Back of the Napkin

Back of the Napkin

Back of the NapkinThere is no question that I live in a world of numbers.  I am constantly making calculations in my head throughout the day.  Whether it is how many miles my car is getting per charge, number of page views on my blog per minute, or even measuring out the food to drink ratio at a meal, my mind is always churning.  Strangely enough, however, I am by no means a spread sheet guru.  Unlike many in this community. I prefer the financial forest from the trees.  The result is that although always calculating, my work product is often an ephemeral, rounded, big picture sort of view-point.  I am a back of the napkin kind of guy.  I prefer to make decisions on the fly without intense mathematical modeling, spreadsheets, nor calculators.

I suppose there are some downsides to my methodology.  I live and die by my own quick mathematical acuity.  There is no question that downstream, rounding errors can sometimes have big consequences.  Yet I’ve found this habit has generally served me well.

I Don’t Need a Budget (IDNAB)

I am a tracking fool.  Not as in I do it all the time and I’m good at it.  More like, I stumble and splutter and get frustrated.  It’s not that I don’t find the information useful.  It’s just that everything seems to fall apart.  I loved Personal Capital and Mint.  For about a month.  And then my ten trillion different accounts continuously had trouble connecting.  I was changing the passwords everyday and spending thirty minutes at log in rescuing my accounts.  The headache was not worth the gained information.  instead, I work with a non budget.

My naturally frugal habits pave the way for my back of the napkin lifestyle .   I know how much comes in every month through paychecks, and I know roughly what goes out through credit card bills.  Add a few extras here and there and poof.  My own little  semi accurate spreadsheet laid out nicely in my head.

 

Back of the Napkin

Net Worth, Meh!

My net worth calculations are no different.  I love to see bloggers out there month by month tracking net worth down to the penny.  I tip my hat to them.  I don’t have the fortitude.  Flummoxed by market valuations, property variances, and momentary cash flow needs, any number I produced would change by the hour.

That doesn’t mean I am not aware of my current asset and cash holdings.  I can look at the market any given day and give a fairly precise number with a little mental gymnastics.

As I get older, however, I am seeing that such calculations are less fruitful than I once thought.  Of course, having a knowledge of starting point and end goal is important in the journey to FI, but once there, the fluctuations are less important.  Especially if you have market apathy like me.

I prefer my back of the napkin calculation.  Less accurate but more relevant to my day-to-day life.

Rounding Errors

There is no question that while my methods are fast and easy, they are definitely less precise.  If it can’t be rounded without damaging the fidelity of the calculation, then the back of the napkin is not the way to go.  So once and awhile I do pull out the old calculator or even revert to a spreadsheet.

But it’s rare.

Back of the NapkinThe majority of math used in personal finance, as well as life ,can be done in one’s head.  Don’t believe me?  Try it some time.

Final Thoughts

Although constantly playing with numbers in my daily life, I have found that when it comes to financial independence, back of the napkin calculations are good enough.  There are always times when precision is necessary, but for the rest, I find doing the math on the fly much more easy and enjoyable.

I mean who likes sitting hunched over a spreadsheet with calculator in hand perusing the detailed minutia of daily spending and saving habits?

Who wants to be constantly playing with retirement calculators adjusting variables to see how to shave a few months off the big projected date?

Umm, Ok, like seventy-five percent of the people reading this blog.

I guess there is nothing wrong with that method either.

 

Doc G

A doctor who discovered the FI community but still struggling with RE.

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17 Responses

  1. I’m definitely in the unofficial napkin group. Any note then that and I’ve found my own biases creep in. It essentially protects me from myself.

  2. Xrayvsn says:

    There definitely is a certain point when having a budget will have less of an impact on your finances. I never budgeted myself and it probably hurt me early on (I would have likely become more debt averse in beginning if I could actually see what was leaving my house because of debt and interest) but at my current state I take the financial forest over the trees approach too and it serves me well. Especially if you naturally save a lot anyway. A general trend of where your networth is heading is good enough for me

  3. Dr linus says:

    I think you start with a physical napkin or spreadsheet and eventually move on to the a less physical more mental one as you become an expert. Kinda like those reference books you carry around like a Med student and eventually your pockets are empty and the knowledge is in the brain.

    Here is a link to my real estate napkin
    https://www.dadsmakingcents.com/rule-of-thumb-the-real-estate-deal-napkin/

  4. Dr. McFrugal says:

    I have a similar problem with Personal Capital since it has a problem connecting with a few of my obscure accounts. But I know how much is in those accounts, so I don’t sweat it. Plus the amounts that are in these accounts are a small fraction of my net worth. So I still check Personal Capital every now and then because I’m in my rapid accumulation phase and it is so fun to track progress.

  5. Over the years as we have paid off all of our debts and saved a substantial amount of “extra” cash, we have selected things such as home insurance with lower premiums and high deductibles. Moves like that make it where our bills are less steady. No problem. I actually don’t see how people budget really. The reality of our spending and net worth has been more like watching the stock market. Lots of ups and downs but a steady climb over time. Perfect for the back of napkins. What happened to envelopes? I guess the end of snail mail made us move to napkins!

    • Doc G says:

      You can still say back of the envelope. But your point about snail mail is probably true. I agree with you on budgets.

  6. Gasem says:

    I’m much more quantitative. I use Mint several times a month to track spending. I wish I’d discovered it 10 years ago, amazing money saver. I keep a running spreadsheet of expenses, which has lead to an accurate method of splurge spending during retirement. The Mint spreadsheet transaction takes less than 5 minutes per instance. I use a program to track my investment portfolio which is very granular. My portfolio is pretty complicated and I can ask a question and pretty well come up with an answer with this program. I also use personal capital since it has efficient frontier calculations built in and asset allocation built in both of which are very good. It also has Monte Carlo which is a great check on your alternative projection. If projections don’t match something bears looking into. I use back of the napkin only for farting around. If you want to dig a hole why use a teaspoon?

    • Doc G says:

      If your hole is built and perfect, why keep remeasuring? Maybe just eye it from time to time?

      • Gasem says:

        The software remeasures it I just watch it. I’m in the middle of spending down not accumulating so my life is market dependent and W2 independent. My retirement is not market dependent as I’m over subscribed but the moving parts of taxes etc are not trivial. Waiting a year to start conversion saved me a lot in conversion taxes. I’m Roth converting a couple million over several years which means TAXES need to be paid and generating that money requires efficient analysis, and the conversion needs to be reinvested. Accumulation is the easy part.

  7. In common language this is called “close enough for government work” 🙂

  8. Kate says:

    BLASPHEMY! (just kidding 😉
    I do love my budget, but it is more of a loose estimate than anything. I still do sit down with YNAB a few days a week though! Just tracking it helps keep me aware of the ins and outs

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