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GrowThenDraw Updated for 2026/27

UK Investment Withdrawal Calculator

Project monthly withdrawals, how long your investments may last, and estimated 2026/27 tax from a GIA or Stocks & Shares ISA.

Published by GrowThenDraw Editorial Team · Editorial policy · Methodology & sources

Your plan

Tip: set this to your inflation assumption (~2.5%) to keep your withdrawals' buying power constant.

7% — FTSE 100 long-run average, editable

Income after your Personal Allowance and other Income Tax reliefs. After the £3,000 gain exemption, gains use the remaining £37,700 basic-rate band at 18%, then 24%.

Advanced: cost basis

Your total contributions (cost basis). Only the growth above this is taxed as you withdraw.

Net monthly payout, year 1 (after tax)
£2,313
Lasts all 30 years with money left over
Total received (net)
£781,723
Total tax
£118,277
Ending balance
£990,530

The most this plan can sustain for the full 30 years: £3,307/month before tax.

£495.3k£990.5kYear 1: balance £504,983, net income £27,756Year 2: balance £510,326, net income £27,579Year 3: balance £516,055, net income £27,415Year 4: balance £522,199, net income £27,261Year 5: balance £528,786, net income £27,118Year 6: balance £535,850, net income £26,985Year 7: balance £543,425, net income £26,861Year 8: balance £551,547, net income £26,721Year 9: balance £560,256, net income £26,577Year 10: balance £569,595, net income £26,443Year 11: balance £579,608, net income £26,317Year 12: balance £590,346, net income £26,200Year 13: balance £601,860, net income £26,091Year 14: balance £614,206, net income £25,989Year 15: balance £627,445, net income £25,895Year 16: balance £641,641, net income £25,806Year 17: balance £656,863, net income £25,724Year 18: balance £673,186, net income £25,647Year 19: balance £690,688, net income £25,575Year 20: balance £709,456, net income £25,508Year 21: balance £729,580, net income £25,445Year 22: balance £751,160, net income £25,387Year 23: balance £774,299, net income £25,333Year 24: balance £799,111, net income £25,282Year 25: balance £825,716, net income £25,235Year 26: balance £854,245, net income £25,191Year 27: balance £884,837, net income £25,150Year 28: balance £917,639, net income £25,112Year 29: balance £952,813, net income £25,076Year 30: balance £990,530, net income £25,043Y1Y6Y11Y16Y21Y26Y30
End balance
Received (net): £781,723Tax: £118,277Still invested: £990,530
Received (net)TaxStill invested
YearWithdrawnTaxNetEnd balance
1£30,000£2,244£27,756£504,983
2£30,000£2,421£27,579£510,326
3£30,000£2,585£27,415£516,055
4£30,000£2,739£27,261£522,199
5£30,000£2,882£27,118£528,786
6£30,000£3,015£26,985£535,850
7£30,000£3,139£26,861£543,425
8£30,000£3,279£26,721£551,547
9£30,000£3,423£26,577£560,256
10£30,000£3,557£26,443£569,595
11£30,000£3,683£26,317£579,608
12£30,000£3,800£26,200£590,346
13£30,000£3,909£26,091£601,860
14£30,000£4,011£25,989£614,206
15£30,000£4,105£25,895£627,445
16£30,000£4,194£25,806£641,641
17£30,000£4,276£25,724£656,863
18£30,000£4,353£25,647£673,186
19£30,000£4,425£25,575£690,688
20£30,000£4,492£25,508£709,456
21£30,000£4,555£25,445£729,580
22£30,000£4,613£25,387£751,160
23£30,000£4,667£25,333£774,299
24£30,000£4,718£25,282£799,111
25£30,000£4,765£25,235£825,716
26£30,000£4,809£25,191£854,245
27£30,000£4,850£25,150£884,837
28£30,000£4,888£25,112£917,639
29£30,000£4,924£25,076£952,813
30£30,000£4,957£25,043£990,530

Monthly withdrawals from an ISA or GIA

A regular withdrawal sells part of your investments each month and pays the proceeds to you. The calculator follows a GIA or Stocks & Shares ISA through that drawdown, showing the projected balance, gross withdrawals and estimated take-home amount.

Pension drawdown is taxed as income under different rules, so it has its own UK pension drawdown calculator. Keeping the account types separate prevents a tax-free ISA result from being confused with a taxable pension or GIA.

2026/27 CGT without a blunt band shortcut

A GIA withdrawal is partly a return of your own cost and partly a realised gain. The model uses pooled average cost, totals the gain for each projected year, deducts the £3,000 Annual Exempt Amount and stacks the remainder on the taxable income you enter.

The part within your remaining £37,700 basic-rate band is charged at 18%; any excess is charged at 24%. That means one year's gain can use both rates. A Stocks & Shares ISA switches the estimate to tax-free withdrawals. Same-day and 30-day share matching, losses, dividends, dealing fees and individual reliefs are outside this projection.

Reading the depletion chart

Green bars show your projected balance at each year's end. If withdrawals outpace growth the bars shrink and turn red in the year the pot runs out; if not, the balance can outlive the projection entirely. A step-up equal to your inflation assumption keeps your withdrawals' buying power level.

Related reading

Frequently asked questions

How long will my investment last with monthly withdrawals?

It depends on the starting balance, monthly withdrawal, investment return, charges and whether withdrawals rise over time. The calculator runs the plan month by month and shows the projected depletion date, or the remaining balance if the investment lasts through the full term.

How does the UK investment withdrawal calculator estimate CGT?

For a GIA, it estimates the gain portion using pooled average cost, deducts the £3,000 Annual Exempt Amount each projected year, then stacks the taxable gain on your taxable income. It applies 18% within the remaining £37,700 basic-rate band and 24% above it.

Can I use this for Lifetime ISA withdrawals?

No. The ISA option models an ordinary Stocks & Shares ISA, not a Lifetime ISA. Most non-qualifying Lifetime ISA withdrawals carry a 25% government charge; qualifying first-home, age-60 and terminal-illness withdrawals have separate rules that this calculator does not model.

Is this the same as pension drawdown?

No. Drawdown from a SIPP or workplace pension is taxed as income (with 25% typically tax-free) under completely different rules. This calculator models withdrawals from investment accounts — a GIA with CGT, or an ISA tax-free.

What does "originally invested" mean?

It is your cost basis: the amount attributed to buying the investments still held. The calculator uses it for a pooled-average estimate. Your platform records and HMRC share-matching rules determine the figure used on an actual disposal.

Tax figures for 2026/27 last verified 26 July 2026 against the official source — how we calculate.

GrowThenDraw is not authorised or regulated by the Financial Conduct Authority and does not provide financial advice. All results are educational estimates only — consider advice from an FCA-authorised financial adviser before acting.

Relevant bodies in this jurisdiction: FCA (financial conduct), HMRC (tax).