This calculator models an existing Help to Buy equity loan — the UK government scheme that lent first-time buyers up to 20% (40% in London) of a new-build property's value, interest-free for the first five years. The scheme closed to new applicants in England and Scotland on 31 October 2022, with all approved purchases required to complete by 31 March 2023, so this calculator is for tracking a loan you already have rather than applying for a new one (Wales ran its own separate version, due to close in September 2026). It projects how your loan balance changes as your property value grows, since the amount you owe is always a percentage of the current value rather than a fixed sum, then shows how interest builds from year six onwards and what repayment could look like depending on when and how you plan to pay it off — whether that's a set year, alongside your main Mortgage, or funded from savings or an ISA. If you're saving toward a deposit as a new buyer rather than repaying an existing Help to Buy loan, the Lifetime ISA calculator covers the 25% government bonus still available to first-time buyers, and our First-Time Buyer's Guide covers what's actually available to new buyers today.