Let to buy can be a very complicated process, and we recommend that you use the calculator as reference only, before talking to our. . Terms from 2 to 5 years. Our remortgage calculator will be able to give you a guide as to what your new repayments could work out at, once you've completed your mortgage buyout. Remortgage calculators use up-to-date interest rates (according to the latest loan-to-value ratios), the property's current value, remaining mortgage amount, term, and existing monthly payments. . Why not use our equity release calculator to see how much you could release.