Nobody Knows How Much of a Sermon People Forget. Here's What We Do Know.

The number everyone quotes

You've heard some version of it. Ninety percent of a sermon is gone within a week. Ninety-four percent by Wednesday. Seventy percent in 24 hours. The numbers show up in church growth books, conference keynotes, and software sales pages.

They showed up on ours too. At one point, our own materials cited six different versions of this statistic across the Lab, the Field Guide, and our conference page. So we went looking for the original studies behind them.

We couldn't find them. Not one of the popular figures traces back to a study of sermons, lectures, or anything like them.

This article corrects the record, starting with our own. It also explains why the real research is better news for pastors than the myth ever was.

What Ebbinghaus actually measured

Almost every forgetting statistic points back to Hermann Ebbinghaus, a German psychologist who published his famous forgetting curve in 1885.

Here's what he actually did. For seven months, he memorized lists of nonsense syllables (made-up sounds with no meaning, like the "wes" and "hom" used in a modern replication), waited anywhere from 20 minutes to 31 days, and then measured how much less time it took to relearn each list. He was his own and only subject.

His measure was called savings. If relearning took half as long as the first learning, he had "saved" 50%. That's not the same as remembering 50% of what he'd learned. It's a measure of effort, not recall.

In 2015, two researchers at the University of Amsterdam replicated his experiment and got a very similar curve. It's a real, repeatable finding about how memory for meaningless material fades. The replication's authors are careful to note that savings experiments work very differently from ordinary memory tests.

What it isn't is a finding about sermons. No one in these studies heard a message, a story, or a single sentence that meant anything.

Where the popular numbers come from

Some of the numbers are misreadings of Ebbinghaus. At about one day, his savings score was around 34%. Read carelessly as "34% remembered," that becomes "66% forgotten," and it gets rounded up to the "70% in 24 hours" you'll see on training websites.

Others have no traceable source at all. We found no study behind "90% forgotten within a week," and none behind "94% of a sermon forgotten by Wednesday." One figure about sermon recall in a German congregation circulates in ministry writing, but we couldn't locate the original study, its sample, or how it was scored.

The honest summary: no one has reliably measured how much of an ordinary sermon a congregation forgets, or how fast.

What the research does show

Researchers haven't measured sermon forgetting well. But they have studied, carefully and repeatedly, what makes any kind of teaching stick. Three findings stand out, and each one maps onto a step of the weekly rhythm Multiply is built on.

What this means for a pastor on Monday

1. Stop apologizing for the forgetting curve. It was never a verdict on preaching. It measured nonsense syllables.
2. Build one moment of recall into the week. Not a replay of the sermon. A question that asks people to bring it back to mind themselves: what's the one thing you remember, and why did it land?
3. Give people somewhere to talk. A small group, a text thread, a table after service. Listening alone rarely changes behavior.
4. End with one specific action. When, where, with whom. Specific enough that someone will know by Friday whether they did it.

What we're changing

We're removing every unsourced forgetting statistic from our own materials: this Lab, the Field Guide, our conference page, and our sales materials. In their place, we'll describe what the research actually shows, with its limits stated plainly.

We'd rather be trusted than dramatic. The evidence for how people learn is strong enough without borrowing numbers nobody measured.