Will today investments coast to your retirement number without more saving?
Coast FIRE status
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Coast value at retirement
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Shortfall vs target
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The day you can stop saving for retirement
Coast FIRE is a quieter idea than full financial independence. It does not mean you can stop working. It means you have invested enough that, even if you never add another rand to your retirement pot, compounding alone will grow it to your target by the time you retire. From that point your job only needs to cover today's living costs, not tomorrow's retirement. For a lot of South Africans in their thirties and forties who have been diligent savers, this milestone arrives years before they realise, and reaching it can free up cash for a sabbatical, a career change, or simply breathing room. This tool checks whether you are already coasting.
The single calculation behind it
The maths is one line of compound growth. The tool takes what you have invested now and grows it forward to retirement at the real return you enter, with no further contributions, then compares the result to your target number. The word real is doing heavy lifting here. Because the calculator works in real, after-inflation terms, you enter your retirement target in today's rand and the growth rate net of inflation, typically a few percentage points below the nominal return your funds advertise. That keeps everything in money you can actually understand. This is a pure investment projection with no tax modelling, though it is worth knowing that a South African retirement annuity grows free of tax on interest, dividends, and capital gains inside the fund, which is why it is the natural home for coast money.
R1.5 million, 25 years from retirement
Imagine you have R1,500,000 invested today, 25 years until retirement, a 6 percent real return, and a R10,000,000 target expressed in today's money.
| Input or result | Value |
|---|---|
| Invested today | R1,500,000 |
| Grown at 6 percent real for 25 years | R6,437,806 |
| Target in today's rand | R10,000,000 |
| Shortfall on coast alone | R3,562,194 |
| Status | Not yet coasting |
This saver is not there yet. R1.5 million compounds impressively to R6.44 million, but it falls R3.56 million short of the R10 million goal, so contributions still need to continue for now. The encouraging part is how close coasting can be: had the starting pot been about R2.33 million, the same 6 percent over 25 years would reach R10 million on its own, and saving could stop. Small differences in the starting balance or the years remaining move the verdict a long way, because compounding over decades is unforgiving of, and generous to, both.
Treat the real return number with respect
The biggest mistake people make with a coast calculation is entering a nominal return as if it were real. If your fund targets 11 percent and inflation runs near 5 percent, your real return is closer to 6 percent, and using 11 percent here would overstate your future pot wildly. Be conservative. The second judgement call is the target itself: R10 million in today's rand sounds like a lot, but at a safe 4 percent drawdown it funds only about R400,000 a year before tax, so sense-check whether your number actually supports the retirement you want. Coast FIRE is a powerful psychological permission slip, but it rests entirely on assumptions you control, so revisit it every few years as your balance and the markets move.
If I am already coasting, should I really stop saving?
Coasting means you could stop saving for retirement and still hit the target, but it does not force you to. Continuing to invest builds a buffer against weaker-than-assumed returns, a longer life, or a lower drawdown. Many people who reach coast status keep saving at a reduced rate, treating the milestone as insurance rather than a finish line.
How is Coast FIRE different from regular FIRE?
Regular FIRE means your portfolio is large enough to cover your living costs now, so you can stop working entirely. Coast FIRE is an earlier and gentler stage: your portfolio is on track to be large enough by retirement age without more contributions, but you still work to pay for daily life in the meantime.