Our Tools

These are our current set of tools. The links here will send you to the part of this page that describes how to use them and also includes the download link. All tools are as seen, tried and tested and The Money Principle does not warrant their usefulness or accuracy. They are for educational and planning purposes only.

Net Worth | Budgeting | Retirement – income required to 100 | Nutmeg ROI

TMP Net worth calculator

This calculator allows you to follow your net wealth regularly. Once compiled it is very easy to change. One difference between other calculators and this one is that the cash value of life insurance has been included as an asset.

Whether you choose to include it or not is up to you; we think that there are very good reasons to account for it when calculating your net worth.

TMP Monthly Budget Planner

This budgeting tool allows you to follow your monthly income and spending, calculates your monthly cash flow (the difference between income and spends) and provides the detail necessary to manage your money efficiently and effectively.

Three different categories of spending have been assumed:

  • Constant expenditure: this includes all spending lines that don’t change very often.
  • Changeable expenditure: includes all spending that can be negotiated at certain times like insurance, telephony etc.
  • Variable expenditure: this includes food, drinks, clothes, entertainment etc. and is the part of your budget that is easiest to reduce fast. It is also the part of your budget that can easily expand and should be carefully watched.

Please note:

  • The part of the budget tool that needs updating every month is the ‘variable expenditure’;
  • This looks very detained but: a) you can do it in as much or as little detail you find useful; and b) even the detailed version take no more than an hour and a half per month if you collect all receipts for food in a folder and process then in one go.
  • The last spread sheet is an aggregate of your annual spending by category of expenditure.

Have fun playing with TMP budgeting tool and enjoy watching your cash flow increase.

TMP Retirement Calculator

There are many retirement calculators around but this one is a calculator with a difference. It allows you to change the assumptions regarding:

  • Retirement age;
  • Spending per year;
  • Base income (in our case this is occupational pensions we know we’ll have)
  • Level of money pot (savings/investments);
  • Inflation;
  • Yields;
  • And care requirements (age, costs etc.)

Please note:

  • To be able to set the numbers so that they ‘make sense’ you need to have a good idea of the life style you intend to lead when retired.
  • Our assumptions seem generous on the ‘spending per year’ but we plan to travel and live in other countries; donate generously to charities and trying to do a bit of good. What use is money otherwise?

TMP Nutmeg Investment Calculator

This enables you to estimate your return on investment in Nutmeg (or anything really as long as you can extract a daily fund value), as described in our report.


  • Start date (all other dates are calculated automatically)
  • Your periodic investments (just on the day you invest)
  • The Offset allowance – an amount subtracted from the investment and outturn values to pending actual investment
  • Your daily portfolio valuations – the actual portfolio values reported by Nutmeg on a day-by-day basis

Pending Nutmeg making these available as a download, you can get these from apps.nutmeg.com/portfolio/dig_deeper when logged in and view the page source.  It is in a block towards the bottom of the page that starts something like:

//<![CDATA[ $amp;(function() { PortfolioPerformanceChart.render(‘stockchart’, [[1365033600000,1000], …

and ends something like:

… [1376179200000,12188]],false); }); //]]>

The long number is the time in milliseconds which you can decode but the number you want is the numeric value by it – this is the portfolio value on that day.