Call conversions in Google Ads: what minimum call length should count?

Take a plumber's Google Ads account that reports 40 calls a month as conversions, where a chunk of them last under 15 seconds. Wrong numbers, people hanging up at the hold message, spam calls. Google lets you set a minimum call duration for call conversions, and people pick anything from 10 seconds to 2 minutes.

I think 60 seconds is a reasonable starting point for most home services, though it depends on the trade. A locksmith gets quick, valuable calls, so a 30-second floor might be fine there. A law firm's intake calls run longer, so a short call usually means a bad fit and shouldn't train the bidding. Where do you set it, and does anyone check it against booked jobs?

Sixty seconds is a fine starting guess, but I'd test it instead of leaving it alone. Bucket your calls by length (under 30, 30 to 60, 60 to 120, over 2 minutes) and see which buckets actually turn into booked jobs. If the 30 to 60 second bucket converts at a real rate, your floor is cutting out customers and bidding is learning the wrong signal. Length is only a proxy for quality, and for a locksmith a short call can be the valuable one.

Is the booked-job data in the same system as the call logs, or does someone match them by hand?

Keep the call duration floor low, around 30 seconds, just to filter out wrong numbers and hang-ups. Then feed booked jobs back as offline conversions so bidding learns from actual jobs instead of call length.

I'd keep the floor low to filter out junk, but the offline side is where this usually stalls. Bidding only learns from booked jobs if you can tie each job back to the call that produced it, and a caller's number alone won't reliably match to a click. So my rule would be a floor around 30 seconds to catch wrong numbers and hang-ups, and only send a call as a conversion when the job can actually be matched. If the matching is manual, do it monthly and compare booked rates by length bucket instead of going call by call. A small sample of matched jobs teaches you more than a big pile of unmatched calls.

Agreed on the matching problem, and I'd push it further. For a lot of home services, the call-length floor matters less than whether the call came from a click at all. Organic and direct calls to the same number get counted right alongside paid ones, so no length cutoff can fix that. How big a problem it is depends on what share of your calls come from ads versus everywhere else, and that's the first thing I'd check.

It comes down to which number the caller actually dials. If it's only the ad or call extension number, Google credits just the ad-driven calls. If your website swaps in a tracking number for some visitors, the swap rules decide who gets credited, and a loose setup can pull organic callers in too.