What call length should count as a conversion?
There is no universal number. Measure your own calls: bucket them by duration, look at the booking rate in each bucket, and set the threshold at the point where booking rate stops being negligible. Sixty seconds is the common default because it filters hangups and wrong numbers, but a shop whose dispatcher books in forty seconds and a shop that quotes on the phone will have very different curves.
Why the default exists, and why it is arbitrary
Sixty seconds became the standard because it is long enough to exclude misdials, hangups and voicemail deflections, and short enough that it does not throw away real leads. It was never derived from anyone's data.
The cost of getting it wrong runs both ways. Set it too low and you feed the bidding algorithm a pile of non-leads. Set it too high and you starve it of signal while quietly discarding the fastest, most efficient bookings your team makes.
How to find your own threshold
Pull every tracked call for a period long enough to include a few hundred calls. Bucket them by duration in fifteen-second increments. For each bucket, calculate the share that resulted in a booked job in your field service system.
You will see a curve with a knee: booking rate near zero at the short end, then a steep rise, then a plateau. Put the threshold just before the knee. Recheck it after any change to how calls are answered — a new answering service or a script change moves the curve.
What duration can never tell you
Duration is a proxy for intent, and a crude one. A four-minute call can be a job applicant, a supplier, an existing customer rescheduling, or a homeowner arguing about an invoice. All four clear a sixty-second threshold and none is a new lead.
This is the ceiling on duration-based conversion tracking. It cannot read the call. Analyzing the conversation itself can tell a new service request from a callback, identify the service line, and flag calls where the caller wanted to book and did not — which is a different and more actionable problem than a short call.
Outcome-based conversions are the upgrade path
Once calls are classified by what actually happened, you can stop using duration as the conversion trigger entirely. The conversion becomes "qualified new service request," and later, once the job is booked, a second event with a real value.
That is the point at which smart bidding starts optimizing toward work instead of toward ringing phones. Getting there requires the call platform, the CRM and the ad account to share identifiers, which is the ordinary substance of AI systems integration rather than anything exotic.
Topics: call tracking · call duration · conversion thresholds · lead quality
Have a version of this question about your own business?
The useful answer usually depends on which systems you run and how they're connected. That's a conversation, not a blog post.