MTDRecognised by HMRC for Making Tax DigitalRecognised by HMRC for Making Tax Digital

LetComplianceLandlord & property management software

Sign in Get started

Sign in Get started

Plans from £7.99 a month.

For agents, brokers and landlord blogs

Property calculators for your website

17 landlord and buy-to-let calculators you can put on your own site with one paste: rental yield, stamp duty, the mortgage stress test, Section 24, rent affordability and more. No account, no fee. Each one sizes itself to your page and carries a one-line credit to LetCompliance underneath.

Calculators: 17
Cost: None
Account: Not needed

How it works

On your page in about a minute

Pick a calculator
Preview any of them first: the preview is the tool page, the embed is the calculator on its own.
Copy the code
Three lines: the frame, a credit line, and a small script that sizes the frame to the calculator.
Add it to your page
WordPress: a Custom HTML block. Squarespace: a Code block. Wix: Embed HTML. Any page builder that accepts HTML works the same way.

The calculators

17 to choose from

Each is the same calculator that runs on its tool page here, without the page around it.

Rental yield

Gross yield is a vanity metric. See your real net return after mortgage, running costs and tax, the same numbers your portfolio dashboard runs on every property in LetCompliance.

Get the code

<iframe src="https://letcompliance.com/embed/rental-yield-calculator" title="Rental yield" width="100%" height="1600" loading="lazy" style="border:0;max-width:760px;display:block"></iframe>
<p style="margin:6px 0 0;font:13px/1.5 system-ui,sans-serif">Rental yield by <a href="https://letcompliance.com/tools/rental-yield-calculator">LetCompliance</a></p>
<script>addEventListener("message",function(e){if(e.origin!=="https://letcompliance.com"||!e.data||e.data.type!=="letcompliance-embed-height")return;document.querySelectorAll('iframe[src^="https://letcompliance.com/embed/"]').forEach(function(f){if(f.contentWindow===e.source)f.style.height=e.data.height+"px"})});</script>

Paste into any page that accepts HTML.

Stamp Duty BTL

SDLT on buy-to-let is complex. Residential rates + 5% additional-property surcharge + 2% non-resident surcharge. Get the exact bill before you offer.

Get the code

<iframe src="https://letcompliance.com/embed/stamp-duty-buy-to-let-calculator" title="Stamp Duty BTL" width="100%" height="1150" loading="lazy" style="border:0;max-width:760px;display:block"></iframe>
<p style="margin:6px 0 0;font:13px/1.5 system-ui,sans-serif">Stamp Duty BTL by <a href="https://letcompliance.com/tools/stamp-duty-buy-to-let-calculator">LetCompliance</a></p>
<script>addEventListener("message",function(e){if(e.origin!=="https://letcompliance.com"||!e.data||e.data.type!=="letcompliance-embed-height")return;document.querySelectorAll('iframe[src^="https://letcompliance.com/embed/"]').forEach(function(f){if(f.contentWindow===e.source)f.style.height=e.data.height+"px"})});</script>

Paste into any page that accepts HTML.

BTL stress test

Every UK BTL lender stress-tests your rent at 5.5%–7% with ICR of 125% (basic-rate) or 145% (higher-rate). See the maximum loan your rent supports.

Get the code

<iframe src="https://letcompliance.com/embed/btl-mortgage-stress-test-calculator" title="BTL stress test" width="100%" height="1300" loading="lazy" style="border:0;max-width:760px;display:block"></iframe>
<p style="margin:6px 0 0;font:13px/1.5 system-ui,sans-serif">BTL stress test by <a href="https://letcompliance.com/tools/btl-mortgage-stress-test-calculator">LetCompliance</a></p>
<script>addEventListener("message",function(e){if(e.origin!=="https://letcompliance.com"||!e.data||e.data.type!=="letcompliance-embed-height")return;document.querySelectorAll('iframe[src^="https://letcompliance.com/embed/"]').forEach(function(f){if(f.contentWindow===e.source)f.style.height=e.data.height+"px"})});</script>

Paste into any page that accepts HTML.

HMO mortgage

HMO lenders stress per-room rent at 5.5%–8% with ICR up to 170% for higher-rate landlords. See the maximum loan your room income actually supports, before you offer.

Get the code

<iframe src="https://letcompliance.com/embed/hmo-mortgage-calculator" title="HMO mortgage" width="100%" height="1500" loading="lazy" style="border:0;max-width:760px;display:block"></iframe>
<p style="margin:6px 0 0;font:13px/1.5 system-ui,sans-serif">HMO mortgage by <a href="https://letcompliance.com/tools/hmo-mortgage-calculator">LetCompliance</a></p>
<script>addEventListener("message",function(e){if(e.origin!=="https://letcompliance.com"||!e.data||e.data.type!=="letcompliance-embed-height")return;document.querySelectorAll('iframe[src^="https://letcompliance.com/embed/"]').forEach(function(f){if(f.contentWindow===e.source)f.style.height=e.data.height+"px"})});</script>

Paste into any page that accepts HTML.

Section 24 tax

Section 24 doesn’t just take away your deduction, it can shove your rental profit into the higher-rate band even when your cash position is basic-rate. See the real number for your portfolio.

Get the code

<iframe src="https://letcompliance.com/embed/section-24-mortgage-interest-calculator" title="Section 24 tax" width="100%" height="1400" loading="lazy" style="border:0;max-width:760px;display:block"></iframe>
<p style="margin:6px 0 0;font:13px/1.5 system-ui,sans-serif">Section 24 tax by <a href="https://letcompliance.com/tools/section-24-mortgage-interest-calculator">LetCompliance</a></p>
<script>addEventListener("message",function(e){if(e.origin!=="https://letcompliance.com"||!e.data||e.data.type!=="letcompliance-embed-height")return;document.querySelectorAll('iframe[src^="https://letcompliance.com/embed/"]').forEach(function(f){if(f.contentWindow===e.source)f.style.height=e.data.height+"px"})});</script>

Paste into any page that accepts HTML.

Rental income tax

Rental profit is taxed on top of your salary, so the marginal rate is what bites. Enter your numbers to see the real tax bill, the 20% mortgage-interest credit and what you actually keep.

Get the code

<iframe src="https://letcompliance.com/embed/rental-income-tax-calculator" title="Rental income tax" width="100%" height="1400" loading="lazy" style="border:0;max-width:760px;display:block"></iframe>
<p style="margin:6px 0 0;font:13px/1.5 system-ui,sans-serif">Rental income tax by <a href="https://letcompliance.com/tools/rental-income-tax-calculator">LetCompliance</a></p>
<script>addEventListener("message",function(e){if(e.origin!=="https://letcompliance.com"||!e.data||e.data.type!=="letcompliance-embed-height")return;document.querySelectorAll('iframe[src^="https://letcompliance.com/embed/"]').forEach(function(f){if(f.contentWindow===e.source)f.style.height=e.data.height+"px"})});</script>

Paste into any page that accepts HTML.

CGT on BTL

Selling a BTL? CGT rates changed in April 2024 and the allowance is now just £3,000. Plus you have 60 days from completion to report and pay. Run the numbers before you accept an offer.

Get the code

<iframe src="https://letcompliance.com/embed/cgt-buy-to-let-calculator" title="CGT on BTL" width="100%" height="1400" loading="lazy" style="border:0;max-width:760px;display:block"></iframe>
<p style="margin:6px 0 0;font:13px/1.5 system-ui,sans-serif">CGT on BTL by <a href="https://letcompliance.com/tools/cgt-buy-to-let-calculator">LetCompliance</a></p>
<script>addEventListener("message",function(e){if(e.origin!=="https://letcompliance.com"||!e.data||e.data.type!=="letcompliance-embed-height")return;document.querySelectorAll('iframe[src^="https://letcompliance.com/embed/"]').forEach(function(f){if(f.contentWindow===e.source)f.style.height=e.data.height+"px"})});</script>

Paste into any page that accepts HTML.

Pro rata rent

A tenancy almost never starts on the rent day, so the first payment is a part month. There is no legal formula and agreements use two different ones, which is why the same tenancy can produce two different first invoices. See both, and put the working on the demand.

Get the code

<iframe src="https://letcompliance.com/embed/pro-rata-rent-calculator" title="Pro rata rent" width="100%" height="1150" loading="lazy" style="border:0;max-width:760px;display:block"></iframe>
<p style="margin:6px 0 0;font:13px/1.5 system-ui,sans-serif">Pro rata rent by <a href="https://letcompliance.com/tools/pro-rata-rent-calculator">LetCompliance</a></p>
<script>addEventListener("message",function(e){if(e.origin!=="https://letcompliance.com"||!e.data||e.data.type!=="letcompliance-embed-height")return;document.querySelectorAll('iframe[src^="https://letcompliance.com/embed/"]').forEach(function(f){if(f.contentWindow===e.source)f.style.height=e.data.height+"px"})});</script>

Paste into any page that accepts HTML.

Rent affordability

Most UK referencing fails on one rule: gross income of 30× the monthly rent. Check any applicant in seconds, and see the guarantor income needed when they fall short.

Get the code

<iframe src="https://letcompliance.com/embed/rent-affordability-calculator" title="Rent affordability" width="100%" height="1200" loading="lazy" style="border:0;max-width:760px;display:block"></iframe>
<p style="margin:6px 0 0;font:13px/1.5 system-ui,sans-serif">Rent affordability by <a href="https://letcompliance.com/tools/rent-affordability-calculator">LetCompliance</a></p>
<script>addEventListener("message",function(e){if(e.origin!=="https://letcompliance.com"||!e.data||e.data.type!=="letcompliance-embed-height")return;document.querySelectorAll('iframe[src^="https://letcompliance.com/embed/"]').forEach(function(f){if(f.contentWindow===e.source)f.style.height=e.data.height+"px"})});</script>

Paste into any page that accepts HTML.

Letting agent fees

The headline 10–15% is never the real number. Add VAT, setup, inventory and renewal fees and the first-year cost is far higher. See your true all-in agent cost, then compare it to self-managing.

Get the code

<iframe src="https://letcompliance.com/embed/letting-agent-fee-calculator" title="Letting agent fees" width="100%" height="1600" loading="lazy" style="border:0;max-width:760px;display:block"></iframe>
<p style="margin:6px 0 0;font:13px/1.5 system-ui,sans-serif">Letting agent fees by <a href="https://letcompliance.com/tools/letting-agent-fee-calculator">LetCompliance</a></p>
<script>addEventListener("message",function(e){if(e.origin!=="https://letcompliance.com"||!e.data||e.data.type!=="letcompliance-embed-height")return;document.querySelectorAll('iframe[src^="https://letcompliance.com/embed/"]').forEach(function(f){if(f.contentWindow===e.source)f.style.height=e.data.height+"px"})});</script>

Paste into any page that accepts HTML.

Deposit cap

5 weeks’ rent under £50k annual, 6 weeks’ rent at or above £50k. Over the cap is a banned fee, returnable to the tenant, plus it blocks most Section 8 grounds. Get the exact lawful figure.

Get the code

<iframe src="https://letcompliance.com/embed/deposit-cap-calculator" title="Deposit cap" width="100%" height="1100" loading="lazy" style="border:0;max-width:760px;display:block"></iframe>
<p style="margin:6px 0 0;font:13px/1.5 system-ui,sans-serif">Deposit cap by <a href="https://letcompliance.com/tools/deposit-cap-calculator">LetCompliance</a></p>
<script>addEventListener("message",function(e){if(e.origin!=="https://letcompliance.com"||!e.data||e.data.type!=="letcompliance-embed-height")return;document.querySelectorAll('iframe[src^="https://letcompliance.com/embed/"]').forEach(function(f){if(f.contentWindow===e.source)f.style.height=e.data.height+"px"})});</script>

Paste into any page that accepts HTML.

Void cost

A 6-week void on a £1,500 BTL costs roughly £2,800 once council tax, bills and re-let fees are added. See the real number before you set the next asking rent.

Get the code

<iframe src="https://letcompliance.com/embed/void-cost-calculator" title="Void cost" width="100%" height="1500" loading="lazy" style="border:0;max-width:760px;display:block"></iframe>
<p style="margin:6px 0 0;font:13px/1.5 system-ui,sans-serif">Void cost by <a href="https://letcompliance.com/tools/void-cost-calculator">LetCompliance</a></p>
<script>addEventListener("message",function(e){if(e.origin!=="https://letcompliance.com"||!e.data||e.data.type!=="letcompliance-embed-height")return;document.querySelectorAll('iframe[src^="https://letcompliance.com/embed/"]').forEach(function(f){if(f.contentWindow===e.source)f.style.height=e.data.height+"px"})});</script>

Paste into any page that accepts HTML.

Making Tax Digital checker

Enter your rental and self-employment turnover and see the April it starts for you, then every quarterly update deadline and the Final Declaration date.

Get the code

<iframe src="https://letcompliance.com/embed/mtd-itsa-quarterly-deadline-calculator" title="Making Tax Digital checker" width="100%" height="1900" loading="lazy" style="border:0;max-width:760px;display:block"></iframe>
<p style="margin:6px 0 0;font:13px/1.5 system-ui,sans-serif">Making Tax Digital checker by <a href="https://letcompliance.com/tools/mtd-itsa-quarterly-deadline-calculator">LetCompliance</a></p>
<script>addEventListener("message",function(e){if(e.origin!=="https://letcompliance.com"||!e.data||e.data.type!=="letcompliance-embed-height")return;document.querySelectorAll('iframe[src^="https://letcompliance.com/embed/"]').forEach(function(f){if(f.contentWindow===e.source)f.style.height=e.data.height+"px"})});</script>

Paste into any page that accepts HTML.

Section 8 notice period

Ground 8 needs 4 weeks’ notice. Ground 1A needs 4 months and a 12-month tenancy. Ground 14 needs none. The Renters’ Rights Act made the rules longer, this tool keeps you valid.

Get the code

<iframe src="https://letcompliance.com/embed/rra-notice-period-calculator" title="Section 8 notice period" width="100%" height="1250" loading="lazy" style="border:0;max-width:760px;display:block"></iframe>
<p style="margin:6px 0 0;font:13px/1.5 system-ui,sans-serif">Section 8 notice period by <a href="https://letcompliance.com/tools/rra-notice-period-calculator">LetCompliance</a></p>
<script>addEventListener("message",function(e){if(e.origin!=="https://letcompliance.com"||!e.data||e.data.type!=="letcompliance-embed-height")return;document.querySelectorAll('iframe[src^="https://letcompliance.com/embed/"]').forEach(function(f){if(f.contentWindow===e.source)f.style.height=e.data.height+"px"})});</script>

Paste into any page that accepts HTML.

HMO all-in yield

Gross yield on purchase price flatters bad projects. See true all-in yield on total project cost and cash-on-cash after interest-only mortgage, management and bills.

Get the code

<iframe src="https://letcompliance.com/embed/hmo-all-in-yield-calculator" title="HMO all-in yield" width="100%" height="1950" loading="lazy" style="border:0;max-width:760px;display:block"></iframe>
<p style="margin:6px 0 0;font:13px/1.5 system-ui,sans-serif">HMO all-in yield by <a href="https://letcompliance.com/tools/hmo-all-in-yield-calculator">LetCompliance</a></p>
<script>addEventListener("message",function(e){if(e.origin!=="https://letcompliance.com"||!e.data||e.data.type!=="letcompliance-embed-height")return;document.querySelectorAll('iframe[src^="https://letcompliance.com/embed/"]').forEach(function(f){if(f.contentWindow===e.source)f.style.height=e.data.height+"px"})});</script>

Paste into any page that accepts HTML.

EPC retrofit cost

All privately rented homes need EPC C by 1 October 2030, with a £10,000 cost cap. See your retrofit bill before the deadline lands.

Get the code

<iframe src="https://letcompliance.com/embed/epc-retrofit-cost-calculator" title="EPC retrofit cost" width="100%" height="1750" loading="lazy" style="border:0;max-width:760px;display:block"></iframe>
<p style="margin:6px 0 0;font:13px/1.5 system-ui,sans-serif">EPC retrofit cost by <a href="https://letcompliance.com/tools/epc-retrofit-cost-calculator">LetCompliance</a></p>
<script>addEventListener("message",function(e){if(e.origin!=="https://letcompliance.com"||!e.data||e.data.type!=="letcompliance-embed-height")return;document.querySelectorAll('iframe[src^="https://letcompliance.com/embed/"]').forEach(function(f){if(f.contentWindow===e.source)f.style.height=e.data.height+"px"})});</script>

Paste into any page that accepts HTML.

Mileage claim

Driving to a viewing, an inspection or to meet a contractor is an allowable expense, and most landlords either forget it or use last year's rate. The first-band rate rose from 45p to 55p on 6 April 2026, so pick the year you are filing for.

Get the code

<iframe src="https://letcompliance.com/embed/landlord-mileage-calculator" title="Mileage claim" width="100%" height="950" loading="lazy" style="border:0;max-width:760px;display:block"></iframe>
<p style="margin:6px 0 0;font:13px/1.5 system-ui,sans-serif">Mileage claim by <a href="https://letcompliance.com/tools/landlord-mileage-calculator">LetCompliance</a></p>
<script>addEventListener("message",function(e){if(e.origin!=="https://letcompliance.com"||!e.data||e.data.type!=="letcompliance-embed-height")return;document.querySelectorAll('iframe[src^="https://letcompliance.com/embed/"]').forEach(function(f){if(f.contentWindow===e.source)f.style.height=e.data.height+"px"})});</script>

Paste into any page that accepts HTML.

FAQs

Before you paste

Does it cost anything?

No. There is no fee, no account and no limit on visits. The one condition is that the credit line under the calculator stays in place.

Do the figures stay current?

Yes. The calculator is served from LetCompliance rather than copied onto your site, so every correction and each new tax year’s rates reach your page without you changing anything.

Will it slow my page down?

The frame loads lazily, only when a reader scrolls near it, and the calculator runs in the reader’s browser.

Is anything recorded about my visitors?

No analytics run inside the frame, and it shows no cookie banner, chat button or sign-up prompt. Links inside a calculator open in a new tab, so your page stays where it is.

Can I change the colours or the wording?

Not yet. Every calculator uses the same neutral light design, which is built to sit on most sites.

If you let property yourself

The calculators are the small part

LetCompliance runs the whole let: the advert, the tenant checks, the tenancy, Direct Debit rent with no commission, the repairs, the certificates and the tax, recognised by HMRC for Making Tax Digital.

Get started See everything it does