Drawdown Calculator
Estimate how long a pot could last if you take regular withdrawals. It is a simple projection, not a drawdown recommendation.
Enter your drawdown figures
This is a straight-line projection using the same growth assumption each year. Real withdrawals can be affected by tax, fees, inflation, market falls and changing spending needs.
Your drawdown estimate
Your result will update as you change the figures.
Save or share this scenario
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Year-by-year drawdown
See the estimated pot value after withdrawals each year.
| Year | Withdrawn that year | Total withdrawn | Estimated pot |
|---|
Understanding the drawdown calculator inputs
The calculator above models how long a pot could last when you take regular withdrawals. Three inputs do most of the heavy lifting.
Starting pot
What you have when drawdown begins. Combine pensions, ISAs and any other investments you'll draw from.
Monthly withdrawal
The amount you'll take each month. The calculator shows how long the pot can sustain it under your chosen growth rate.
Growth rate
What you expect the remaining pot to earn each year. Lower is more cautious; sensible when you're testing worst cases.
Inflation increase
Whether withdrawals rise with inflation. Real life usually means yes; your spending power should keep up with prices.
The 4% rule, briefly
You'll see this rule of thumb a lot. It's a useful starting point; and a frequently misunderstood one.
The "4% rule" came from a 1990s US study that looked at historical market data and asked: what's the highest withdrawal rate that would have lasted 30 years in every historical period? The answer was roughly 4% of the starting pot, adjusted upward each year for inflation.
That's it. It's not a law, it's not guaranteed, and it was based on US stocks and bonds in a specific period. Many planners now suggest 3-3.5% for longer retirements or more cautious portfolios, while flexible withdrawal strategies can sometimes support higher rates. Use it as a sanity check, not a recipe.
How long different withdrawal rates could last
Starting pot of £500,000, 5% annual growth, inflation-linked withdrawals at 2.5% a year. Illustrative only.
| Initial withdrawal rate | Year-one withdrawal | Approximate pot lifespan |
|---|---|---|
| 3% | £15,000/year (£1,250/mo) | 40+ years |
| 4% | £20,000/year (£1,667/mo) | ~30 years |
| 5% | £25,000/year (£2,083/mo) | ~22 years |
| 6% | £30,000/year (£2,500/mo) | ~17 years |
| 7% | £35,000/year (£2,917/mo) | ~14 years |
Real markets don't deliver smooth 5% returns. Add a margin for safety; particularly in the early years of drawdown when sequence risk matters most.
Sequence of returns risk
This is the single most important concept that smooth-growth calculators don't capture.
Two retirees can earn the same average return over 20 years and end up in very different places. If one happens to retire just before a market crash, they're forced to sell more units of their fund early on to fund the same income; leaving less capital to recover when markets bounce back.
The same withdrawal rate that works fine after a strong opening decade can deplete a pot if the bad years come first. This is why many planners suggest keeping 1-2 years of expected withdrawals in cash, drawing from that during market downturns, and being prepared to flex spending in poor years.
UK tax on pension drawdown
The calculator above shows gross withdrawals. Tax can meaningfully change what you actually receive.
The 25% tax-free lump sum
UK pensions usually allow 25% to be taken tax-free (subject to the Lump Sum Allowance). You can take it as one lump or spread across withdrawals.
Income tax on the rest
The remaining 75% is taxed as income at your marginal rate when you draw it. Large lump sums can push you into a higher tax band that year.
State Pension stacks on top
Once State Pension starts, it counts toward your taxable income, which can change how much of your pension drawdown is taxed.
Drawdown timing; particularly the choice of when to take the tax-free lump sum; can affect total tax paid over retirement. This is one of the areas where regulated advice often pays for itself.
Common drawdown calculator mistakes
Drawdown is the area of financial planning where assumptions matter most. These are the usual stumbles.
Ignoring tax
A £30,000/year withdrawal isn't £30,000 in your bank account. Model the net figure once tax is taken.
Forgetting inflation
A withdrawal that feels comfortable today won't feel that way in 15 years if it doesn't rise with prices.
Assuming smooth returns
Real markets don't deliver 5% every year. Stress-test with lower rates to see how robust the plan is.
Underestimating longevity
A 65-year-old in the UK has a meaningful chance of living to 90+. Plan for the pot to last longer than the average.
Drawing too aggressively early
Front-loading withdrawals when the pot is largest sounds tempting but it's where sequence-of-returns risk does the most damage.
Forgetting the State Pension
State Pension can cover a meaningful share of essential spending. Knowing when it kicks in helps you plan pension withdrawals around it.
Drawdown Calculator FAQs
The questions that come up most often when modelling withdrawals from a pension or investment pot.
What is the 4% rule?
A historical rule of thumb suggesting 4% of the starting pot (rising with inflation) had a high chance of lasting 30 years in past US data. It's a starting point, not a guarantee.
Does the calculator handle tax?
No; withdrawals shown are gross. In the UK, 25% of a pension is usually tax-free; the rest is taxed at your marginal rate.
What growth rate should I use?
Lower than you might use for accumulation. Retirees typically hold a more cautious mix and need to weather downturns without selling at the worst moment. 3-5% is a reasonable range to test.
Should I plan for inflation-linked withdrawals?
Yes, usually. Spending power matters more than headline pounds; flat withdrawals get steadily smaller in real terms.
Tax and official tools
The pot and withdrawal figures are shown before income tax. In drawdown, usually only 25% of the pot is tax-free and the rest is taxed as income when you take it, so your spendable amount will be lower than the headline.
Sources used for this calculator:
Where your pot is managed
How a pot is drawn depends partly on where it is held and what it costs in retirement. The Knowledge Hub covers choosing a SIPP provider and consolidating old pension pots.
Sources, assumptions and review date
Last reviewed: 19 May 2026. This calculator is a simple drawdown projection based on your chosen return and withdrawal assumptions.
It does not model income tax, sequence-of-returns risk, inflation, platform fees, pension scheme rules, annuity rates or State Pension income. For pension allowances and limits, check GOV.UK pension scheme rates.