MS ZiYou - Net Worth Spreadsheet

10 Insights from a net worth spreadsheet

As a self-confessed finance geek, I am happy to admit I religiously keep a net worth spreadsheet. This is an OpenOffice (cause I’m frugal) spreadsheet that I use to track my financial position each month. As I was preparing July’s net worth updates for you I realised there are many insights contained in the spreadsheet itself.

I always encourage people to review spreadsheets holistically. For example, at work, you can tell a lot when inheriting a predecessors’ spreadsheets. You can see the changes and evolutions over time and where quick changes were made. KPIs and metrics come in and out of fashion depending on business priorities.

Hence I’ve been taking this approach with my personal net worth spreadsheet. In addition to the actual numbers in my bank and that I owe, I can see my own financial evaluation and priorities shifting gradually. My spreadsheet is now over 6 years old, and here are some of the insights I have gleaned from a review of the past.

1 – I document the good times

Whether it’s a conscious decision or subconscious, this spreadsheet only tracks the best times of my financial life.

Ms ZiYou Money

I only started this net worth spreadsheet once I started earning six figures. So it’s interesting to reflect on why that was? Did I feel the need to steward my income better now there was more? Was financial prudence linked to the amount of money?

By not tracking where I was in my low earning twenties, was I ashamed of my financial progress? Why did I never consider getting the numbers together? I don’t have the answer to these questions now, but I am pondering them in the background to try and understand my rationale.

2 – My financial evolution is laid bare

For me, the most interesting nugget is how my priorities have shifted. From the first evolution of the spreadsheet, I only cared about my net worth and the % LTV (loan to value – the outstanding mortgage divided by property value) on my mortgage. I noted it, saved the spreadsheet then got on with life. And I just automated overpayments into my mortgage with my excess cash.

Financial evolution

Once I got my mortgage down to 60% LTV (and hence lower mortgage rates) by overpaying my focus moved. Instead, I started to get more comfortable investing and bought low-cost index funds. I also moved a small share portfolio ~£1.5k into index funds. And I slowly began moving my cash ISAs into stocks and shares ISAs, one by one.

When this started I cared about net worth, and nowadays most focus is gone from my net worth – my FIRE fund (net worth minus house equity) has superseded it. Today I’m focused on getting to financial independence in the next few years and monitoring this number much closer than net worth.

3 – Targets are good and bad

I’ve found setting myself net worth and FIRE fund targets to be both a curse and genius at the same time. I have tried both approaches – with and without targets. The arguments for targets is that it keeps you on track and gives you that numerical confirmation. However, in reality, I have found that as growth is not linear comparing progress against targets can feel arbitrary.

Nonetheless, I am keeping targets for myself. My spreadsheet has both net worth and FIRE fund targets for each month and year. I check my performance against these but I don’t allow myself to get too despondent or overjoyed based on them. They are more benchmarks or guiding lines really – where I realistically expect to be. Moreover, if my performance is away from the guiding lines it gives me the opportunity to check why that is – and usually, it’s all due to the pound’s instability (thanks Brexit) or market performance.

4 – Forecasting is hard

Which leads me to a concept that my science-minded brain struggles with. Financial forecasting is not a science, it’s more an art. You have to accept you cannot predict the future accurately. But you can predict bounds over the very long term with some degree of accuracy. And to be honest, this concept is one that I struggle with. How do you forecast something unforecastable?

The nuances and complexity are hard to grasp and get your head around. Nonetheless, over time I have become more and more confident in forecasting the future bounds – knowing what my future net worth and FIRE fund will look like with an average market return. As I spend more time contemplating and thinking through these concepts – I can see the different levers and how they impact the end result. And how external factors can have even bigger impacts.

My spreadsheet shows my previous simplistic forecasting methods and their evolution to the present. Moreover, the evolution in my thinking is evident.

5 – Flexibility is key

Ms ZiYou Flexibility

Following on from targets and forecasting is the general concept of flexibility and adaptability. My first iteration of modelling with the spreadsheet was static. And wrong. But I’m a firm believer that we all need to make mistakes to learn. Once I managed to get the spreadsheet to model compound interest rates correctly I realised it was still static. I needed to add some flexibility and what-if planning into to the analysis.

And that is the biggest item that gives me comfort in my numbers. As my spreadsheet has allowed me to run many many scenarios over the years I’ve been able to see the impacts of changes. And that has allowed me to see the impact of various spending levels after FIRE and how a part-time income could easily overcome any money shortages caused by a down market.

6 – You learn as you go along

I’m an experience based learner. While I can gain some knowledge from classroom-based or theory-based education, I learn best by doing. And by creating my own spreadsheet I have been getting intimately familiar with the maths behind financial independence. The nuances become more apparent – such as the complexity of tax. My pensions are tax-deferred, ISAs are after tax, and any future income from my taxable account or state pension is taxable.

Moreover, by creating my spreadsheet and catering for these nuances – I have learned a lot about my personal situation. I’ve been able to concentrate on issues that impact me, and just take a wider general brief on issues that don’t impact me. And it’s fascinating looking at how I have evolved and added these additional details into the spreadsheet to reflect my updated knowledge.

7 – Tradeoffs become apparent

Ms ZiYou Tradeoffs

I’ve always struggled with how to fund early retirement and not run out of money before my pension is available at 58. Hence I need to ensure I have enough money available that is not in a pension. However, saving money in a pension is much more tax efficient.

Reviewing the spreadsheet shows when I started to understand these concepts. Next, you can see several iterations of models to understand them which were then refined into today’s super duper bells and whistles model of this optimisation problem.

8 – Monthly Progress is not linear – but overall progress trends

One of the columns I have on my spreadsheet is looking at the monthly increase (or decrease) of my FIRE fund each month compared to the previous month. This ranges dramatically from -£11k to +£37k. And as my FIRE fund increases, you can see the swings getting larger each month. Clearly, there are some trends, but monthly progress is far from linear.

MsZiYou FIRE Fund Monthly Change

But then if you look at the bigger picture, the actual numerical value of the FIRE fund over time, the picture becomes clearer. I’m sure you can agree there are definite trends seen here, even if the monthly increases are not at all consistent.


I’ve learned it’s good to track monthly progress, but measure trends over longer time periods. Sometimes you need the bigger picture to truly understand and make sense of everything.

9 – Functionality over Appearance

I’m not ashamed to say my spreadsheet is ugly. I’d never ever dare use such an ugly spreadsheet at work. Nonetheless, as my net worth spreadsheet is just for me I let it remain ugly. The colour scheme leaves a lot to be desired, and the layout is not optimised.

However, I love my spreadsheets functionality – it is adaptable and allows me to model numerous scenarios. And that matters much more to me than an aesthetically pleasing one – I am saving my energy for the things that really matter to me.

10 – Personalisation makes it work for me

As we often say, personal finance is personal. And nowhere is this more necessary than in a net worth spreadsheet. We are all unique with many commonalities, hence I believe past the basics you can be creative with your spreadsheet.

In my mind, you should track the following at a minimum.

  • Assets = items you own of value such as cash, shares, bonds, houses
  • Liabilities = money you owe such as mortgages, loans, credit cards, tax bills
  • Net worth = Assets – Liabilities
  • Spending  = what you spend in a year

Anything else is just gravy and should be adjusted to your personal preferences. You need to make sure your priorities get more screentime and graphing action. And leave other items on the sidelines until they become your priorities.

In my spreadsheets, you can see spending is not an issue for me, hence it is not analysed in much detail at all. However, pride of place currently is my FIRE fund, which is analysed in many different ways. You can also see a full tab dedicated to modelling the pre-pension period, to make see how my funds react to certain scenarios.

Moreover, the best tab by a mile is my list: things I want to do once FIRE. It’s an ever increasing list of lots of really fun (to me) activities across travel, learning and exercise. Most people would consider it strange to keep it with the numbers, but to me, it’s the ideal home.

Spreadsheets as anthropological insights

Despite their reputation as dry factual documents, spreadsheets are much more than that. As an anthropological document, they can be revisited to track ideas and preferences. Trends and insights can be gleaned from them, along with lots of personal preferences.

Rather than discard previous versions when a newer better model comes along, we should preserve them for later review. After the passage of time insights and learnings become much more obvious. I’m a firm believer that deeply understanding the past you is very relevant to becoming the future you.

Over to you

  • What are your thoughts?
  • Do you have similar financial tracking spreadsheet?
  • How has yours evolved over time?

Thank you for reading – please leave a comment below and join in the conversation. You can also connect on Twitter or contact me privately.


22 comments on “10 Insights from a net worth spreadsheet

  1. Do you also model the withdrawal phase at all? I have to admit that I didn’t before I FIREd, but the latest post on EarlyRetirementNow (SWR part 27) really got me thinking….

    1. Hi Jo – good question. I do model the withdrawal phase simply – and bung it through firecalc occasionally when I am bored. I really can’t face setting up Monte-Carlo simulations, but when I am bored one day…never say never!

  2. Great findings Ms. ZiYou,

    “#1 Documenting the good times” made me think.

    I think this is very typical human behavior AND the reason why most people never start building a nest egg. When your numbers are low, it’s very hard to see the potential. They don’t realize they need a small snow ball to get a big snow ball rolling. So they sit around and wait, hoping to win the lottery or maybe inherit some money. Only if this happens, the will consider investing it.

    Regarding the spread sheet.
    I have a similar spread sheet but I’m not tracking my net worth. To be honest, I have only made a very rough calculation of my total net worth once. I think your focus on your FIRE fund can be compared to my focus on Cash Flow. Total net worth doesn’t mean much to me, I can’t live from that number on a month to month basis when I FIRE. Most will be tied up in bricks and other similar assets that cannot be accessed immediately.

    A spread sheet is great to keep track of your progress. Posting the numbers online is a wonderful way to keep you committed. It’s like having a better version of a real life liability partner.

    1. Hi Jorgen – I think you are right there on #1. It’s very hard to see the potential if you don’t have much.

      And cool you are tracking cash flow instead – a completely different but equally valid approach – the parallels are clear. I don’t measure cash flow as well.

      And yes – posting them online is like have hundreds of accountability partners!

  3. #7 – Tradeoffs become apparent – I totally agree with this.
    One of my main worries is that whilst I can save a lot of money towards our SIPPS & LISAs, we are probably going to be ok when we are able to access them. With even modest growth, we’ll have a huge pension put. Square that with at the moment “taking home” less salary than we need to cover our monthly expenses means that our pre-retirement assets are not growing as fast and those are what we would need to FIRE.
    I think I cover this is a bit on my blog (

    The whole article struck a chord with me, many similarities and insights. I have been tracking my net worth for 17 years now and long ago I used to be confused that other people didn’t do the same – now I just take it for granted that this is something I do and others aren’t interested.
    Glad to see someone else is though. 😉

    1. Hi GFF – yes that is one of the areas I’m keen to balance and model – my pre pension pot money.

      Also, another reason why I’m anti-LISA and keeping my money in vanilla LISAs.

      I am very jealous of your 17 years of tracking…so many insights in one spreadsheet.

  4. I thoroughly enjoyed this post Ms ZiYou. As a finance-type I have many spreadsheets. Your point 5 is the most challenging thing for making good spreadsheets. It’s very hard to create flexibility for unexpected things (I imagine that programming is much the same). Point 9 is the best way to combat that. Good layouts and flow is very important for good spreadsheet design.

    I think a lot of the reason for not tracking the bad is because it becomes quite a chore to do if the spreadsheet isn’t working (it’s happened to me many times).

    As to forecasting, it’s very difficult. I understand that many people consider forecasting to be important. But quite frankly, I’m a sceptic. My job was reading and making forecasts every day. I can’t remember ever seeing a single ‘correct’ forecast. I’m too lazy to bother with it. I know that’s terrible advice, but I can get away with it.

    p.s. I used to give spreadsheet training in my old jobs – yes, I was one of those “spreadsheet guys”…

    1. Hi YFG – I am now getting the impression you have a suite of super duper automated spreadsheets that can be used to solve any numerical challenge.

      I agree forecasting is not really to know the future, it’s to give you some idea and generally results in a lot of explaining why the forecast did not work!

  5. I couldn’t agree more with you. There is so much to learn from net worth graph over time. I review mine quite often. I’m totally a finance geek too. All this information can help get much better at your finances or at your investing. It’s very important.

  6. I only keep track of my net worth (and mention it occasionally) only because other bloggers do. Like you with your FIRE fund, what I’m ‘worth’ isn’t half as important as my Future Fund which will be funding my early retirement and beyond.

    Forecasting is hard – the bad thing is that my Future fund has actually exceeded my original expectations so far but this could all come crashing down depending on the markets and my ability to maintain my savings rate.

    I’m ok with spreadsheets so mine look a bit like a ‘work dashboard’ only not so Risk Director-friendly haha! The sections I copy and paste on my blog are the easier-on-the-eye bits!

    My original FI plan didn’t even need a spreadsheet, it was all so simple! The plan’s changed a couple more times since and yes, I keep the old spreadsheets, just in case I’ve missed something as I’ve moved along!

    1. Yeah – Future Funds are the most important number for us to track – net worth is just another number.

      Not sure if I should say commiserations on your forecasting being so bad or congratulations on exceeding expectations!

      I do love the simplicity of the old fag packet plans …before we started committing them and analysing them to death.

  7. I also love my net worth spreadsheet. A detailed spreadsheet shows that you’re serious about finance. I like sites like Mint and Personal Finance, but they can’t beat a spreadsheet. Putting info down on a spreadsheet makes you think.
    For me, net worth is more important than the FIRE fund. We can already support our lifestyle with passive income + blog income. So I don’t worry about it much.
    We should be in great shape if we can leave our retirement accounts alone, 401k and IRA.

    1. I agree – a spreadsheet shows you are serious. And we’re not as lucky as people in the US – we’ve got nothing comparable to personal capital or Mint sadly.

  8. I love my excel spreadsheets! I added tons of tabs over the years, some I don’t use anymore others are all new. I do wish I started much earlier so I could make better comparison but at least I am doing it now.

  9. Been using spreadsheets for over 25 years, I’ve gone over broad with the multitude of spreadsheets/tabs to track snapshots of my past financial history and some kind of simplistic projection, always evolving.

    My main sheet is a yearly networth table, I don’t have goals but have a couple benchmarks I look at each year end.

    First is over last 12 years my networth has averaged an increase of 10%, so I benchmark if this trend continues.

    Second is networth increase compared to average UK household income, which I traffic light what I’m at – green above the average, amber zero to the average, red below zero (networth gone down). With this one it’ll get to a point when it’s not relevent to me to use as a benchmark, this year it’s around the amber/red mark so will stay a little longer – I blame brexit 😉

    Finally I take the 4% SWR of my current networth and compare to my salary, currently equates to a 1/3rd and I’m projecting when it could get to 2/3rds, the same as a traditional final salary payment.

    1. That’s very impressive you have 25 years of spreadsheet history to review. Awesome.

      Benchmarks vs targets is a good way of measuring performances – 10% increase each year is epic.

      Thanks for sharing all those approaches – it’s cool to hear different perspectives and see what is important to them.

What do you think?