Johnny.Decimal is a system to organise your stuffyour digital life
It’s designed to help you find things quickly, with more confidence, and less stress.
In real life, if you stored your stuff in piles of badly-labelled boxes you’d never find anything again.
If you put those boxes in boxes, in boxes, you’d never know which box to open to find the next box. It would be chaos.
But I just described how you save your computer files.

Let’s get organised
Imagine your computer as a physical storage space. We can’t put everything on the floor, so we buy some shelves.
If we had a limitless number of shelves, we wouldn’t know which one to look on when we wanted to find something. So we get ten shelves.
We decide to dedicate each shelf to an area of our life.
The first will contain everything to do with our life administration
. The second is for our home business
, and the third covers our music
hobby.
(Notice that we don’t try to use all ten shelves. There’s room to grow.)

Each shelf has space for ten boxes. So we need to decide how to categorise the things that we’re going to store.
In life administration
we decide on a box each for finance
, health
, house
, education
, technology
, and travel
.

Your categories might be different. Maybe you own a car, or have kids. You design your system to suit your life.
Our boxes have space for a number, so we label everything neatly.

(I’ll explain on a later page why the first box isn’t number 01
or 10
.)
File your stuff in folders
Now we have categorised boxes. Let’s organise our travel insurance.
We put our documents in folders, and store those folders in the boxes.

Every folder gets a number. This helps us keep track of them. We start at 01
, and give each new folder the next available number.
So the first item in our 16 Travel
category might be a trip we took: 16.01 Singapore, Jun 2022
.
The next item we file is 16.02 Travel insurance
.

And this is exactly how we structure our file system.

The Johnny.Decimal ID
Each of our items now has a number. They’re always two digits, a decimal, and two digits.
16.02
22.06
31.17
This number is really useful.
It provides structure
The Johnny.Decimal ID tells us exactly where a thing is. The numbers before the decimal are the item’s category, and they define the structure of your system.
At a glance, you know what sort of thing the item contains. You’ll be astonished at how many of your category numbers you remember.
They’re easy to communicate
They’re short, memorable, and can be spoken out loud. Say it like “sixteen oh-two” or “thirty-one dot seventeen”.
This is really handy when you want to tell someone (including your future self) where a thing is.
Things stay where they are
The alphabet is a great way to organise a dictionary, but it’s a terrible way to organise your files.
Alphabetically, things move around as you create other things. So you never get a chance to develop muscle memory: you’re always hunting for what you want.
Numbers solve this problem. In our example above, the categories in area 10-19
aren’t alphabetical. They sort by the category number.
And so when we create a new category, 17 Aardvark collection
, nothing moves.
It imposes limits
Your computer will let you create any number of folders, anywhere you want.
It turns out this is a terrible idea.
The ‘no more than ten’ concept is at the heart of Johnny.Decimal.
When you start looking for a thing, you have no more than ten areas to choose from. Your thing must be in one of them: select the most appropriate and now you can ignore the others.
Now you have no more than ten categories to choose from. Repeat the process.
We’ve arrived in a folder with no more than one hundred IDs. If you created your thing recently, it’ll be one of the higher numbers. If you created it a while ago, it’ll be one of the lower numbers.
And things that you created together, stick together. The alphabet isn’t around to ruin the party.
Is this for home or work?
Anywhere you want. The concepts are the same no matter what you want to organise.
I like it! What next?
The rest of this website contains a detailed description of the system.
I’ve also created a comprehensive, start-to-finish guide to setting up your own Johnny.Decimal system.
And if you ever need help there’s a forum, a Discord server, or you can just ask me.
Click the link below to learn more about areas and categories. And welcome to the Johnny.Decimal family.