UK Personal Finance Calculator 2026

Mortgage · Pension · ISA · LISA

Compare all four options side by side — including tax relief, employer matching, government bonuses, ISA allowances, and inflation-adjusted real returns.

⚙️ Your Details
🏠 Mortgage
£
0.10%15.00%
%
yrs
mo
£0£2,000
£
🧾 Tax & Income
£0£300k
£
📈 Time Horizon
5 yrs40 yrs
yrs
💼 Pension
Pension type
Auto-enrolment: You contribute from net pay. HMRC adds 20% basic rate relief at source. Higher/additional rate taxpayers reclaim extra via Self Assessment. Employer must contribute at least 3% of qualifying earnings.
Employee contribution
0%30% of salary
%
£0£5,000/mo
£
0%15% of salary
%
Employee: — Employer: — Total into pot: —
£0£500k
£
1% cautious15% aggressive
%
Current winner
—
|
📊 Results
🏠 Mortgage
—
Interest saved
💼 Pension
—
Pot at retirement
📦 ISA
—
Tax-free pot
🎁 LISA
—
With gov bonus
🏆 Winner
—
by this margin
⚖️
Calculating...
💬 What this means for you
Enter your details above and we'll explain your results in plain English.
📉 Mortgage Rate Change Impact
See exactly how your monthly payment and total interest change if your rate moves — useful when remortgaging or stress-testing your finances.
Your current rate: 4.50% Monthly payment: —
4.50%
0.10%15.00%

Based on your remaining balance and term above. Assumes capital repayment mortgage. For illustration only.

Comparison Chart
Full Breakdown Table
Factor 🏠 Mortgage 💼 Pension 📦 ISA 🎁 LISA
Interest Saved
—
By overpaying monthly
Term Reduced
—
Years knocked off
Monthly Payment
—
Standard repayment
Guaranteed Return
—
Risk-free equivalent
💡 Overpaying your mortgage gives a guaranteed, risk-free return equal to your interest rate. At high rates (5%+) this often beats cautious investments after tax. Most lenders allow up to 10% overpayment per year without early repayment charges — check your terms.
Total Pension Pot
—
At retirement
Tax-Free Lump Sum
—
25% (up to £268,275)
Net Monthly Cost
—
After tax relief
Free Money/Year
—
Relief + employer match
🌱 Existing Pot Grown To
—
Your current pot compounded at stated return
➕ New Contributions Add
—
From ongoing monthly contributions
💡 Higher-rate taxpayers reclaim an extra 20% via Self Assessment on top of the 20% added at source. Combined with employer matching, the pension is typically the most powerful wealth-building tool available. Funds are locked until age 57 (rising from 55 in 2028).
Total ISA Pot
—
Fully tax-free growth
Real Value (Inflation)
—
Purchasing power today
Annual Contribution
—
Of £20,000 annual limit
Total Growth
—
Gain above new contributions
🌱 Existing Pot Grown To
—
Your current ISA compounded at stated return
➕ New Contributions Add
—
From ongoing annual contributions
💡 Stocks & Shares ISAs offer fully flexible access — withdraw any time with no tax on gains or dividends. Annual allowance is £20,000 across all ISA types combined. No employer match or tax relief, but no lock-in. Your LISA contributions count toward this £20,000 limit.
Total LISA Pot
—
With government bonus
Government Bonus
—
25% on up to £4,000/yr
Bonus Years Left
—
Until age 50 cutoff
Real Value
—
Inflation-adjusted
🌱 Existing Pot Grown To
—
Your current LISA compounded at stated return
➕ New Contributions Add
—
From ongoing contributions + bonus
💡 LISA Rules: Max contribution is £4,000/year (max £1,000/yr government bonus). Must be opened before age 40. Contributions accepted until age 50. Withdraw penalty-free only for: (1) purchasing your first home (max value £450,000), or (2) retirement from age 60. Any other withdrawal incurs a 25% penalty — which costs you more than your bonus. LISA contributions count towards your £20,000 annual ISA allowance.
Pension — Nominal
—
At stated return rate
Pension — Real
—
Purchasing power today
ISA — Nominal
—
At stated return rate
ISA — Real
—
Purchasing power today
LISA — Nominal
—
At stated return rate
LISA — Real
—
Purchasing power today
Mortgage Saving — Nominal
—
Interest actually saved
Mortgage Saving — Real
—
Inflation-adjusted
What inflation does to your money
💡 At 2.5% inflation, £100,000 today is worth only £78,120 in purchasing power in 10 years. Your returns need to beat inflation. Pensions and ISAs invested in global equities have historically returned 4–6% above inflation over the long run, but past performance is no guarantee.

⚠️ For illustrative purposes only — not financial advice. ISA annual allowance: £20,000 across all ISA types (S&S ISA + LISA combined cannot exceed this). LISA: max £4,000/yr contribution, max £1,000/yr government bonus, open age 18–39, contributions until 50, access at 60+ or for first home ≤£450,000. Unauthorised LISA withdrawals incur a 25% penalty. Pension access age rising to 57 in 2028. Tax-free pension lump sum capped at £268,275. Consult a qualified FCA-regulated financial adviser before making decisions.

Learn More

Guides & Articles

Plain-English guides on mortgages, pensions, ISAs and LISAs — helping you make smarter decisions with your money.

💼 Pension 11 articles
Pension
UK Pension Guide 2026: Tax Relief, Employer Matching & How Much to Contribute
How pension tax relief works at every tax band, why employer matching is free money you should not leave behind, and how much to put in at every age.
Read article →
 Pension
Pension vs ISA: Which Is Better for Retirement Saving?
Tax relief on the way in vs tax-free on the way out — a detailed breakdown of when the pension wins, when the ISA wins, and why most people should use both.
Read article →
 Pension
How Much Should I Have in My Pension at 30? UK Benchmarks 2026
The honest benchmarks for age 30, what most people actually have, and why the decisions you make this decade compound more powerfully than any other. Real numbers.
Read article →
 Pension
How Much Should I Have in My Pension at 40?
Are you on track? The UK benchmarks, how to calculate what you actually need, and exactly what to do if you are behind at the most important pension checkpoint.
Read article →
 Pension
What Happens to My Pension When I Change Jobs?
Your pension does not disappear — but you have important choices. Leave it, transfer it, or consolidate into a SIPP. Here is what to consider and what to avoid.
Read article →
 Pension
What Is Salary Sacrifice and How Much Does It Save You?
Salary sacrifice saves income tax AND National Insurance on your pension. Here is how it works, the real monthly saving, and whether it is always better than standard contributions.
Read article →
 Pension
Best SIPP for Self-Employed UK 2026
No employer pension? Here are the best SIPPs for self-employed people — with tax relief, fees and consolidation compared.
Read article →
 Pension
Best SIPP Providers UK 2026
Hargreaves Lansdown, AJ Bell, Vanguard, PensionBee and Nutmeg compared — which SIPP is right for you depends on fees, choice and your situation.
Read article →
 Pension
Pension vs ISA for Higher Rate Taxpayers UK
At 40% tax the pension advantage is decisive — but the ISA still has a vital role. Here is the maths and the optimal strategy.
Read article →
 Pension
How Pension Tax Relief Works in the UK
Relief at source, net pay, salary sacrifice — explained in plain English with real numbers at every tax band. Plus how to claim back what you are owed.
Read article →
 Pension
Salary Sacrifice and Student Loans: The Hidden Saving
Salary sacrifice reduces your student loan repayment as well as your tax and NI. Most people do not know this — here is exactly how much you could save across every repayment plan.
Read article →
🏠 Mortgage 3 articles
Mortgage
How Mortgage Overpayments Work in the UK
The 10% rule, early repayment charges, how much interest you actually save, and whether it is worth doing in 2026.
Read article →
 Mortgage
Does Overpaying Your Mortgage Affect Your Credit Score?
The surprising truth about mortgage overpayments and credit files — busting common myths and explaining what lenders actually see.
Read article →
 Mortgage
When Should I Remortgage? Getting the Best Deal in 2026
How early to start, the 2 vs 5 year fix decision, the costs involved, and the single biggest remortgaging mistake UK homeowners make.
Read article →
📦 ISA 5 articles
ISA
ISA vs LISA: Which Is Better for Your Savings?
A clear comparison of the Stocks & Shares ISA and Lifetime ISA — when the 25% LISA bonus genuinely wins, and when ISA flexibility matters more.
Read article →
 ISA
Best Stocks & Shares ISA UK 2026
The best ISA providers compared on fees, fund choice and long-term value — with a 20-year fee impact table showing what each actually costs you.
Read article →
 ISA
What Is a Stocks & Shares ISA? UK Beginners Guide
What you can invest in, how the tax wrapper works, how it compares to a Cash ISA, pension and LISA — everything a beginner needs to know.
Read article →
 ISA
The Annual ISA Allowance UK 2026: Everything You Need to Know
How the £20,000 ISA allowance works, which ISAs count toward it, the LISA sub-limit, and how couples can use it to shelter £40,000 a year tax-free.
Read article →
 ISA
ISA Deadline 2026: Use Your £20,000 Allowance Before April 5th
The ISA deadline is April 5th — after that this year's £20,000 allowance is gone forever. Who should act, what to prioritise, and whether a pension beats an ISA this year.
Read article →
🎁 Lifetime ISA (LISA) 6 articles
LISA
What Is a Lifetime ISA and Is It Worth Opening One?
Everything about the LISA — the 25% bonus, who qualifies, the withdrawal rules, and whether it is the right move for first-time buyers and retirement savers.
Read article →
 LISA
LISA for First-Time Buyers: Is the 25% Bonus Worth It?
The rules, the real numbers, and how to use a Lifetime ISA to boost your first home deposit — including what happens if your plans change.
Read article →
 LISA
Can I Have Both a LISA and a Workplace Pension?
Yes — and using both together is often smarter than either alone. How the LISA and pension complement each other for a tax-efficient retirement strategy.
Read article →
 LISA
Best Lifetime ISA Providers UK 2026
AJ Bell, HL, Moneybox, Wealthify and Nutmeg compared on fees, fund choice and ease of use — so you can open the right LISA today.
Read article →
 LISA
How to Open a Lifetime ISA: Step-by-Step Guide
Everything you need to open a LISA today — rules, which provider to choose, how to set up the monthly contribution and when your first bonus arrives.
Read article →
 LISA
ISA vs LISA for First-Time Buyers UK 2026
When does the LISA 25% bonus beat a standard ISA for your deposit — and when does the ISA flexibility win? An honest breakdown for first-time buyers.
Read article →
📋 Comparisons & Guides 5 articles
All Options
Should I Overpay My Mortgage or Invest?
The definitive guide to one of the most common UK financial dilemmas — when each option wins, and how your tax band changes the answer.
Read article →
 Retirement
How to Save for Retirement in Your 30s: The Complete UK Guide
Your 30s are the most important decade. The right order of priorities — pension, LISA, ISA, mortgage — and how compound growth makes starting now so powerful.
Read article →
 Comparison
Vanguard vs Hargreaves Lansdown UK 2026
Two of the UK most popular platforms compared honestly — fees, fund choice, products and which type of investor each one suits.
Read article →
 Comparison
AJ Bell vs Hargreaves Lansdown UK 2026
Fees, fund choice, dealing costs and usability compared — which of the UK two biggest investment platforms is right for you?
Read article →
 Tax
New Tax Year 2026/27: Every Change That Affects Your Money
From 6 April 2026: State Pension up 4.8%, dividend tax rising, income tax thresholds frozen. Here is what actually changes and what to do about it.
Read article →