Ninety minutes is a habit, not a law
There is no correct duration, only durations that fit the material and durations that do not. Write the running order first, add it up honestly, and the length tells itself.
The common answers circulate as rules: an hour is standard, ninety minutes is professional, anything under forty minutes is not worth an invitation. None of them are derived from anything. They come from an era when a webinar imitated a conference hall, where a slot was a slot and the speaker fitted the material to it. A rule borrowed from a physical agenda has no business governing a session you are planning on a Tuesday.
The real constraint is attention, and attention is not a fixed tank that drains on a clock. People stay with a session that is moving and leave one that is circling, whatever the minute. A forty-minute talk with a clear argument and three things to take away will hold a room; a ninety-minute one that spends thirty of them on housekeeping will not. So the question is not how long a webinar should run. It is how long your material takes to say properly, and whether you have the discipline to stop when it is said.
Rough shapes rather than rules, and what each one is honestly suited to.
One subject, one speaker, a handful of questions taken at the end. A quarterly update, a product explanation, a short briefing. Suits an audience that wants the information and intends to leave, and punishes any padding immediately.
The common shape for a reason: enough room for an argument with evidence, a proper set of takeaways and a real question period. Two speakers fit without either being hurried. Anything that would be rushed at forty minutes is usually an hour of material.
Justified when the subject genuinely needs it: a comparison of options, a case walked through in detail, a question-and-answer period that is the point of the session rather than its leftover. Long enough that the running order has to be visibly structured, or drift shows.
At that length you are no longer running a webinar in the listening sense; you are running a workshop, and the room should be doing something rather than receiving. If the agenda needs three hours, the format is wrong rather than the clock generous.
Build the agenda in chapters before you commit to a duration, and give each chapter two things: a time it should take and a takeaway the audience leaves with. Then add up the chapters, and add the transitions, because the five minutes it takes to move from one subject to the next are the minutes every planner forgets. That total is your honest length, and it will almost always be shorter than the number you had in mind.
If the total is much longer than the hour you wanted, the fix is not to speak faster. Cut a chapter, drop a takeaway, or move something to the slides people receive afterwards. If the total is much shorter than the length you announced, you have discovered the padding before your audience does, which is the cheapest possible moment to find it. Either way the arithmetic is doing the work the rule of thumb could not, and the duration you publish is one the material can actually fill.
On our side this is a setting rather than a rule, and it is worth being precise about that. When you build the session you give it a start time and a session length, and the length is expected to sit somewhere between forty-five minutes and two hours. That range is a thing you fill in and the page displays as a detail so guests know what they are signing up to; it is not a limit we police, and nothing about your running order is checked against it. If the material needs seventy minutes, you write seventy and the agenda has to carry it.
What the page does carry, and what matters more than the headline duration, is the published running order. A room that can see four chapters, their times and their takeaways will stay through ninety minutes, because they know where they are and when the relief arrives. A room looking at the words "approximately one hour" has no such reassurance. So state the length once and spend your effort on the chapters, and hold yourself to them on the night. Ending eight minutes early on a session that was well structured is the fastest way to be invited back.
How it works
Three to five subjects, each with what the audience takes from it. Resist putting a number on anything yet; the aim is to find out what the session actually contains.
Be generous with the movement between chapters and unsentimental with the material. Anything you cannot time without hurrying is a candidate for the slides rather than the hour.
Enter the total as the session length, alongside the start time and the time zone shown as a label. If a room across several zones needs to know, write the second zone out on the page yourself.
The chapters with their times and takeaways are what hold attention. The headline number only sets the expectation; the running order is what keeps it.
Questions
It is the right length for a great many, because an argument with evidence and a question period tends to add up to something near it. It is not a default to defend. Time your chapters and take whatever number falls out, even if it is forty minutes.
It gets better attendance than a long one only if the length is explained. A twenty-five-minute session can look slight next to an hour of someone else's. A clear agenda of three tight chapters reads as respectful of people's time rather than as thin.
Decide in advance and put it in the running order, usually ten to fifteen minutes near the end. Answering as you go turns a structured hour into a conversation nobody is steering, and the subjects later in the agenda are the ones that get cut.
No. The session length is a detail you supply and the page displays, expected between forty-five minutes and two hours. Nothing checks your agenda against it and nothing stops you finishing early. It is there so a guest knows what they are committing to.
Only if you recorded it on your own platform, and only if you choose to send it. After the session the host can hand out their own links for a replay, slides or resources to the people who registered. We store no video of the session.
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Write the chapters, give each a duration and a takeaway, and publish the total the agenda can honestly fill. Ninety minutes is not a rule and forty is not a shortcut.
