UK SIPP Calculator
Self-Invested Personal Pension: pot growth plus HMRC tax relief on your contributions.
Inputs
How it works
Monthly compounding · end-of-period contributions. HMRC adds 20% basic-rate relief at source; higher/additional-rate taxpayers reclaim the extra via Self Assessment. Contributions above the annual allowance (£60,000) may face a charge.
Frequently asked questions
Is this guaranteed?
No — these are projections that assume your inputs hold. Real markets and life are variable.
What's the 4% safe-withdrawal rule?
The Trinity Study suggests withdrawing 4% of a balanced portfolio in year one and adjusting for inflation typically lasts 30+ years.
Should I max out my 401(k)?
At minimum, capture the full employer match — that's free money. Beyond that, balance against debt payoff and emergency reserves.
Roth vs. Traditional?
Roth wins if you'll be in a higher tax bracket in retirement; Traditional wins if you'll be in a lower bracket.
When should I start saving?
Immediately. The single biggest variable in retirement success is years of compounding.