012. Leads called within one minute of inquiry were 391% more likely to convert than leads called later. The lift fell to 160% in the second minute and 98% in the third (2012 study, reported 2013).
This is the study that moved the target from five minutes to one. Look at the shape of the curve: the gain is front-loaded, and most of it's gone by the end of minute three.
2017: almost nobody does it
Drift audited 433 companies by submitting a form and timing the reply. Only 7% responded within five minutes and 55% took more than five business days (Drift, 2017). Five business days, to a form that said "contact me."
2020: an insurance-specific secret shopper
AgencyZoom submitted a uniform lead to 150 independent insurance agencies. The results: 6% responded within five minutes, 30% within an hour, 34% never. Top performers averaged three minutes (HawkSoft, 2020).
2026: two fresh data points
Blazeo surveyed 573 service companies in February 2026. Of the leaders polled, 35.4% said a five-minute response is essential, but 38% of that group admitted they fail their own standard. 81.2% of companies responding in over an hour reported losing leads to slow follow-up. More than 40% of high-intent inquiries arrived evenings or weekends (Blazeo, 2026).
Workato submitted demo requests to 114 B2B companies in March 2026. Zero called back within five minutes, 42% called within an hour, and 69% never called at all. Average phone response among those who did: 14 hours 29 minutes (2026).
The honest caveat
Three things to hold alongside those numbers.
First, the foundational studies are from 2007 to 2012. Smartphones, form-fill fatigue and spam-call labeling have all arrived or changed since then. Nobody has published a replication at the original scale.
Second, InsideSales, Velocify, Drift and Blazeo all sell response tools. That doesn't make the data wrong, but it does mean the framing favors speed. HBR's 2011 piece is the closest thing to a neutral audit, and it measured whether companies responded, not whether leads converted.
Third, "391% more likely" is a relative lift from a low base. If 2% of late-called leads convert, the first-minute group converts around 10%. Large, real, and still a minority.
What survives the caveats is the direction. Every study, across 19 years and five industries, says the same thing: the first minute is worth more than the next hour, and most companies don't get there.
Why minute one beats minute five beats hour one
Nothing mysterious here. At minute one the lead still has the form open and the phone in hand. The question they typed is still the question in their head. At minute five they've usually submitted the next form, because the first site didn't call. By hour one they've talked to whoever did call, and now you're the interruption. A day or two out, which is where the 2011 average sits, they've moved on or forgotten they ever asked.
What "about 10 seconds" changes
RevStrike's agent dials a new lead within seconds of the form post, about 10 seconds end to end, inside permitted calling hours. I want to be careful about what that does and doesn't buy you.
It doesn't buy a bigger multiplier than minute one. The Velocify curve is already flat at the top. What it buys is certainty. A human team that hits one minute on every lead, evenings and weekends included, doesn't exist. I haven't met one, and I talk to a lot of owners. An automated dial at 10 seconds is the same on the 400th lead of the day as on the first, and it covers the 40% of inquiries that land after hours.
It also changes the opening line. At 10 seconds the shopper hasn't left the page, so the call can open with "you just asked about..." and the shopper knows exactly why their phone rang.
What it doesn't do is make the lead pick up. Contact rate still depends on the person on the other end, which is why the number to watch isn't seconds-to-dial, it's conversations-per-lead. More on measuring that in Does AI appointment setting work?.