The only UK calculator that properly models Early Repayment Charges, the 10% annual allowance and rate changes. Results update instantly as you type. No sign-up, no selling, no small print.
Drag, type or tweak. Results update as you go.
Bank calculators give you a best-case fantasy. We model what actually happens to your money, penalties and all.
Every other calculator openly ignores ERCs. Ours flags when you'd breach the 10% cap and shows the penalty in pounds. Read our full guide to early repayment charges for the detail.
Real mortgages don't stay at one rate for 25 years. Model what happens when your fix ends and you remortgage. Also see our remortgage break-even tool.
Most lenders default to cutting your monthly payment. That's usually the wrong choice. Our term-vs-payment guide explains why.
Compare overpaying side-by-side against a cash ISA, a stocks & shares ISA, or a pension. Sometimes the smart move isn't to overpay at all.
We list the overpayment rules, annual allowances and typical ERCs for Nationwide, Halifax, Santander and every other major UK lender on one page.
Our maths matches industry-standard amortisation to the penny. See our methodology or read the assumptions we make.
We checked every major UK mortgage overpayment calculator. Here's what's missing from each.
Every big overpayment question deserves its own properly built tool. Here are the ones other calculators skip.
Six pillar guides, each written to actually help you decide, not to upsell you on a product.
How the annual overpayment allowance works, including the rolling-window quirk most articles miss.
When ERCs trigger, how they're calculated, and worked examples showing real pound costs.
The situations where overpaying is actively the wrong move, and what to do instead.
Why the default lender choice often loses you thousands, and how to switch it.
How offset works, when it beats a normal overpayment, and who they're really for.
Monthly, annual lump sum, round-up, offset, remortgage-then-overpay and more, side by side.
Allowances, penalties and the quirks each lender buries in their T&Cs.