Yes, a mortgage calculator can give you a rough estimate of how much you might borrow and what your monthly repayments could be before you apply. It is not a mortgage offer, and the amount a lender may approve depends on your income, outgoings, deposit, credit history and its affordability checks. When you make an online application, you may need documents such as payslips, bank statements and proof of identity. Compare calculators carefully and consider speaking to an FCA-authorised mortgage adviser if you need help understanding your options.