FAQ
Frequently Asked Questions
Quick answers to the questions we get asked most about our calculators, our data, and how the Site works. If you can’t find what you’re looking for here, take a look at our How It Works page, or get in touch.
About Our Calculators
Are the calculators free to use?
Yes — every calculator on this Site is completely free. There is no registration, no subscription, and no hidden charges to get a result.
How accurate are the results?
Our calculators use published UK rates and thresholds — including HMRC income tax bands, National Insurance rates, and Stamp Duty Land Tax thresholds — updated for the 2026/27 tax year. Results are estimates based on simplified, standard assumptions, and are accurate for typical situations. For non-standard circumstances (multiple incomes, self-employment, complex tax affairs), always confirm figures with HMRC, a lender, or a qualified adviser.
Do the results count as financial or mortgage advice?
No. Every result is an estimate for general information and planning purposes only — it is not financial, mortgage, tax, or legal advice, and does not constitute a mortgage offer or insurance quotation. See our Disclaimer for full detail. For significant decisions, always speak to a qualified, FCA-regulated adviser.
Which tax year do the calculators use?
Our tax, salary and Stamp Duty calculators are updated for the 2026/27 UK tax year (6 April 2026 to 5 April 2027), including separate Scottish income tax bands where applicable.
Why does my mortgage calculator result differ from a lender’s illustration?
Our Mortgage Calculator uses the same standard amortisation formula lenders use, but a real lender illustration also factors in your specific product rate, any fees added to the loan, and their own rounding conventions. Small differences are normal — use our figures as a guide, then confirm exact numbers with your lender or mortgage adviser.
Privacy and Your Data
Do you store the figures I enter into a calculator?
No. Every calculation runs directly in your web browser using JavaScript. The numbers you enter — income, property price, mortgage balance, and so on — are never sent to, or stored on, our servers.
Do you use cookies?
We use a limited number of cookies to run the Site and, where enabled, to understand aggregate usage through analytics. See our Cookie Policy for full details and how to control them.
Is my data shared with anyone?
We do not sell or share personal data with third parties for their own marketing purposes. See our Privacy Policy for full details on what we collect and why.
Technical
Do the calculators work on mobile?
Yes — every calculator is fully responsive and works on smartphones, tablets and desktop browsers alike.
Why is a result showing as £0 or blank?
Most calculators require the required fields (marked on the form) to be filled in with a valid, positive number before they will calculate a result. Double-check you have entered a value in every required field.
I think I’ve found an error — what should I do?
Please let us know via our Contact page, including the calculator name, the figures you entered, and the result you received, so we can look into it.
About This Site
Who runs Kleinfeld Mortgage Calculators?
Kleinfeld Mortgage Calculators is an independent website providing free UK mortgage, property and money calculators. We are not affiliated with HMRC, the FCA, or any government body, lender, or insurer.
Are you regulated to give financial advice?
No — we are not authorised or regulated by the Financial Conduct Authority (FCA), and nothing on this Site is a personal recommendation. Our calculators are tools for general guidance only. See our Disclaimer.
How do I contact you?
Via our Contact page.