Sankey Cash Flow Diagram
A flow diagram where the width of each stream is proportional to the money moving through it.
Sankey diagrams encode quantity as width. Money enters on one side, divides into categories, and arrives at destinations on the other, with every branch sized in proportion to the amount flowing through it. Matthew Sankey drew the first one in 1898 to show energy losses in a steam engine, and the form still suits anything that divides and subdivides.
The advantage over a pie chart is that it shows the division as well as the shares: a pie can say food was 12% of spending, while a Sankey shows income dividing into food, housing and the rest, with whatever is left over as a branch of its own. Promi's version starts from what lands in your accounts, so tax withheld from a paycheck never enters it, and tax paid or refunded through an account nets against income.
Comparison is what the eye does well here. Two streams of similar width are similar amounts, and that reads instantly in a way two numbers in a table do not, particularly when the categories are ones nobody thinks to compare.
Worked through
$5,625 of take-home a month, split
What lands in the accounts after withholding, dividing three ways, each branch sized by amount.
- Take-home
- $5,625
- Housing
- $2,100
- Everything else
- $2,025
- Net Savings
- $1,500
Housing takes 37% of what arrived, and Net Savings is the $1,500 left once every category is counted.
Where this lives in Promi
Cash Flow page. Income by category, then spending by category beside a Net Savings branch, then the accounts the money left from.
Related in Cash Flow & Runway
See your own sankey cash flow diagram
Promi computes this from your linked accounts, with the definition one click from the number.
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