How this calculator works

It's a UK retirement modelling tool. You enter your current pension, ISAs, savings, salary, and target spending, and it projects year by year how the numbers evolve from your current age to your end age - accounting for income tax, National Insurance, the state pension, and standard pension drawdown rules.

The goal is to help you spot whether your plan is roughly on track, and to compare alternatives (retire earlier vs later, contribute more vs less, drain pension first vs ISA first).

No. It's an illustrative model with simplifying assumptions and doesn't know your full circumstances. The numbers it produces are only as good as the inputs you give it.

Talk to a regulated financial adviser before making real decisions about your pension or retirement plan.

2026/27. Both UK income-tax regimes are supported:

• England, Wales & Northern Ireland - standard 20% / 40% / 45% bands (default)
• Scotland - 19% / 20% / 21% / 42% / 45% / 48% bands

Pick the regime per scenario in the Tax regime dropdown on the planner. National Insurance, Personal Allowance, and the personal-allowance taper above £100,000 are UK-wide and identical in either regime.

Personal allowance is £12,570 across the UK, with the standard taper (£1 of allowance lost for every £2 earned above £100,000, fully gone at £125,140).

England, Wales & Northern Ireland (2026/27):

• Basic rate 20% up to £50,270
• Higher rate 40% up to £125,140
• Additional rate 45% above £125,140

Scotland (2026/27):

• Starter rate 19% up to £15,397
• Basic rate 20% up to £27,491
• Intermediate rate 21% up to £43,662
• Higher rate 42% up to £75,000
• Advanced rate 45% up to £125,140
• Top rate 48% above £125,140

National Insurance is UK-wide regardless of regime: 8% on employment income between £12,570 and £50,270, 2% above. State pension and pension drawdown are not subject to NI in either regime.

The LSA caps the amount of tax-free cash you can take from your pension across your lifetime at £268,275. The model tracks how much you've already used and stops generating new tax-free cash once you hit the cap.

Once exhausted, further crystallisations move money 1:1 into the taxable pot - no tax-free 25%. The "LSA used (start)" input lets you record allowance you've already used before the simulation starts.

Two ways to plan your retirement, picked via the toggle at the top of the Spending card:

• Income needed (default) - "I want £30,000 net per year. Can my pot support that?" The engine works out what to withdraw each year to hit your target after tax. Shortfall years appear if the pot can't keep up.
• Drawdown rate - "If I draw 4% of my pension at retirement (indexed by inflation each year), what income does that give me, and how long does the pot last?" Useful when you don't yet know what you'll need - many people end up with much bigger pots than they planned for because they were scared of running out.

In drawdown-rate mode, only the pension pot is touched at the rate you set. State pension is paid on top. ISA pots stay untouched as a separate buffer (you can still draw from them via manual events). The 4% rule you may have read about is exactly this mode with rate = 4: take 4% of the pot in year 1, increase by inflation each year. Excelergy's engine implements that canonical interpretation.

Switch between modes any time - the engine recomputes immediately and the chart, ledger, and tiles update.

No. Under flexi-access drawdown - the standard for most personal pensions and SIPPs since April 2015 - there's no upper limit on annual withdrawals. You can take any amount in any year, including draining the entire pot in one go if you wanted to.

The practical limits are:

• The size of your pot - the model shows shortfall years if you withdraw faster than growth.
• The Lump Sum Allowance (£268,275) - this caps the cumulative tax-free 25% portion across your lifetime, not the income you can draw.
• Income tax - withdrawals above your personal allowance are taxed at 20% / 40% / 45% (England, Wales & N. Ireland) or 19% / 20% / 21% / 42% / 45% / 48% (Scotland), just like any other income. Many retirees keep annual withdrawals below £50,270 to stay in basic-rate territory.

If you've read about a "withdrawal cap" elsewhere, three things commonly cause that confusion:

• Pre-2015 capped drawdown - had a Government Actuary's Department (GAD) limit. Abolished for new drawdowns in April 2015 but still applies to people who never converted to flexi-access.
• The "4% rule" - a planning rule of thumb (withdraw 4% of your pot in year one, increase by inflation), not a regulation. Excelergy lets you set any spending target and shows the impact year by year.
• Provider "sustainable income" calculators - suggestions, not legal caps. You can override them.

Excelergy treats annual withdrawals as uncapped and matches reality: the engine takes whatever's needed to meet your stated spending target each year, applies the correct UK tax, and tracks the LSA so you can see when tax-free cash runs out.

Uncrystallised pension is your untouched pot. When you crystallise it, the standard UK rule kicks in:

• 25% becomes tax-free cash (TFC) and you choose where it goes
• 75% moves into a crystallised pot which you draw from later as taxable income

Both pots stay invested and continue to grow inside the pension wrapper. The model treats them separately because the tax treatment differs.

A planned action at a specific age. Add one in the Event card on the planner: type, age, amount, and where the tax-free cash should go. Common uses:

• Mortgage payoff - crystallise £X at 67, send TFC External
• Build cash buffer - crystallise pre-retirement, send TFC to Cash ISA
• Move to invested pot - send TFC to Stocks ISA

You can stack multiple events at different ages. They're applied in chronological order and respect the LSA.

The 25% tax-free cash leaves the model entirely. It doesn't appear as future income, doesn't reduce your spending need, and doesn't sit in any pot. Use it for genuine one-time expenses like paying off a mortgage.

The 75% taxable portion still goes into your crystallised pension and is available for income drawdown later. The LSA tracker still ticks up by the tax-free portion.

During retirement, if you need income but your existing crystallised pot can't cover it, the model crystallises just enough uncrystallised pension to fill the gap. It uses UFPLS-style drawdown - the standard real-world approach:

• Within remaining LSA: each £1 crystallised gives 25p tax-free cash plus 75p taxable
• Beyond LSA: 100% taxable, no further tax-free cash

By default the 25% tax-free portion is delivered as part of the year's net income alongside the taxable 75% (the standard UFPLS pattern). If you'd rather model the common real-world strategy of moving that tax-free cash out of the pension wrapper, the Auto-cryst TFC setting in the Spending card (Advanced view) lets you redirect it:

• Spend as income (default) - the original UFPLS behaviour
• Cash ISA or Stocks ISA - the redirected TFC goes into the chosen ISA, capped at the £20,000 annual ISA allowance. Overflow lands in the Current Account and triggers a warning
• Current Account - parks the TFC for later use (no cap)

When TFC is redirected, the engine has to crystallise more gross to net the same income from the taxable 75% alone - you'll see the "Auto-cryst" column rise compared with the default behaviour. The "Auto-cryst" column shows the gross amount crystallised that year; it's separate from the manual events you add (those still let you direct TFC to any destination explicitly).

The redirection only applies within the Lump Sum Allowance window. Once cumulative crystallisations have used up the £268,275 LSA cap (across both auto-cryst and any manual events), beyond-LSA drawdowns have no tax-free portion - they're 100% taxable income under UK rules. From that point on there's no TFC to redirect, so the auto-cryst TFC destination setting has no further effect. The planner emits a one-off warning the year this transition happens, so you can see when it stopped applying to your scenario.

The Autumn Budget 2025 announced a structural change to how the £20,000 annual ISA allowance can be used. From 6 April 2027 (the 2027/28 tax year onwards):

• Under 65: Cash ISA contributions are capped at £12,000 per tax year. The remaining £8,000 of the £20,000 total ISA allowance must go to a Stocks & Shares ISA or Innovative Finance ISA.
• 65 and over: the full £20,000 can still be contributed to a Cash ISA.
• Total allowance: unchanged at £20,000 across all ISA types combined.
• Transfers: from April 2027 you can no longer transfer Stocks & Shares or Innovative Finance ISA funds into a Cash ISA (this stops the under-65 cap being bypassed).
• Junior ISA: unchanged at £9,000.

The 2026/27 and 2026/27 tax years are unaffected - you can still put the full £20,000 into a Cash ISA for as long as the existing rules apply. The new cap only applies to new contributions from 6 April 2027; existing balances are not retrospectively affected.

How the planner handles it:

• If you've set monthly Cash ISA contributions that would exceed £12,000/yr, a warning fires from the simulation year that the cap first bites (typically when you're under 65 in 2027/28 or later).
• If you've redirected auto-cryst TFC to a Cash ISA, the engine applies the £12,000 cap (under 65) or £20,000 cap (65+) for each year automatically. Overflow lands in the Current Account with a year-by-year warning.
• Manual crystallisation events that send TFC to a Cash ISA are not capped automatically (those are explicit user choices; split into multiple events across tax years if you want realistic limits applied).

Source: HM Treasury policy statement following the Autumn Budget 2025; effective 6 April 2027.

It controls the order in which the model funds retirement spending:

• Pension first (default) - draw on pension before ISAs. Preserves ISA tax efficiency for later years and your beneficiaries.
• ISA first - draw on ISAs before pension. Useful if you want to grow your pension as long as possible and don't mind reducing ISA tax shelter.

The State Pension and Current Account are always used first regardless - they're always available cash. Only the pension/ISA order is configurable.

By default, every figure on the planner is shown in Future £ - nominal values that grow each year with inflation, exactly as they'd appear on a future bank statement. So a £30,000 spending target at age 50 might display as ~£63,000 by age 90 after 30+ years of 2.5% inflation.

The Today's £ / Future £ toggle on the wealth-chart panel switches between the two. Today's £ deflates every value by your scenario's inflation rate so the numbers stay comparable to current money. In this view the spending line goes flat (because its growth IS inflation by definition), making it easier to see whether your real (after-inflation) wealth is keeping up.

The choice is saved in your browser, and the planner and report each remember independently. The underlying simulation is unchanged - the toggle only affects how figures are displayed.

Only in your browser's local storage. Nothing is sent to a server. The site is fully client-side - the only files served are HTML, CSS, JavaScript, and image assets.

If you clear your browser data, switch browsers, or use a different device, your scenarios won't be there. Use the Export button to back them up.

On the planner, in the Scenario card click Export. A JSON file is downloaded (excelergy-scenarios-YYYY-MM-DD.json). Save it somewhere safe.

To restore, click Import and select the file. Scenarios are merged in - existing ones with the same name are overwritten.

Same flow for moving between devices: export on one, transfer the file, import on the other.

Three fields in the Pension card capture this:

• Uncrystallised - the part you haven't touched yet
• Crystallised (start) - the value of any pot you've already moved to drawdown
• LSA used (start) - how much of the £268,275 lifetime tax-free cash limit you've already used

Get the LSA-used number from your pension provider's drawdown statement. If unsure, set it to 25% of the figure you see in "Crystallised (start)" - that's the typical ratio if your existing crystallisations were standard-rule.

Plenty of things, deliberately, to keep the model understandable:

• Tapered pension annual allowance for high earners (income £260k+)
• MPAA - Money Purchase Annual Allowance restrictions after flexible drawdown
• Defined benefit pensions and final-salary schemes
• General Investment Account (GIA) capital gains tax
• Property income / rental yields
• Annuities and care-cost annuity hybrids
• Inheritance tax planning
• Variable returns / Monte Carlo / sequence-of-returns risk

If any of these dominate your plan, this calculator will under-tell the story - talk to an adviser.

The tax bands (UK and Scottish), NI thresholds, state pension figure, LSA limit, and ISA allowance are correct for the 2026/27 UK tax year. The drawdown logic mirrors standard UFPLS pension rules and reproduces the well-known 60% (UK) and 67.5% (Scotland) effective marginal rates in the personal-allowance taper zone.

Year-on-year compounding may drift by a few pounds over decades due to floating-point arithmetic - not material.

The biggest source of error is your input assumptions: growth rates, charge, inflation, and what your salary or contributions will actually look like. The engine does what you tell it; it doesn't predict the future.