How to make a simple decision tree
A simple decision tree is the options in front of you and what could follow from each, with no numbers at all. It takes five minutes and it is often all a decision needs. This guide makes one in five steps with a free simple decision tree maker, using an office move as the example, then shows what happens when you add numbers.
Published 2026-09-29. By the DecisionBranch team.
What a simple decision tree is
A map of a choice: the question at the root, one branch per option, what could happen after each, and where each path ends. No chances or values, so anyone can read it and nobody argues about the numbers.
It is the fastest way to get a decision out of your head and in front of other people. Laying the paths side by side shows which options you have not thought through, which outcomes you are worried about, and where you need more information. Many decisions are settled at this point.
Step 1: write the question
One line, phrased as the choice. If it will not fit on one line, you have two decisions.
Should we move to a bigger office?
Name the choice, not the goal. Should we move to a bigger office? is a decision; How do we fit everyone in? is still a brainstorm.
Step 2: list the options
One branch per option, indented under the question. Include waiting or doing nothing when it is a real option; it often is.
Should we move to a bigger office? Move now Wait six months Go hybrid
Step 3: add what could happen next
Under each option, the two or three ways it could play out. Keep them different enough that you would act differently in each.
Should we move to a bigger office?
Move now
The team keeps growing
Growth slows
Wait six months
The team keeps growing
Growth slows
Go hybrid
People like it
People don'tHere the thing nobody controls is whether the team keeps growing. For the hybrid option it is whether people like working that way. Two outcomes per option is plenty for a first pass.
Step 4: end every path
Finish each path with where it leaves you: an action or a result. Add a short note after a # where a path needs explaining.
Should we move to a bigger office?
Move now
The team keeps growing
Room to hire without a squeeze
Growth slows
Sublet the spare desks # check the lease allows it
Wait six months
The team keeps growing
Crowded until the move # hot-desk in the meantime
Growth slows
Stay put and save the rent
Go hybrid
People like it
Keep the current office
People don't
Revisit the move next yearRead across the endings. Crowded until the move is the one people will feel; Sublet the spare desks depends on the lease. That is already a useful conversation, and it is exactly where you would go and check.
Step 5: walk it through and share it
Step through the tree one question at a time to check every path makes sense, then share the link or embed it where the decision is being discussed.
In DecisionBranch a simple tree has a Walk through button: it asks the question, you pick an answer, and it moves to the next. The same walk-through works in an embed on your own site, which makes a simple tree a good fit for guides and policies as well as one-off decisions. Colours and fonts work the same as on any tree.
When to add numbers
Add numbers when the options are close and money or odds are involved. Give each branch a chance and each ending a value, and the tree works out the best option: here Move now, worth 62,000 on average, 4,000 ahead of Wait six months.
This is the same office tree with a chance on each outcome, a cost on the options that cost money, and a value on each ending. Nothing else changed.
# Two-year view, in USD. Values are what each ending is worth to the business.
Should we move to a bigger office?
Move now (cost 40000)
The team keeps growing (p 0.6): 150000
Growth slows (p 0.4): 30000
Wait six months (cost 20000)
The team keeps growing (p 0.6): 90000
Growth slows (p 0.4): 60000
Go hybrid
People like it (p 0.5): 70000
People don't (p 0.5): 10000In the editor you don't have to switch modes: type a value on any ending and the tree starts showing the best option straight away. From there you can see what would change the answer; the full decision tree guide walks through that step by step.