The 1-3-5 Rule
The 1-3-5 rule is a way to plan a day: assume you can finish one big task, three medium tasks and five small tasks, and write down only those nine.
The numbers matter less than the idea behind them. A day has room for a fixed amount of work, so you choose that work before the day starts, instead of letting a long list and an inbox choose for you. This page explains the rule, how to size the tasks, an example day, and when a shorter list works better.
Where the rule comes from
The 1-3-5 rule is usually credited to Alexandra Cavoulacos, a co-founder of the career site The Muse. She describes it in The New Rules of Work, the book she wrote with Kathryn Minshew. Her advice is to write the next day's 1-3-5 list before you leave work, so the morning starts with the choices already made.
How the 1-3-5 rule works
- Pick one big task. The one piece of work that would make the day a good day if it were the only thing you finished.
- Pick three medium tasks. Work that needs real attention but not a whole morning.
- Pick five small tasks. Quick jobs: a reply, a booking, a payment, a short call.
- Write the list the evening before. Nine items, no more. Anything else waits for another day.
- When something urgent arrives, it takes a slot. An unplanned task does not go on top of the nine. It replaces one of them, and the replaced task moves to tomorrow.
How big is big? Sizing the tasks
The rule works only if the sizes are accurate. Size each task by the time and focus it needs, not by how important it feels. A rule of thumb that we use:
- Big: a few hours of focused work. Writing a proposal, building a feature, preparing a presentation.
- Medium: about an hour. Reviewing a document, a planning meeting, fixing a known problem.
- Small: fifteen minutes or less. Sending an invoice, booking an appointment, answering one message.
If the big task cannot fit in one day, it is a project, not a task. Write down the part of it that you can finish today.
An example
Say you run a small online shop. On Monday evening you write Tuesday's list:
1 big
- Write the product pages for the new winter collection
3 medium
- Photograph the five new scarves
- Answer the wholesale enquiry with prices
- Plan this week's newsletter
5 small
- Pay the packaging supplier
- Reply to the customer who asked about sizes
- Print today's shipping labels
- Renew the domain name
- Book the accountant for next week
On Tuesday at eleven, a customer reports a broken order. That fix takes the place of the newsletter plan, which moves to Wednesday. The day still has a clear shape, and nothing was added on top.
Common mistakes
Nine big tasks in disguise
"Finish the website" written as a medium task makes the list impossible. If a task does not fit its size, split it.
Adding a tenth item
The limit is what makes the list work. When a new task arrives, something on the list moves to another day.
Starting with the small tasks
Five quick wins feel productive, and they can fill the whole morning. Start the big task first, while you have the most energy, and use the small ones for the gaps between meetings.
1-3-5, Ivy Lee, or three tasks?
The 1-3-5 rule is one of several methods with the same core: a short list, chosen in advance, with a hard limit.
| Method | Tasks per day | How tasks are chosen |
|---|---|---|
| 1-3-5 rule | 9 | By size: one big, three medium, five small |
| Ivy Lee method | 6 | By importance, in a fixed order, one at a time |
| 3 Things | 3 | The three that matter most today |
Nine tasks suit a day with long stretches of free time and many small jobs. On a day full of meetings, messages and interruptions, nine is often too many, and a list you never finish teaches you to stop writing it. Three tasks keep the main idea of the 1-3-5 rule, the one big task at the top, and drop the rest. Use the number that you can finish most days.
How 3 Things helps with a short daily list
3 Things is a daily planner built on the hard limit. It works like this:
- Three slots per day. Today shows three slots and there is no fourth slot. Put your big task in the first one.
- Unfinished tasks are never lost. Anything you do not finish stays in your queue and moves to the next day that has a free slot.
- A streak of finished days. Your streak grows on each day you finish all three tasks.
- A daily reminder. Turn on reminders in the Me tab and pick a time, and the app reminds you to plan your day.
- Plan tomorrow the evening before. With the Pro subscription, the Future tab lets you fill Tomorrow and the Day after, three tasks each. Planning today is free.
More about reminders and streaks is in the FAQ.
Try a three-task day with 3 Things
Free to download. Three slots on Today, nothing more.
Frequently asked questions
Who created the 1-3-5 rule?
It is usually credited to Alexandra Cavoulacos, a co-founder of the career site The Muse. She describes it in the book The New Rules of Work, written with Kathryn Minshew.
What counts as a big, medium or small task?
Size them by time, not by importance. A rule of thumb: the big task takes a few hours of focus, a medium task takes about an hour, and a small task takes fifteen minutes or less. Adjust the sizes to your own day.
What if I do not finish all nine tasks?
Move what is left to tomorrow's list. If you miss the list most days, it is too big for your days. Make the big task smaller, or drop to fewer tasks.
Can I use the 1-3-5 rule with three tasks?
Yes. Three tasks is the same idea with fewer slots: one task that matters most and two more. The 3 Things app uses three slots, because three is a list you can finish on a day full of interruptions.
Should I plan the list in the morning or the evening before?
The evening before works best for most people. You know what is still open, and the next morning starts with a decision already made.