Save time tracking and comparing your buy-to-let prospects

Are you looking for a buy-to-let investment property?

Do you have lots of Rightmove and Zoopla links you’re trying to keep track of and compare? Perhaps stored in a spreadsheet? Maybe in several spreadsheets, with financial forecasts and calculations?

We can make life simpler and save you hours with our buy-to-let prospecting tool.

Keep reading to see how it will improve your property search.

Get started, quickly

Setting up your financial criteria and adding your first prospect property is only three quick steps.

Add your buy-to-let prospects

Adding each of your buy-to-let prospects is quick and easy. Just enter a label and three key figures (price, repairs and rent) to get a new property on your list.

Other details are optional but the more you provide the more the system can help you. You can always edit properties later to add more details.


Do you often spot great buy-to-let prospects while browsing your favourite property listing site?

Just drag our Bookmarklet (near the top right of your prospect listing page) to your browser bookmarks bar. Then click it whenever you’re viewing a property you think could be a great buy. You’ll be able to add the new prospect faster than ever.

Instant calculations

As soon as you’ve added your first buy-to-let prospect, you’ll be able to see three purchase scenarios for it – the asking price, your expected offer and your offer with minimum cash investment.

Buy-to-let prospects listing

You can see the stamp duty, cash you’ll need to invest, mortgage and yield for each scenario on each of your buy-to-let prospects.

Immediately see what you can afford

Your buy-to-let property listing also highlights any figures that you can’t afford (based on your investment/mortgage criteria) in red and any that are on the edge, in yellow.

Minimum cash

Trying to minimise your up-front cash investment for your next buy-to-let investment?

Then keep an eye on the “Min cash” scenario for each property. This line will work out the maximum mortgage your criteria will allow and then tell you the minimum amount of cash you’ll have to put in. It will also highlight it in red if that’s more than the amount of cash available.

Quickly compare and sort your prospect list

Once you’ve got a few buy-to-let prospects added, you can compare the key metrics quickly and easily on the listing page.

For even easier comparison you can change the order they’re sorted in. Lots of options are available including profit, required cash, price and rent.

Detailed financial forecasts

The listing page is just a summary though. The system has lots more details and calculations to show you for each buy-to-let property prospect you’re considering.

Click on “Asking”, “Offer” or “Min cash” for any of your properties to be taken to the detailed report and financial forecast for that property and scenario. You’ll see figures for the expected rental profit per month and year. Also how the mortgage tax relief changes will affect it in the next few years.

Keep notes

Every property in your list has a space for notes. You can edit this any time, adding to it as you research, visit and learn about the property. You can note the parking is bad, or list the repairs it needs.

Change notifications

If you’re spreadsheets do this, you’ve definitely spent too long working on them!

Enter a Rightmove property URL for your buy-to-let prospect and PaTMa will keep an eye on it for you. We’ll send you an email if that property changes price, is marked as sold or gets withdrawn.

Start saving time now

Save time building your buy-to-let portfolio.

It takes less than 5 minutes to create a free account and create your first buy-to-let prospect.

Rental cover for buy-to-let mortgages, how to calculate

The amount you can borrow on a buy-to-let mortgage will currently be restricted by two main criteria (possibly more for “portfolio landlords”). These are Loan To Value (LTV) and Rental Cover (or just Rent Cover).

Don’t want to know the calculations? You can quickly check if your next purchase satisfies the rental cover with our buy-to-let calculator.

What is Rental Cover?

Rental Cover is a relatively new restriction that’s now being placed on all buy-to-let mortgages. This value is the percentage of the mortgage (at a stress rate) that the rent must be. A fairly standard value for it is 150% but it varies between lenders and also on your own situation. Scroll down for some examples.

There are three useful sums related to rental cover, depending on what you know and which you’re trying to calculate. The sections below each detail one of the calculations, complete with an excel formula for it.

Calculate minimum required rent from mortgage and rental cover

For this you need to know how much you’ll be borrowing in your mortgage and what their rental cover requirements are (including the stress rate they use).

Here’s the calculation (followed by an example):

(([mortgage] * [stress rate]) / 12) * [rental cover] = [required rent]

Here’s an example: £150,000 mortgage, 5.5% stress rate, 150% rental cover.

This makes the calculation:

((150000 * 0.055) / 12) * 1.5 = 1031.25

We can split it up and explain the calculation in two parts:

First, calculating what the mortgage payments would be at the “stress” interest rate:

150000 * 0.055 / 12 = 687.50

Then multiply that up to provide the required rent for 150% cover:

687.5 * 1.5 = £1,031.25

So to get the mortgage you’ll need to prove the property can fetch a rent of £1,031.25 per month.

You can copy (and adapt) this Excel formula for use in your own spreadsheets:


Where: A1 is your mortgage borrowing, B1 is the stress rate (as a fraction / with percentage formatting) and C1 is the rental cover required (also as a fraction / percentage).

A fully working Excel example is also available for download.

Calculate maximum mortgage from rent and rental cover

Here you know the rent you’re expecting and the mortgage rental cover requirements, so want to calculate the maximum you’ll be able to borrow.

You can use this calculation:

(([monthly rent] * 12) / [stress rate]) / [rental cover] = [max mortgage]

Let’s look at an example: £900 monthly rent, 5.5% stress rate and 150% rental cover.

Making the calculation as follows:

((900 * 12) / 0.055) / 1.5 = 130909.09

Meaning the maximum mortgage you’ll be able to borrow in this situation is £130,909.09 (assuming you also satisfy LTV and other requirements).

Here’s an Excel formula version for use in your own spreadsheets:


Where: A1 is your monthly rent, B1 is the stress rate (as a fraction / with percentage formatting) and C1 is the rental cover required (also as a fraction / percentage).

A fully working Excel example is also available for download.

Calculate rental cover from mortgage and rent

In this final scenario you know how much you need to borrow as a mortgage and you know what rent you’ll be able to get, but what rental cover does that equate to (and hence will it satisfy your mortgage company). For this you will already need to know the stress rate that’s being applied though.

This is the calculation:

[monthly rent] / (([mortgage] * [stress rate]) / 12) = [rental cover]

This spits out the rental cover as a fraction so you’ll need to multiply it by 100 to get back to a percentage.

Here’s another example: £900 monthly rent, £180,000 mortgage required, 5.5% stress rate.

Which works out like this:

900 / ((180000 * 0.055) / 12) = 1.09

Hence our rent in this scenario only provides 109% rental cover – looks like we’ll need to find a different property.

The final Excel formula for you to use and adapt in your own spreadsheets:


Where: A1 is your monthly rent, B1 is the mortgage you need and C1 is the stress rate (as a fraction / with percentage formatting).

A fully working Excel example is also available for download.

Want an easier option?

Do you just want to know if you can afford the house you’re looking at?

Or just want to know the maximum mortgage you could get on it?

Then take a look at our buy-to-let prospecting tool to quickly track all the properties you’re considering. Complete with all the calculations and comparisons done for you.

Create your buy-to-let investment scenario

You want to purchase a buy-to-let property. You’ve got a deposit saved up and you’ve had a chat with a friendly mortgage broker to see what’s available. So now you just need to choose a property to buy.

That’s exactly where our buy-to-let prospecting tool will make life a lot easier for you. You simply enter your financial criteria and then carry on with your normal property search. Add each property you like to your personal list and the system will calculate all the figures you need These include profit and yield forecasts.

In this blog post, we’ll show you how to get started in three easy steps.

1. Register on PaTMa

You can register for free and even store your first three potential buy-to-let properties to get a feel for the system.

Start on our pricing page and click “Create Account” for free (or “Buy Now” for the Advanced or Agent Plus packages if you’re already convinced).

After registering, make sure that your click on “Prospects” in the top navigation. The screen should be headed “Your Prospects” just like this:

From there, click the “first prospect” link to get started.

2. Add your first prospect property

Get started by adding your first prospect – one of the properties you’re considering buying as your letting investment.

Here’s the form as it looks today (we’ve got some exciting enhancements coming soon, create your account now to receive emails as we update). I’ve included some example values.

Fill in the “Source URL” box to have a convenient link back to the full property details. If that URL is on Rightmove you can also press “Fetch values” to get a few details auto-filled for you.

Then fill in the rest of the information you want to store about the property you’re considering. If you need them, there are details on the financial figures used here.

Once you’ve filled in everything you want to (at least including the ones marked with an asterisk), click “Create Prospect” and you’ll be taken back to the prospect listing page.

3. Set your own criteria

At this point you’ll probably notice that the calculated numbers are mostly nonsense! This is because the system automatically creates your initial “criteria” – the financial situation and restrictions you’re working in. These default values almost certainly wont be right for you.

So let’s change them. Click the “edit” link near the top right of the listing screen – on the row with the criteria numbers.

You’ll see a screen with all the buy-to-let financial criteria details you can change, it should look like this.

Here you need to fill in how much cash you have available to spend.  This should be for everything, not just what you expect to put into a deposit. Then enter your expected legal fees and the mortgage figures you expect to get.

Some of these numbers, especially the mortgage restriction ones, are less obvious so please do read out previous buy-to-let profit calculator guide for more details.

With your criteria updated, click “Save” to be returned to your prospect list, complete with your calculations.

That’s it! You’re all set to add more properties to see which you can afford at what price. Sort them by yield or cash required or over ten other values.

Click on any of the price scenarios to see the full buy-to-let profit calculations (see our explanation of all the buy-to-let profit figures).

Edit each property at any time as you discover more information or want to record some notes after your viewing.

Create an account to compare your first three properties for free now.


Understanding buy-to-let profit calculator results

So you’ve read our last blog post about all the figures you need to feed into our buy-to-let profit calculator, filled it in and got your results. But what do they mean? Keep reading to find out.

Let’s go through the results one section at a time.

Your Investment

Buy-to-let profit calculator investment results

You should recognise a few of these as figures that you provided to the calculator. These are repeated back for easy reference and so you can see how they’re connected. “Purchase Price”, “Repair Costs” and “Fees” are the ones that should be familiar so I’ll just go over the others.

Total Investment

This is the amount of actual cash you’ll need to put into the purchase. The elements that make it up are shown underneath, each indented a little.

Look here first to see if you can actually afford the deal you’re considering. If this number is bigger than your bank balance, things are going to be tricky.

If you included a “Cash Available” figure in the calculator inputs, this will match.

Stamp Duty

The calculated SDLT that’s due on the purchase price, including the 3% second home addition. You can see all the detail on how stamp duty is calculated and grab an Excel version from our past post.


The cash you’ll actually be putting into the house itself. This is either calculated as everything spare from your “Cash Available”, after other deductions; or it’s the minimum amount your mortgage restrictions will allow.


The amount you’re going to end up borrowing from your mortgage provider. Also shown is what that equates to as a LTV percentage.

This row will be yellow if LTV is the restricting factor on how much you can borrow. Or red if you’ve set a “Cash Available” which isn’t high enough to satisfy the LTV required.

Rent Cover

“Rent cover” or “rental cover” are a relatively new restriction that’s being placed on buy-to-let mortgages.

The value shown is the percentage of the mortgage (at the stress interest rate) that the rental income is.

This row will be yellow if rent cover is the restricting factor on how much you can borrow. Or red if you’ve set a “Cash Available” which isn’t high enough to satisfy the rental cover required.

Monthly Forecast

Buy-to-let profit calculator monthly forecast

This is where it really starts to get interesting. The first figure should be familiar as it’s just the forecast monthly rent that you entered. Let’s look at each of the others.

Mortgage Interest

Nothing controversial here, just the monthly payment on your expected mortgage. Based on the interest rate you filled in and the calculated borrowing amount (see above).

Misc Expenses

This one could be a little more controversial. Trying to forecast expenses with buy-to-let investments is never straight forward. A lot of factors will make this vary, one of the main examples will be whether you use a managing agent, introduction agent or do it yourself. But it also depends on things like your level of insurance and how many voids you get. That’s before we start thinking about single lets vs HMOs vs holiday lets.

Currently our buy-to-let profit calculator rolls this all up into an (evidence based) educated guess based on single lets.

This expenses figure shown will be 15% of the expected rental income.


Back to being simple – this is just your monthly rent minus mortgage, minus expenses.

Annual (and Yield) Forecast

Buy-to-let profit calculator annual forecast

This section mostly saves you multiplying the previous section by twelve. The “Rent”, “Mortgage Interest”, “Misc Expenses” and “Profit” all have the same meaning as in the monthly forecast but multiplied by twelve to cover a whole year.


Yield is normally calculated as an annual figure and hence it makes an appearance in this section.

This yield is calculated using the “Profit” returned from the “Total Investment” you’re putting in.

Looking to the Future!

Buy-to-let profit calculator 5-year forecast

A lot can change in five years and you should only treat this section as a quick guide. We don’t take into account any rent rises or changes to your mortgage interest rate. We don’t consider any value improvement from building or repair works. And we do assume a flat capital value increase of 3% per year. So in summary – these numbers will be wrong!

We still find these numbers can be useful though and hope that you do too.

Mortgage Interest Tax Changes Forecast

Buy-to-let profit calculator mortgage interest tax change forecast

Last, but very definitely not least is an exceptionally important set of numbers for all higher rate tax payers. Hopefully you already know about the changes to mortgage interest tax relief that started to take effect this year.

All the buy-to-let profit calculations so far have been pre-tax. But there’s a massive change happening over the next few years in how landlords will be calculating their tax so you should always look at this part of the results. A property that turns a nice profit today could potentially be making a loss (after tax) in a few years time.

To read these results, pick the column that matches the tax band that you’re in and read down those numbers. These are the amounts you can actually expect to put in your pocket.

You can also hover your mouse over any of the post-tax profit figures to see a little extra detail.

Buy-to-let profit calculator post tax yield

Try it now

You can quickly and easily get all these figures for your next buy-to-let investment right now with our free buy-to-let profit calculator.

If you’re planning to remortgage your existing investment properties or perhaps just wondering about what the tax changes will mean for you try our free buy-to-let remortgage calculator.

Glossary of fields in our free buy-to-let profit calculator

The PaTMa buy-to-let profit calculator will instantly turn 10 numbers into a straight forward guide to how much your next buy-to-let could make. And six of those numbers have sensible defaults and another one is optional. So really you only need 3 numbers to get started!

This post is going to walk through each of the numbers you can feed into the calculator and explain exactly what they mean.

When you first view the buy-to-let profit calculator the fields you can complete are shown down the left hand side. For easier viewing, the image here is split into two columns. Other than that it shows how they first appear, complete with default values.

Profit calculator questions

Expected price

This is the price you expect (or want) to be paying for the property. Enter the full amount just as number (no pound signs).

Initial repair cost

How much do you expect to pay to get the property ready to rent? There are lots of things this might include from just a good clean and some paint to moving walls, a new kitchen, bathrooms and carpet. Remember to include costs that may occur while work is being done, eg council tax, utilities and any finance costs.

Forecast monthly rent

How much will you be able to rent the property for? This should be the monthly amount you’ll be receiving.

Soon you’ll be able to tune the expenses applied to this to include utility bills and other costs that suitable for HMOs and other letting situations. For now though, you can still use the profit calculator by entering the amount you expect to have left after utilities and tax.

Cash available

How much cash do you want to invest? This will need to cover the deposit, repairs and stamp duty.

You can leave this blank and the calculator will tell you the minimum amount of cash you need to buy the property. Alternatively, enter a value and the calculator will tell you if you can’t afford it or reduce your mortgage and show how that affects your profit.

Legal fees

Enter the amount you expect to spend on your solicitor, search and transaction fees.

We currently provide a default of £1,000 which we hope is an OK guess for an average transaction.

Mortgage rate (%)

What interest rate will you be paying for your mortgage?

Our currently default value is 3.5% which might be about right for a limited company mortgage or a higher risk personal mortgage (at the moment). Lower risk (lower LTV) personal mortgages might have fixed rates of around 2% at the moment.

Mortgage fees

How much will your mortgage cost to get setup? This might include a survey fee, broker fee and a general setup fee.

We currently default this to £1,999 which is probably a bit on the high side, but better that than estimating too low. Check with your mortgage supplier for the correct value.

Max LTV (%)

This and the next two are all about the restrictions the lender is placing on the mortgage you expect to get.

The “maximum loan to value” is a standard mortgage restriction and for buy-to-let mortgages today it might be as low as 65% or perhaps as high as 85%. You’ll need to check with your mortgage broker to know what’s available to you.

Required rent cover (%)

“Rent cover” or “rental cover” are a relatively new restriction that’s being placed on buy-to-let mortgages. This value is the percentage of the mortgage (at stress rate, see below) that the rent must be.

A fairly standard value for this is 150% but it varies between lenders and based on your own situation.

Stress rate (%)

The interest rate used to calculate mortgage payments for the rent cover calculation (see above).

Again these vary between lenders and with your personal circumstances, we default to 5.5% as a fairly safe starting point. Adjust this based on talking to your mortgage broker.


With all the details above filled in for your scenario, hit the Calculate button to see your results, they’ll look something like this:

Profit calculator result screenshot

Try for free

Our buy-to-let profit calculator is completely free so why not give it a go now, click here.