The 1-3-5 rule is a way to cap a daily to-do list: each day you plan one big task, three medium tasks and five small tasks, nine items in total, and nothing else goes on the list. It comes from The Muse, which credits its co-founder Alex Cavoulacos. It works only if the nine tasks fit the hours you really have, which most guides never check.
Key Takeaways
- The cap is the point: nine tasks, one big, three medium, five small. The exact numbers are a default you can adjust.
- With the size ranges most guides give, nine tasks add up to anywhere from about 4 to more than 8 hours. A full-time weekday holds about 8.5 hours of all work.
- A 2-2-1 budget (2 hours big, 2 hours medium, 1 hour small) leaves room for meetings, messages and overruns.
- For ADHD, start with 1-1-3, time every item and pad your estimates. Nobody has tested the rule as an ADHD strategy.
What is the 1-3-5 rule?
The 1-3-5 rule is a daily planning limit. Before the day starts, you choose one big task, three medium tasks and five small tasks, and that list of nine is your whole plan. Anything else waits for another day or goes in a backlog. The idea is to accept that a day holds a finite amount of work and to make the most important item part of it on purpose.
| Tier | How many | Common size range | Budget that fits a real day | Example |
|---|---|---|---|---|
| Big | 1 | 2 to 4 hours | Up to 2 hours (one deep block) | Draft the client case study |
| Medium | 3 | 30 to 60 minutes each | 2 hours for all three | Build slides for Thursday’s call |
| Small | 5 | 5 to 20 minutes each | 1 hour for all five | Approve an invoice |
| Total | 9 | About 4 to 8+ hours | 5 hours of task time | Leaves time for meetings and messages |
The size ranges come from the guides ranking for this term: Todoist puts big tasks at 2 to 4 hours, medium at 30 to 60 minutes and small at 5 to 15 minutes; ActiveCollab gives small tasks up to 15 to 20 minutes. The budget column is ours, and the next sections show why.
Where did the 1-3-5 rule come from?
It comes from The Muse, the careers site. Its post “A Better To-Do List: The 1-3-5 Rule” says the editors picked it up from tips shared by their founder and president, Alex Cavoulacos. The live page shows an update date of June 2020, but the Internet Archive holds a copy from March 1, 2014, so the rule has been in circulation for more than a decade.
The original is short. It says to “accept that you can reasonably get one big thing, three medium things, and five small things done” and to keep the list to those nine. It also builds in two escape hatches that later versions drop: if much of your day is meetings, cut the number of items, and if your job throws unexpected work at you, leave some slots blank.
Todoist says Cavoulacos also covers it in The New Rules of Work, her 2017 book with Kathryn Minshew; we could not verify the passage, so the Muse post stays the primary source.
Why does capping your list at nine tasks help?
A capped list forces the hard choice in the morning instead of at 4 p.m., and it gives you a list you can finish. No study has tested this rule directly. The support comes from wider research on planning: people underestimate how long their own tasks take, and writing a concrete plan for an unfinished goal reduces how much it intrudes on other work.
In the planning-fallacy studies by Buehler, Griffin and Ross (1994), students predicted they would finish their honors thesis in 33.9 days on average. They took 55.5 days, and only 29.7% finished by their own best estimate. An uncapped to-do list is the same optimism applied to a single day.
Masicampo and Baumeister (2011) found that unfinished goals caused intrusive thoughts and worse performance on unrelated tasks, and that letting people write a specific plan for those goals removed the effect. A short list where each item has a slot is that kind of plan. A list of 30 items with no slots is not.
Do nine tasks really fit in one workday?
Nine tasks fit only if you size them with a clock. Using Todoist’s own ranges, a 1-3-5 list totals between 3 hours 55 minutes and 8 hours 15 minutes of task time. The Bureau of Labor Statistics found that full-time workers put in 8.5 hours on the weekdays they worked in 2025, and that figure covers meetings and email too. The top of the range cannot fit once meetings are counted.
The arithmetic, with Todoist’s ranges:
- Big: 2 to 4 hours.
- Medium: 3 x 30 to 60 minutes = 1.5 to 3 hours.
- Small: 5 x 5 to 15 minutes = 25 to 75 minutes.
- Total: 3 hours 55 minutes to 8 hours 15 minutes.
Microsoft’s 2025 Work Trend Index found the average worker gets 117 emails and 153 Teams messages a weekday and is interrupted every 2 minutes by a meeting, email or notification. Half of all meetings fall between 9 and 11 a.m. and 1 and 3 p.m., the same windows most people would pick for a big task.
Say meetings take 1.5 hours and messages another hour. That leaves about 6 hours for the list. The midpoint of the ranges (3 hours, plus 2 hours 15 minutes, plus 50 minutes) already needs 6 hours 5 minutes with zero overruns, and the planning-fallacy research says there will be overruns.
This is where we part ways with most of page one. Hubstaff frames the nine tasks as a way to limit your workload. It does not add up the hours, and neither do most of the other guides on page one. The Muse original was more careful than its copies: telling readers with meeting-heavy days to cut items is the arithmetic problem stated in one sentence.
How do you size big, medium and small tasks?
Size each task by the minutes it will take, then check the tiers against a fixed budget. We use the 2-2-1 budget: the big task gets up to 2 hours, the three medium tasks share 2 hours, and the five small tasks share 1 hour. That is 5 hours of planned task time, which leaves room in an 8-hour day for meetings, messages and things going wrong.
Put a number of minutes on every task first; “medium” means nothing until it has one. Then check three things:
- A big task over 2 hours gets split. “Write the annual plan” is a project; “draft the budget section” is a big task.
- Mediums over 2 hours in total lose one. Three 60-minute mediums are a second big task in disguise.
- Anything over 15 minutes is not small. Five 20-minute “small” tasks make a 100-minute block.
Then track real times for a week and size the next week from them. A timeboxing practice helps here, because every task already has a start and an end.
If your list starts as a long backlog, begin with a brain dump turned into a plan, then pick the nine.
What does a 1-3-5 day look like with real times?
Here is a worked example for a content marketer with an 8-hour day (9:00 to 5:30 with a 30-minute lunch), a 15-minute standup, a 1-hour client call and about 45 minutes of email and chat. That leaves 6 hours for the list. Sized with the 2-2-1 budget, the nine tasks come to 4 hours 55 minutes, which leaves a buffer of about an hour.
| Tier | Task | Estimate |
|---|---|---|
| Big | Write the first draft of the 2,000-word customer case study | 120 min |
| Medium | Review the landing page mockups and leave comments | 40 min |
| Medium | Build slides for Thursday’s client call | 45 min |
| Medium | Edit the freelance writer’s blog post | 35 min |
| Small | Approve the photographer’s invoice | 10 min |
| Small | Reply to the agency about the shoot date | 10 min |
| Small | Book a room for Friday’s workshop | 5 min |
| Small | Update the content calendar | 15 min |
| Small | Send the weekly numbers to the manager | 15 min |
| Total | 4 h 55 min |
The case study goes first, 9:15 to 11:15, before the meeting windows fill. Two small tasks sit between the standup and the client call, where a 15-minute gap is too short for anything else. The mediums go in the afternoon and the remaining small tasks close the day.
Now the overrun check. If every task runs 20% over, 4 hours 55 minutes becomes about 5 hours 54 minutes, which uses almost all of the buffer. The day still holds. Size the same nine tasks at the top of the common ranges and the list alone is 8 hours 15 minutes, longer than the whole day before a single meeting.
When a day goes wrong, cut from the bottom: small tasks move to tomorrow first, then a medium. Protect the big one.
What is the 1-3-5 rule for ADHD?
There is no separate ADHD version of the 1-3-5 rule; people with ADHD use the same one big, three medium, five small list. It has not been tested as an ADHD strategy and it does not treat ADHD. What helps is adapting it: fewer items to start, a timer on every task, and estimates padded for the timing difficulties research links to ADHD.
The NHS lists “finding it hard to organise your time” and “finding it hard to follow instructions or finish tasks” among the signs of ADHD in adults. A 2022 meta-analysis of 55 studies found “a broad range of timing deficits in persons with ADHD,” including less accurate time estimation, and a 2023 review of adult studies describes the daily cost as trouble with punctuality and planning. Lab studies suggest a plan built on time estimates is where that shows up.
Adjustments that follow from this:
- Earn the nine. Start with a 1-1-3 list. When you finish it on four days out of five, move to 1-2-4, then to the full 1-3-5. A list you finish teaches more than one you abandon at noon.
- Time every item, including the small ones. A 10-minute task with a visible countdown has an end; without one it can quietly become 40 minutes.
- Double your first estimates for a week, record the actual times, and size the next week from those.
- Use a small task as a warm-up if starting is the problem. Most guides say to do the big task first. If a cold start leads to an hour of avoidance, a 10-minute win first is the better trade. Our piece on why ADHD procrastination happens covers that starting problem.
If trouble with time and tasks is affecting your work, studies or relationships, the NHS advice is to see a GP (in the US, a primary care doctor) about what support is available. A planning method can sit alongside that support but should not replace it. The free time blindness quiz gives you something concrete to bring to that conversation; it is a screening aid with no diagnostic weight.
What are the alternatives to the 1-3-5 method?
The closest alternatives are the 1-2-3 variant, the Ivy Lee method and the rule of three. All of them cap the day’s list; they differ in how many items they allow and whether items are sized or ranked. Pick by the kind of day you are planning.
The 1-2-3 variant. One big, two medium, three small: six items with the same shape. It is the fallback when your 1-3-5 days keep failing the arithmetic.
The Ivy Lee method. At the end of each workday, write down the six most important things for tomorrow, rank them, and work through them strictly in order, carrying unfinished items to the next list. James Clear traces it to 1918 and Ivy Lee’s work with Charles M. Schwab at Bethlehem Steel. It ranks instead of sizing; see the Ivy Lee method in our glossary.
The rule of three. Name the three outcomes you must produce today and treat everything else as optional. It is the strictest of the four and suits meeting-heavy days. Our glossary entry on the rule of three explains how to choose outcomes rather than activities.
If you want the big task done first thing, eat the frog pairs with any of these. For ranking systems such as Eisenhower and MoSCoW, see our comparison of task prioritization frameworks.
When should you not use the 1-3-5 method?
Skip it on days that do not have room for nine tasks or do not break into nine pieces: meeting-heavy days, reactive roles where most work arrives during the day, and deep-work days given to one long task. On those days a shorter list, a single protected block or a fully timeboxed calendar will serve you better than forcing nine items.
The clearest signal is meetings. With more than 3 hours of them, 8 hours minus 3 of meetings and 1 of messages leaves 4, less than the 5-hour budget, so drop to 1-2-3 or the rule of three, as the Muse post suggested. On support or on-call days, where most work arrives as tickets, leave slots blank or plan only the big task. A single six-hour job, such as writing a chapter, needs one protected block rather than nine items. And in a week with one fixed deadline, plan backward from the deliverable and let each day’s big task be its next piece.
How to run a 1-3-5 day in FocusBox
FocusBox is a productivity app for planning a day with AI to-do lists, timers and timeboxing, designed with ADHD in mind. It has no special 1-3-5 mode, but it has a ready-made template: The 1-3-5 Rule Rhythm structures the day into one big, three medium and five small tasks, and you can edit it and load it into your day.
Every task in FocusBox has a name and a duration, and task design lets you increase or decrease each timer and move a task to the top by priority. That covers the 2-2-1 sizing step: give the big task 120 minutes and each small task 10, and the totals are visible before the day starts. If the big task is still vague, the AI To-Do List Generator turns a plain-language description into editable tasks and subtasks, which helps cut a project down to a big task that fits in 2 hours.
One limit to know: the free plan covers 5 tasks, so a 1-1-3 starter list fits but a full nine-item list needs Premium, which lists unlimited tasks (focusbox.io/pricing, October 2026). Reports then show what you completed and where your time went, which is the record you need to correct next week’s estimates.
Frequently Asked Questions
What is the 1-3-5 rule in time management?
It is a daily to-do list limit: one big task, three medium tasks and five small tasks, nine in total, chosen before the day starts. For it to work, the nine estimates need to add up to less than the free time in your day.
Who created the 1-3-5 rule?
The Muse, the careers site, published it and credited its co-founder Alex Cavoulacos. An Internet Archive copy shows the post was online by March 2014.
How many hours does a 1-3-5 list take?
With the ranges common in guides, anywhere from about 4 to over 8 hours. A 2-2-1 budget (2 hours big, 2 medium, 1 small) keeps it at 5 hours, which fits an 8-hour workday with meetings.
What if I don’t finish all nine tasks?
Move what is left to tomorrow and make the next list smaller or the tasks shorter. Finishing seven of nine most days means the sizes are slightly off; finishing three means the list is too long.
Is the 1-3-5 method good for ADHD?
It has not been studied for ADHD. Many people adapt it by starting with fewer items, timing every task and padding estimates, because research links ADHD to difficulties with time estimation. If time and task problems affect your work or life, talk to a doctor.
Sources
- A Better To-Do List: The 1-3-5 Rule (The Muse, accessed October 2026)
- Internet Archive capture of the Muse post, March 1, 2014 (web.archive.org, accessed October 2026)
- American Time Use Survey, 2025 results (Bureau of Labor Statistics, accessed October 2026)
- Breaking down the infinite workday (Microsoft Work Trend Index, June 2025, accessed October 2026)
- Buehler, Griffin and Ross. Exploring the “planning fallacy”: Why people underestimate their task completion times (Journal of Personality and Social Psychology, 1994)
- Masicampo and Baumeister. Consider it done! Plan making can eliminate the cognitive effects of unfulfilled goals (Journal of Personality and Social Psychology, 2011)
- ADHD in adults: symptoms (NHS, accessed October 2026)
- Marx et al. Meta-analysis: Altered Perceptual Timing Abilities in ADHD (Journal of the American Academy of Child and Adolescent Psychiatry, 2022)
- Mette. Time Perception in Adult ADHD: Findings from a Decade, A Review (International Journal of Environmental Research and Public Health, 2023)
- The Ivy Lee Method (James Clear, accessed October 2026)
- How to Plan Your Day with the 1-3-5 Method (todoist.com, October 2026)
- 1-3-5 rule: how and when to use it (activecollab.com, October 2026)
- 1-3-5 Rule for Productivity: Strategies and Examples (hubstaff.com, October 2026)
- Make a Better To-Do List With the 1-3-5 Method (lifehacker.com, October 2026)
