Tracking Cash-Flow with Sankey Diagrams

There's been a trend on the subreddit Data is Beautiful to display one's monthly cash flow as a Sankey diagram. There were a few days last week where the whole sub was covered in these cash-flow diagrams from different locations, and it was enlightening.

The Sankey visualization helps show the transformation of inputs into outputs, and so it's a terrific way to see how income transforms into expenses. You can build your own here:

SankeyMATIC

I did my first draft of one. It's not for my monthly spending but everything we've spent so far this year:

I'll have to update it once the year is over, and maybe I'll average things out to figure out some kind of monthly flow. As it is, we face expected but one-off large expenses at various points in the year, so I tend to think of them as yearly expenses, and that doesn't jive with a monthly cash flow chart.

A few easy takeaways:

• The "Other Spending" category holds a lot of stuff, but the main sub-categories within it have drastically different weights. Thankfully, the "Household" (those one-off expenses that my wife and I agree to purchase, such as furniture) and "Dentist" categories should substantially drop after this year. As long as we don't spend that money elsewhere that is...
• The smaller expenses are really very small. Compared to the rent, the "Gym" expense is peanuts. I think we should be careful with smaller expenses, but it really does help visualize just how important getting the big things right really is.
• The BLOW categories are surprisingly large. They also contain a lot of different kinds of expenses, and I'm half tempted to break BLOW down into subcategories just to see where that money is going. BLOW, if you'll recall, is sort of our allowances to ourselves to spend on whatever without needing permission from the other spouse. Restaurant bills fall under BLOW, which is why they're not broken out.
• Not having a car saves us a lot. I'd love to lower our "Transportation" costs even further, but, man, this is so much better than when I was driving around in the USA.
• On my next draft, I'll need to add in my automatic withholdings from my paycheck. I'd like to see how that adds up. As is, you're seeing Job 1 as post withholding, and Job 2 as pre-tax. The "German Taxes" and "Rentenversicherung" are only for our estimated tax pre-payments and my wife's payments to the social security system since she's freelance.