3-3-3, 1-3-5, Ivy Lee or Rule of 3: which rule should you use?

The 3-3-3 rule is a simple way to plan a workday: spend about three hours on your most important project, finish three shorter urgent tasks, and handle three maintenance tasks such as email or filing. It is one of four popular priority rules, and the right one depends on how your days are actually built.

The four rules in one table

The Rule of 3

The Rule of 3 comes from J.D. Meier's Agile Results, a practitioner method that applies it to the day, the week, the month and the year. You choose three outcomes you want by the end of the day, and if those three are done, the day counts. Three is a design choice, not a law: research does not name an ideal number of priorities, but three is few enough to remember without looking and enough to make real progress. Our short take is the Rule of 3: why three priorities beat a long list.

The 3-3-3 rule

The 3-3-3 rule gives the day a shape rather than just a number. The three hours go to one project that needs depth: a proposal, a design, a chapter. The three shorter tasks are the urgent items that would otherwise interrupt those hours. The three maintenance tasks keep things running, such as the inbox, invoices or a shared folder that needs tidying. It works best when you can protect one long stretch of time, and it struggles on days full of meetings.

The 1-3-5 rule

The 1-3-5 rule sizes the list instead of capping it: one big task, three medium tasks and five small ones, nine items in all. It suits roles with many small requests, because it admits they exist while still putting one big item first. The risk is that the five small tasks are the most satisfying to tick off, so the big one slips into the afternoon. Do the one first.

The Ivy Lee method

At the end of each workday, write down the six most important things to do tomorrow and rank them. The next day, work on the first until it is finished before moving to the second; anything unfinished moves to the next evening's list. The method is named after Ivy Lee, and the story usually told about how it began in the early 1900s is an anecdote rather than a documented record. What we like about it is the evening ranking: you begin the morning without having to decide anything.

Which one should you use?

• One big project and a lot of upkeep: the 3-3-3 rule.
• Many small requests: the 1-3-5 rule, with the big task done first.
• Mornings lost to deciding what to do: the Ivy Lee method, ranked the evening before.
• Lots started, little finished: the Rule of 3.

You can also combine them. Many people use the Rule of 3 to choose the priorities and the 3-3-3 rule to decide how much of the day each one gets.

What none of them settles: when you start

All four rules decide what goes on the list. None of them says when each item happens, and a priority without a time tends to slide to tomorrow. So whichever rule you pick, give each priority a Start & End Time and decide the exact moment you begin the first one. That is how the Action Day® Method continues after the Rule of 3, TO-DO → TIMEBOX → DO → DONE™, and how it works sets out all four steps. Writing that starting moment is covered in if-then planning.

Put it on paper

The Timeboxing® Daily Planner starts each day with To-do list 1, a box for the three most important tasks with the time each will take to complete, next to an hourly schedule where those tasks get their timeboxes. Whichever rule you follow, the top three go there first. The rest of your list stays below as the backlog, ready to supply tomorrow's three.