Retirement Savings Calculator

The 4% Rule

The 4% rule is a widely-cited guideline for how much you can sustainably withdraw from a retirement pot without running out of money. It suggests withdrawing 4% of your pot in the first year of retirement, then increasing that amount with inflation each subsequent year. The figure comes from US research (the 'Trinity Study') showing that, historically, a portfolio of shares and bonds had a high probability of lasting at least 30 years at this withdrawal rate. A practical implication: to generate £20,000 a year, you'd need a pot of around £500,000 (since £20,000 is 4% of £500,000). Flip it around and the rule becomes a target — multiply your desired annual income by 25 to estimate the pot you need. However, the rule has important caveats. It was based on historical US market returns and a 30-year horizon, so it may be too aggressive for early retirees needing the money to last longer, or in periods of low expected returns. It assumes a particular investment mix and ignores fees, taxes, and the 'sequence of returns' risk (a market crash early in retirement is far more damaging than one later). Many advisers now treat 3-3.5% as more cautious, or use flexible strategies that adjust withdrawals when markets fall. Treat the 4% rule as a useful rule of thumb for setting a savings target, not a precise withdrawal plan.

State Pension

The UK State Pension forms the foundation of most people's retirement income, and it's essential to factor it in when working out how much private saving you need. The full new State Pension is around £11,500 a year (2026/27), paid to those who reach State Pension age with a full National Insurance (NI) record — generally 35 qualifying years of contributions or credits. Fewer years means a proportionately reduced amount, with a minimum number of years (usually 10) needed to get anything at all. You can check your forecast and NI record through the government's online service, and in some cases fill gaps by paying voluntary contributions — which can be remarkably good value if you're short of qualifying years. The State Pension age is rising (currently 66, moving to 67 and then 68 for younger people), so check yours, as it affects when this income starts and therefore how long your private savings must bridge. The State Pension is also subject to the 'triple lock', meaning it rises each year by the highest of inflation, average earnings growth, or 2.5% — historically helping it keep pace with or beat inflation, though policy can change. Because the State Pension covers a meaningful chunk of basic needs, your private pension and savings only need to top up to your desired lifestyle, not provide the whole amount — which significantly reduces the pot many people assume they need.

Inflation in Retirement

Inflation is the quiet threat to a long retirement, and ignoring it is one of the biggest planning mistakes. A pension income that feels comfortable at 65 can lose much of its purchasing power by 85: at 3% annual inflation, prices roughly double over 24 years, so £20,000 a year would buy what £10,000 does today after a couple of decades. This is why a fixed, level income that never rises gradually erodes your standard of living. To protect against it, your retirement income needs to grow over time. Options include keeping part of your pot invested through retirement (so it can grow), choosing an inflation-linked annuity if buying one (though these start at a lower income than level annuities), and benefiting from the State Pension's triple lock. The 4% rule itself builds in inflation increases, which is why it's more cautious than simply taking 4% flat each year. Healthcare and care costs, which often rise faster than general inflation and tend to increase late in life, deserve particular thought. When using this calculator, bear in mind that a pot projection in today's money is more meaningful than a future-value figure that looks large but buys less — and that the income you target should be one that can rise over a retirement that might last 30 years or more. Building in annual increases, rather than planning around a flat figure, is the safer approach.

When to Seek Financial Advice

Calculator results provide estimates based on stated inputs and should not replace professional financial advice for significant decisions. Free, regulated financial guidance is available through MoneyHelper (moneyhelper.org.uk, 0800 011 3797) for general money queries. Regulated independent financial advisers (IFAs) — find one at unbiased.co.uk — provide personalised advice on mortgages, pensions, investments, and insurance. Advice fees are typically £150-350 per hour or a percentage of assets