Find out when you can retire and how much you'll have — US & UK
🇺🇸 US: Uses the 4% safe withdrawal rule. Social Security is factored in as guaranteed income. Enter your 401(k)/IRA balance and contributions to see if you're on track.
🇬🇧 UK: The full new State Pension (2025/26) is £11,973/year, paid from age 66. Enter your workplace pension, ISA, or SIPP savings. The calculator uses the 4% rule to determine if your pot is large enough alongside your State Pension.
Projections assume constant returns. Actual investment performance varies. Consult a financial adviser for personalised retirement planning.
The 4% rule (also called the safe withdrawal rate) states that you can withdraw 4% of your retirement savings in the first year, then adjust for inflation each year, and your portfolio should last at least 30 years. So to replace £30,000/year of income, you need approximately £750,000 saved (£30,000 ÷ 0.04). It's a useful starting point, though some financial planners now recommend a more conservative 3–3.5% for longer retirements.
A common rule of thumb is to save 25× your expected annual retirement spending (which is derived from the 4% rule). If you plan to spend £25,000/year in retirement, you'd need £625,000. This assumes state pension or Social Security supplements your withdrawals. Use this calculator to find your personal number based on your age, income, and existing savings.
In the UK, you can access your pension savings from age 55 (rising to 57 in 2028). State Pension begins at age 66. In the US, you can access 401(k) and IRA funds penalty-free from age 59½. Social Security benefits can begin as early as 62 (at a reduced amount) or as late as 70 (at a higher amount). Early withdrawal usually incurs a 10% penalty plus income tax.
A defined benefit (DB) pension guarantees a specific income in retirement based on your salary and years of service — the employer bears the investment risk. A defined contribution (DC) pension builds up a pot of money based on contributions and investment returns — you bear the investment risk. Most private sector pensions are now DC. State/government employees often still have DB schemes.
Always contribute enough to get your full employer pension match first — it's an instant 50–100% return. After that, focus on high-interest debt (above 6–7% interest rate) before investing more, since the guaranteed return of paying off debt likely exceeds investment returns. For low-interest debt (mortgages, student loans), investing often wins mathematically due to compound growth over time.
UK State Pension figures from GOV.UK New State Pension. US figures from the Social Security Administration.
Figures are estimates for guidance only. See about this site — how we source data and what these tools can and cannot do.
The 4% rule emerged from the Trinity Study (1998), which analysed historical US stock and bond market returns to find a "safe withdrawal rate" — the percentage of a portfolio you could withdraw annually with a high probability of the money lasting 30 years. The research found that a 60/40 portfolio (60% stocks, 40% bonds) survived all 30-year historical periods when withdrawals started at 4% of the initial value, adjusted for inflation each year.
The limitation is that the study used US market data from 1926–1995 — a period that included exceptional long-term returns. Some researchers argue a 3–3.5% rate is more appropriate given current low bond yields and higher equity valuations. Others argue the 4% rule remains valid as a starting point for a 30-year horizon but is too aggressive for longer retirements (40+ years), early retirees, or portfolios with high equity exposure.
For planning purposes: the 4% rule tells you how large a pot you need to generate a given income. To replace £30,000/year, you need approximately £750,000 (£30,000 ÷ 0.04). The State Pension or Social Security reduces the amount you need to draw from your personal savings.
The full new State Pension for 2025/26 is £11,973 per year (£230.25 per week). To receive the full amount, you need 35 qualifying years of National Insurance contributions or credits. You need a minimum of 10 qualifying years to receive any State Pension. The State Pension age is currently 66, rising to 67 between 2026 and 2028, and expected to rise further to 68 after that.
State Pension income counts toward your income tax personal allowance (£12,570 for 2025/26). Since the full State Pension (£11,973) is just below the personal allowance, most people receive the State Pension entirely tax-free, though any additional pension or employment income above the threshold is taxable.
You can check your State Pension forecast and NI record on the government's online service (gov.uk/check-state-pension). Gaps in your NI record from periods of unemployment, self-employment, or time abroad can often be filled by making voluntary Class 3 NI contributions — currently £17.45 per week for 2025/26.
The 2025 contribution limit for a 401(k) is $23,500 ($31,000 if aged 50+). For Traditional and Roth IRAs, the limit is $7,000 ($8,000 if aged 50+). Contributions to a Traditional 401(k) or Traditional IRA reduce your taxable income in the contribution year; Roth accounts are funded with after-tax money but grow and are withdrawn tax-free.
Social Security retirement benefits are calculated from your highest 35 years of earnings. The full retirement age for those born in 1960 or later is 67. Claiming early (from 62) permanently reduces benefits by up to 30%. Delaying to 70 increases benefits by 8% per year beyond full retirement age — the most reliable guaranteed return available to most Americans.
UK State Pension figures are from DWP 2025/26 published rates. The 4% withdrawal rate follows the Trinity Study (Cooley, Hubbard, Walz, 1998). US contribution limits are IRS 2025 published figures. Social Security benefit calculation methodology follows SSA guidelines. All projections assume constant real returns — actual investment performance varies. Consult a financial adviser for personalised retirement planning.
Researched and maintained by Iulian, founder of Flux Media Systems. General information, not professional advice — about this site & our sources →