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Find your Coast FI number --
and stop sprinting.

Coast Financial Independence is one of the most powerful — and least talked about — milestones on the road to financial freedom. It's the point where you've invested enough that, even if you never save another penny, your money will grow by itself to fully fund your retirement. You can stop pushing so hard. You can coast.

This calculator tells you exactly how close you are — and what it would take to get there.

What is Coast FI?

The point where your invested wealth will grow on its own to your retirement goal — with zero additional contributions.

Why does it matter?

Once you hit Coast FI, you only need to cover your living costs — not save for retirement too. That's real financial breathing room.

The compound effect

Time is your most powerful asset. Money invested today works for decades, turning modest savings into life-changing wealth.

Your details

Current age How old are you today?

Retirement age When do you want to stop working?

Current investments Total across ISAs, pensions, stocks, etc.

Desired annual retirement income What you'd need per year in today's money.

Expected annual return — 7% Long-run real return after inflation. 7% is a common estimate for a diversified equity portfolio.

7%

Safe withdrawal rate — 4% The % of your pot you withdraw each year in retirement. The "4% rule" is widely used as a starting point.

4%

Calculating…

FI target

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your full retirement pot

Coast FI number

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needed today to coast

Gap to Coast FI

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still to invest

Your Coast FI progress

£0 0% of Coast FI number --

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Enter your details above to see your personalised insight.

Your wealth trajectory to retirement

Projected portfolio value

FI target

What is Coast Financial Independence?

Coast FI is a milestone, not a finish line. It's the moment your invested wealth reaches a number that — left completely alone and growing at a market rate — will compound into enough to fund your retirement by the time you reach your chosen retirement age. No more contributions needed. The market does the rest.

The name comes from the idea of coasting downhill. You've done the hard work of climbing. Now you can ease off the pedals and let momentum carry you.

The Coast FI formula works backwards from your retirement goal:

Coast FI = FI Number ÷ (1 + growth rate)^{years to retirement}

Where your FI Number = Annual retirement income ÷ Safe Withdrawal Rate.

Why this is especially important for women

The data tells a clear story. On average, women in the UK earn less over their lifetimes, take more career breaks for caregiving, and retire with significantly smaller pension pots than men. This makes the compounding window — the years your money grows before you need it — one of your most valuable financial assets.

Coast FI flips the script. Instead of scrambling to save more, it asks: what if I just needed to protect what I already have? Reaching your Coast FI number, even early in your career, transforms your relationship with work. You go from needing to work to choosing to.

Three milestones to aim for

• Coast FI — You've invested enough that compound growth will handle retirement, even if you stop saving now. You only need to cover living costs going forward.
• Lean FI — Your investments generate enough to cover a stripped-back lifestyle. Freedom with frugality.
• Full FI — Your investments generate enough to fully cover your desired lifestyle, indefinitely. This is the number the 4% rule is built around.

The 4% rule — what it is and what it isn't

The 4% rule comes from the Trinity Study, a landmark piece of US research suggesting a retiree could withdraw 4% of their portfolio annually with a historically high chance of never running out of money over a 30-year retirement. It's a useful rule of thumb — not a guarantee.

For UK investors, factors like different market conditions, longer retirements (especially for women, who on average live longer), and tax treatment of ISAs and SIPPs all matter. Many UK-based financial planners suggest using 3–3.5% for a more conservative approach. Use this calculator as a guide, and get tailored advice for your situation.

How to reach Coast FI faster

• Start earlier — Every year of additional compounding dramatically reduces the Coast FI number you need to reach. A 25-year-old needs far less invested today than a 35-year-old to hit the same retirement goal.
• Use tax-efficient wrappers — Stocks and Shares ISAs and SIPPs (Self-Invested Personal Pensions) let your money grow free of UK capital gains and income tax. Maximising these is one of the highest-return moves available to you.
• Don't leave employer pension matching on the table — If your employer matches pension contributions, unclaimed matching is effectively a 100% instant return. Take every penny.
• Invest consistently, not perfectly — Regular investing through market ups and downs (pound-cost averaging) tends to outperform attempts to time the market. Consistency beats perfection every time.
• Know your number — You can't hit a target you haven't set. Your Coast FI number, updated annually, keeps you anchored to progress rather than anxiety.

Common questions

Does reaching Coast FI mean I can stop working?

Not necessarily — but it means you only need your income to cover your current living costs, not to fund your future retirement too. Many people at Coast FI choose to keep working because they enjoy it, switch to part-time, or move into lower-paid work they love. The difference is choice, not obligation.

What investment return should I use?

The default 7% is a common long-run estimate for a globally diversified equity index fund, after inflation. The UK stock market has averaged slightly less historically; global diversification (including US equities) tends to bring returns closer to this range. Be conservative — using 5–6% gives you a more cautious, resilient plan. Past performance is not a guarantee of future returns.

Should I include my pension in my current investments?

Yes — your workplace pension and any personal pensions (SIPPs) should be included in your current investments figure. They're invested assets growing over time. Just be aware that you can't access most UK pensions until age 57 (rising to 57 in 2028), so factor in any period between retiring early and being able to draw on your pension.

What about the State Pension?

The full new State Pension (2024/25) is approximately £11,502 per year, payable from age 66 (rising to 67 by 2028). If you plan to rely on it, you can reduce your desired annual retirement income by this amount — your target portfolio will be smaller. Always check your personal State Pension forecast on the government's website.

How is this different from full FIRE?

Full FIRE (Financial Independence, Retire Early) means your investments already generate enough to cover your living costs — you can quit work entirely right now. Coast FI is an earlier, more accessible milestone: your investments will get you to full FI by retirement age, but you still need to earn enough to live on in the meantime. Coast FI is often achievable a decade or more before full FI.

Ready to build your wealth plan?

Knowing your Coast FI number is the first step. Knowing how to reach it — through the right investments, tax wrappers, and habits — is where WealthSquats coaching comes in. We work with women at every stage of their financial journey to turn numbers into action.

Book a free discovery call Explore resources

This calculator is for illustrative and educational purposes only. It does not constitute financial advice.
Returns are not guaranteed and past performance is not a reliable indicator of future results.
WealthSquats — Where Women Build Wealth, Break Barriers, and Belong. © WealthSquats Ltd.

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