Mortgages Exposed On-Line Spreadsheets - Summary

Spreadsheet Summary (Updated 29th May 2009)

Note:  Only Excel spreadsheets are now periodically updated.

You can download each spreadsheet individually and run them immediately by selecting one from the alphabetical list below. The sizes range from 19k to 252k so the download time should be minimal.  Alternatively, you can download the whole set as a self-extracting file,  Excel (538 KB) or Lotus (406 KB).  If you have a choice, the Excel files include better formatting, conditional formatting and data validation in some cases.

Spreadsheets to calculate residential mortgage figures:-

Buy or Rent (Excel (49k) or Lotus)
Choose first whether to buy or rent a house by entering your own ideas of the future.  An immediate graph indicates when the optimum breakeven point occurs in terms of how long you stay in the property.  

Mortgage Scheme Select Wizard (Excel (55k) or Lotus) See also on-line tools
Answer three simple questions to see which type of mortgage scheme suits you, and an explanation of each scheme.

Mortgage (Excel (31k) or Lotus)
A simple spreadsheet to illustrate the use of formulae in basic mortgage calculations. Amended 24 Oct 07.

Mortgage Affordability (Excel (19k) or Lotus 123)
A simple spreadsheet to calculate the mortgage advance to match what you can afford each month and an indication of the income you need.

Loan Comparator (Excel (112k ) or Lotus)
Use this to accurately compare any two mortgage or loan products using the IRR (Internal Rate of Return) method.  Calculates APR as well and supports up to two interest rate changes, illustrating the monthly payments.  Probably the most useful spreadsheet of all for serious mortgage seekers. Also calculates ‘cash now’ equivalent to compare the best buy.

Mortgage Illustration and Comparator (Excel (174k ) or Lotus) See also on-line tools
Ideal for calculating and illustrating the key variables of a mortgage, including a payment schedule over the life of the loan, and a comparison tool.

Remortgage Check (Excel (30k) or Lotus) See also on-line tools
Determine whether it is worthwhile switching to another mortgage scheme by calculating the potential savings as a lump sum “Present Value”.

Spreadsheets to calculate more complex mortgage figures:-

Current Account Mortgage (Excel (253k) or Lotus)
Understand how this very flexible mortgage operates.  Choose any monthly payment, credit or debit and graph the results.

Flexible Mortgage (Excel (65k) or Lotus)
Enter your own mortgage payment schedule and future interest rates:  see some examples of how to use a flexible mortgage.

Investment and Mortgage Calculator  Excel (38k) or Lotus
Illustrating the effect of using a savings scheme alongside an interest-only mortgage, and calculating the optimum savings rate from a given performance estimate.  Includes two examples.

Spreadsheets to illustrate house prices:-

Regional Property Values (Excel (139k) or Lotus) Excel updated quarterly
Using regional indices since 1973, see how house prices have changed region-by-region, and estimate your own property value.

Spreadsheets for property investments:-

Investment Property Returns (Excel (38k) or Lotus) See also on-line tools
A useful spreadsheet for those interested in buy-to-let or commercial property as an investment.  Estimate the return on capital for almost any scenario.  Determine when it pays to borrow and use gearing to enhance your return.

Commercial Investment Property Returns (Excel only 40k)
As Investment Property Returns (above) but biased towards commercial property rather than buy-to-let.

Commercial Property Investment IRR Calculations (Excel only 53k)
Enter details for any typical commercial property with quarterly rents and mortgage payments and calculate the IRR over any term assuming any quarterly change to rates or rents.

Property Portfolio (Excel (39k) or Lotus)
A dynamic example of how to build up a portfolio of 16 commercial properties over twenty years using mortgages and re-invested rental income and, given initial assumptions, immediately calculate the surprising outcome.

Spreadsheets for miscellaneous purposes:-

Monthly Mortgage Schedule (Excel Only (38k))
List and graph any monthly mortgage payment schedule against property equity with any interest rate or growth rate in each year.  Ideal for calculating payments when changing from interest-only to capital repayment after a period.

Mortgage Product Design (Excel (70k))
Useful for a mortgage broker/agent to design his own product to yield the lender's desired return, but choosing various discount schedules and cashbacks.  Macros must be enabled in Excel. 

Mortgage & Loan Product Design (Excel (66k) or Lotus)
Useful for a lender to help determine the margin required on any loan product.  Then using “Goal Seek” macros, it will calculate backwards to determine say the cashback or discount that can be offered to match the required margin. Macros must be enabled.

APR Calculator (Excel (77k) or Lotus) TCC Bug fixed 29 May 09
A general-purpose APR (Annual Percentage Rate) calculator, illustrating the use of “Goal Seek” (or Backsolver in Lotus).  It is designed for long term loans where there may be an interest rate change every year, and some regular or one-off monthly or annual fees or charges.  The Macro button automates the process. Macros must be enabled in Excel.

Project IRR (Excel (36k) or Lotus)
Take any project with monthly cashflows and calculate the IRR

Quarterly Mortgage Schedule (Excel Only (91k))
List and graph any quarterly mortgage payment schedule against property equity with any interest rate or growth rate in each year.  Useful in planning commercial mortgage payment schedules, particularly for calculating payments when changing from interest-only to capital repayment after a period.

Mortgage Exposed Part I (Excel (153k) or Lotus)
A summary of the figures used in the tables in Part I of “Mortgages Exposed” in simple, unprotected spreadsheets so that the beginner can get some idea how the sheets are constructed.

Spreadsheets for classical products:-

Flexible Payment Mortgage (Excel (59k)or Lotus)
The product of the eighties, which included a low-start option and flexible payments.  This sheet is more of historical interest rather than practical value.

Index Linked (Excel (34k) or Lotus)
The first residential mortgage linked to inflation.  As with the flexible payment mortgage, it is of historical and mathematical interest only.

Reverse Mortgages (Excel (28k) or Lotus)
Illustrating an unusual scheme to compete with home reversions for those over fifty who are house rich but cash poor.

Rule of 78 (Excel (26k) or Lotus)
Illustrating how to calculate the early settlement of a loan using this method.