Mortgage Decoded · Free Education Tool · 12 Calculators

The Real Cost of
Your Mortgage

Discover the hidden impact of interest, explore smarter strategies, and understand exactly what you're paying — and when. Free, no sign-up, built to educate not to sell.

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Total Mortgage Cost

See the full price of your mortgage — what you pay vs. what you borrowed.

Loan vs Interest — What Makes Up Your Total Repayment
Outstanding Balance Over Time

How Your Payments Split

In the early years, most of your monthly payment goes to the bank — not your home equity.

Monthly Interest vs Capital — Each Year
Interest Paid
Capital Repaid

The Power of One Extra Payment

Making 13 payments instead of 12 each year has a surprisingly dramatic effect on your total interest and term.

ScenarioMonthlyTotal PaidTotal InterestTerm
Balance Over Time: Standard vs 13 Payments/Year
Standard (12/yr)
13 Payments/yr

2-Year vs 5-Year Fixed Rate

Remortgaging fees add up. See how product fees compound over your full term.

StrategyRemortgagesTotal FeesTotal InterestGrand Total
Cumulative Total Cost Over Term
2-Year Fixed
5-Year Fixed

Offset Mortgage vs. Investing

Should you use savings to reduce your mortgage interest — or invest for growth?

Cumulative Interest Saved vs Investment Portfolio Value
Interest Saved (Offset)
Investment Portfolio

Stamp Duty & True Buying Cost

SDLT is paid upfront and often forgotten. See the full cash needed before your first mortgage payment.

Stamp Duty Bands — How It's Calculated
Full Upfront Cost Breakdown

Rent vs. Buy Comparison

Buying isn't always better — it depends on how long you stay, how prices move, and what you do with your deposit if you rent instead.

Net Wealth Over Time: Buying vs Renting + Investing
Net Worth: Buy
Net Worth: Rent + Invest

Rate Sensitivity Tool

What happens to your payments and total cost when rates change? Essential stress-testing for any homeowner approaching renewal.

Monthly Payment vs Interest Rate Scenarios
Rate ScenarioMonthly Paymentvs CurrentExtra per YearTotal Interest

Early Repayment Charge (ERC)

Leaving a fixed deal early triggers a penalty. Find out whether switching is worth it — even after paying the ERC.

Cumulative Cost: Stay vs Switch (including ERC)
Stay on Current Deal
Pay ERC + Switch Now

Deposit Impact

A bigger deposit doesn't just reduce your loan — it unlocks better rates, lower LTV bands, and dramatically less interest over the life of your mortgage.

Rates below reflect typical LTV-tiered pricing. Click any rate to adjust it.

DepositLTVRate (%)MonthlyTotal InterestTotal Cost
Total Interest Paid by Deposit Size

Life of Loan Inflation Adjuster

Your payment stays fixed, but inflation erodes its real value. In 20 years, £1,500/month feels very different. See what it's actually worth over time.

Nominal Payment vs Real (Inflation-Adjusted) Value
Nominal (what you pay)
Real Value (today's £)
YearMonthly PaymentReal Value (Today's £)Purchasing Power LostReal as % of Nominal

SVR Danger Zone Avoid This

Falling onto your lender's Standard Variable Rate is one of the most expensive mortgage mistakes. Model the exact cost — and compare your real alternatives: fix or tracker.

ScenarioMonthlyTotal Interestvs Fix NowExit Fees?
Cumulative Interest: SVR vs Fix vs Tracker
SVR (full term)
SVR then Fix (after delay)
Fix immediately
Tracker (no exit fee)