Free calculators for compound growth, ISAs, pensions, capital gains tax, and more. Run scenarios, save the results, share with the community.
These tools provide estimates for informational purposes only and do not constitute financial advice. Results are illustrative and based on assumptions — always consult a qualified financial adviser before making investment or pension decisions.
See how regular investing grows over time — with UK market benchmarks for sanity-checking your assumptions.
Long-run real returns (after inflation) for UK investors, based on 125 years of market data:
| Asset class | Real return (1900–2024) | Nominal (at 3% inflation) |
|---|---|---|
| FTSE All-Share (UK equity) | 5.5% | ~8.5% |
| S&P 500 (GBP-adjusted) | 7.0% | ~10.0% |
| UK Gilts (bonds) | 1.2% | ~4.2% |
| UK 60/40 balanced portfolio | ~4.0% | ~7.0% |
UK long-run inflation averages around 3%. Applying that to your nominal projection shows your future pot's purchasing power in today's prices.
Work out exactly how many shares to buy so a wrong trade only costs the risk you're comfortable losing.
Most professional risk frameworks keep single-trade loss below 2% of account equity. Even a disciplined 55%-win-rate trader needs this discipline: 10 losing trades at 2% compound into ~18% drawdown.
| Risk / trade | Losing streak to −20% account | Character |
|---|---|---|
| 1% | ~22 trades | Conservative |
| 2% | ~11 trades | Standard pro |
| 5% | ~5 trades | Aggressive — fragile |
FCA retail data shows the average UK retail account holds 3–5 positions — meaning each position is ~20–33% of capital. Concentration amplifies both wins and account-killing drawdowns: the R:R ratio below is your asymmetry edge.
Track your £20,000 annual ISA (Individual Savings Account) allowance across all four ISA types — with UK usage benchmarks from HMRC.
HMRC distribution of annual ISA contributions across 12 million active ISA accounts (2023/24):
| Contribution range | % of ISA holders | Annual amount |
|---|---|---|
| Bottom 50% | ~6.0m | Under £2,500 |
| Median saver | ~50th pct | £3,800 |
| Top 25% | ~3.0m | £8,000+ |
| Max out full £20,000 | ~12% | £20,000 |
If your contribution was invested at 7% annual growth outside an ISA, a higher-rate taxpayer would pay 24% CGT on gains above the £3,000 annual allowance plus 33.75% on any dividends above £500. Inside an ISA, all gains and income are tax-free forever.
Track your child's £9,000 Junior ISA (JISA) allowance and project what their pot could be worth at 18 — tax-free for life, locked until the child turns 18.
Out of roughly 13 million eligible children in the UK, less than 10% are actively saving in a JISA each year. The average annual contribution is around £1,250 — well below the £9,000 cap. Starting early and consistently is what compounds matter most for; the gap between starting at birth versus age 10 can be £40,000+ at age 18 with modest contributions.
| When you start | £100/mo at 6% | £200/mo at 6% |
|---|---|---|
| Age 0 (newborn) | £38,700 | £77,400 |
| Age 5 | £23,000 | £46,000 |
| Age 10 | £11,800 | £23,600 |
| Age 15 | £4,100 | £8,200 |
Investment income and gains inside a Junior ISA are completely tax-free, forever. The same contributions in a regular taxable account would face CGT on gains above £3,000 and dividend tax on income above £500 each year — and any income above £100/year from a parent's gift to the child gets taxed as the parent's income (the "settlements rule"). JISA neatly sidesteps both.
Project your pension pot and monthly income at retirement — with UK benchmarks for pot size, contribution levels, and State Pension.
Median private pension pot by age group across UK households (ONS Wealth & Assets Survey 2022, most recent available):
| Age group | Median pot | Top 25% pot |
|---|---|---|
| 25–34 | £8,000 | £32,000 |
| 35–44 | £29,000 | £106,000 |
| 45–54 | £71,000 | £230,000 |
| 55–64 (pre-retirement) | £107,000 | £380,000 |
Your projection excludes State Pension. Most UK savers qualify for the full New State Pension, which adds £958/month on top of your private pot from age 66. Your projected monthly income below is the private pension only.
The UK auto-enrolment minimum is 8% of qualifying earnings (5% employee + 3% employer). On the UK median salary of £34,963, that's about £197/month combined. Most financial planners suggest 12–15% to maintain your standard of living in retirement.
Estimate what you'd actually owe HMRC after the £3,000 allowance — using the current 2024/25 rates that took effect 30 October 2024.
The annual tax-free allowance has been cut twice: from £12,300 (2022/23) to £6,000 (2023/24) to £3,000 (2024/25). Rates on shares also stepped up from 10%/20% to 18%/24% on 30 October 2024.
| Tax year | CGT allowance | Share rates (basic / higher) |
|---|---|---|
| 2022/23 | £12,300 | 10% / 20% |
| 2023/24 | £6,000 | 10% / 20% |
| 2024/25 (current) | £3,000 | 18% / 24% |
CGT doesn't apply inside ISAs or SIPPs. "Bed & ISA" is the common technique: sell taxable holdings, repurchase inside your £20,000 annual ISA allowance. Future gains on those shares are then tax-free.
Your FIRE number (Financial Independence, Retire Early) — the pot size you need to live off investment returns, plus how long it'll take to get there. Benchmarked against UK retirement norms.
The PLSA publishes benchmark annual incomes for three retirement standards (single person, excluding housing).
| Standard | Annual need | Pot required (4%) | |
|---|---|---|---|
| Minimum | £14,400 | £360,000 | |
| Moderate | £31,300 | £782,500 | |
| Comfortable | £43,100 | £1,077,500 |
Most UK savers will qualify for a full New State Pension (currently £221.20/week). At a 4% withdrawal rate, that's equivalent to ~£287,550 in pot value — reducing your needed pot by the same amount if you retire at 66 or later.
The average UK adult contributes about £280/month to an ISA — roughly £3,400/year. Auto-enrolment pensions add another 8% of qualifying earnings on top (5% employee, 3% employer minimum).
Work out current yield, yield-on-cost, and income — benchmarked against the UK market's actual payouts.
UK dividend yields across major indices — use these as a sanity check on what's sustainable. Yields above 7% often signal a falling share price (a "dividend trap") rather than a strong payout.
| Index | Trailing 12-mo yield | Character |
|---|---|---|
| FTSE 100 | 3.8% | Blue-chip income |
| FTSE 250 | 3.2% | Mid-cap UK |
| FTSE All-Share | 3.7% | Broad UK market |
| S&P 500 (reference) | 1.4% | Growth-tilted |
The UK dividend allowance is £500 (2024/25 tax year). Above that, rates depend on your income tax band: 8.75% (basic), 33.75% (higher), 39.35% (additional). Dividends inside a Stocks & Shares ISA are tax-free entirely.
Estimate what a stock is really worth using its P/E ratio (share price ÷ annual earnings per share) and a target multiple — sanity-checked against UK market P/E ranges.
UK equities typically trade at lower multiples than US — the "UK discount" has averaged 4-6 P/E points for a decade. Anchor your fair value to the sector, not to S&P 500 levels.
| Index / Sector | Trailing P/E | Character |
|---|---|---|
| FTSE 100 | ~13× | Defensive value |
| FTSE 250 | ~14× | UK mid-cap |
| AIM UK 50 | ~18× | Growth-tilted |
| S&P 500 (reference) | ~22× | Tech-heavy premium |
Benjamin Graham's classic margin-of-safety rule: buy at 33%+ below your fair value estimate. Below 20%, you're paying close to fair value with little cushion if estimates are wrong.
See how DCA (Dollar-Cost Averaging — also called pound-cost averaging: drip-feeding a fixed amount each month) smooths out price volatility and builds a position over time, rain, shine or crash.
The core trade-off: DCA reduces regret-risk during drawdowns, but historically lump-sum investing beats DCA in most rolling UK market periods.
| Rolling 10-yr period | Lump sum wins | DCA wins |
|---|---|---|
| UK FTSE All-Share (1990–2024) | ~68% | ~32% |
| Global equities (GBP-hedged) | ~71% | ~29% |
| 60/40 balanced portfolio | ~66% | ~34% |
UK equity annual volatility sits around 15% (σ). DCA's real edge is behavioural — it removes the "when to buy" decision and forces consistent contributions through drawdowns, which most UK retail investors otherwise pause.
Work out the tax HMRC takes on UK and Irish share purchases — and which markets are exempt.
SDRT is charged at 0.5% on most UK main market share purchases with no minimum threshold. But several markets and share types are entirely exempt — knowing which ones can save hundreds per year for frequent traders.
| Market / Asset | SDRT rate | Why |
|---|---|---|
| LSE Main Market | 0.5% | Standard UK equities |
| AIM-listed shares | 0% | Exempt since 2014 |
| ETFs (all) | 0% | Fund units, not shares |
| Gilts / Corporate bonds | 0% | Not equity instruments |
| Irish-registered stocks | 1.0% | Irish stamp duty (double UK rate) |
If you make 10 trades of this size per year on LSE Main Market, here's what SDRT takes from you versus the same volume in AIM-listed shares or ETFs.
Estimate HMRC's cut of your dividend income after the £500 allowance — at current 2024/25 rates.
Chancellors Hunt (2023) and Reeves (2024) both cut the dividend allowance as an under-the-radar tax rise. Rates on dividends above the allowance have stayed the same — 8.75% / 33.75% / 39.35% across basic, higher, and additional bands.
| Tax year | Dividend allowance | Tax on this dividend |
|---|---|---|
| 2022/23 | £2,000 | — |
| 2023/24 | £1,000 | — |
| 2024/25 (current) | £500 | — |
Dividends from shares held in a Stocks & Shares ISA are fully tax-free — no allowance, no rate, no reporting. The £20,000 annual ISA allowance covers most retail dividend portfolios entirely.
Estimate your take-home pay after Income Tax and NI (National Insurance), with your position in the UK earnings distribution — and a clear breakdown of which tax band your money goes into.
Gross annual earnings for UK full-time employees (ONS Annual Survey of Hours and Earnings, April 2024):
| Percentile | Gross salary | Monthly take-home |
|---|---|---|
| Bottom 25% | < £26,800 | ~£1,855 |
| Median (50%) | £34,963 | ~£2,356 |
| Top 25% | £45,000+ | ~£2,899 |
| Top 10% | £60,000+ | ~£3,724 |
| Top 1% | £183,000+ | ~£9,347 |
UK income tax is marginal: each slice of your salary is taxed at a different rate. The "effective rate" is your overall tax, which is always lower than your top marginal rate (because the first £12,570 is tax-free).
| Band | Range | Rate | Your tax in this band |
|---|---|---|---|
| Personal allowance | £0 – £12,570 | 0% | £0 |
| Basic rate | £12,571 – £50,270 | 20% | £0 |
| Higher rate | £50,271 – £125,140 | 40% | £0 |
| Additional rate | £125,141+ | 45% | £0 |
Enter your holdings to visualise your portfolio split — and sanity-check it against UK investor norms and risk-aware model portfolios.
The classic 60/40 (equities/bonds) has been the UK default for decades. Modern model portfolios tilt more aggressive in your 30s and more cautious as retirement nears. Use these as benchmarks, not prescriptions.
| UK model portfolio | Equity / Bond / Cash | For |
|---|---|---|
| Vanguard LifeStrategy 80 | 80 / 20 / 0 | Long horizon, risk-tolerant |
| Vanguard LifeStrategy 60 | 60 / 40 / 0 | Balanced default |
| Vanguard LifeStrategy 40 | 40 / 60 / 0 | Cautious / near-retirement |
| Near-retirement cautious | 30 / 50 / 20 | Capital preservation |
The UK makes up only ~4% of global market cap, but UK retail investors typically allocate 15-30% to UK equities (home bias). Some home bias is rational for currency-matched liabilities (mortgage, living costs) — but a 50% UK allocation is concentration risk masquerading as familiarity.
Losses are asymmetric — a −50% drop needs a +100% gain to break even. See exactly how long recovery takes at typical UK market returns.
UK market drawdowns since 2000 — note how the time to recover is often longer than the depth of the drop suggests, because early-recovery gains rebuild from a smaller base.
| Event | FTSE 100 max drawdown | Recovery time |
|---|---|---|
| Dot-com crash (2000–03) | −49% | ~6 years |
| Global Financial Crisis (2007–09) | −44% | ~4.5 years |
| Covid crash (Feb–Mar 2020) | −33% | ~16 months |
| 2022 inflation shock | −10% | ~8 months |
DALBAR and Morningstar research consistently shows retail investors underperform the market by 2–4% per year, mostly by selling near the bottom of drawdowns and buying back after recovery is well underway.
The eternal UK dilemma — pay down the mortgage or put that surplus into the market? See which wins at current rates.
Rule of thumb: if you can reliably earn more than your mortgage rate (net of tax), invest. Below it, overpay. But consider the certainty premium — saving 4.5% in guaranteed mortgage interest beats a 7% expected but uncertain investment return on a risk-adjusted basis for many people.
| Scenario | Mortgage rate | Usually wins |
|---|---|---|
| 2015–2021 legacy fix | ~1.5–2.5% | Invest (wide spread) |
| 2024 new mortgage | ~4.5–5.5% | Toss-up / ISA-dependent |
| Distressed refix | 6.0%+ | Overpay (certainty wins) |
The £20,000/yr ISA allowance makes investment returns fully tax-free. Outside an ISA, a higher-rate taxpayer loses 33.75% of dividends and 24% of capital gains above £3,000 — enough to wipe out the spread entirely in some cases.
Track unrealised P&L (profit & loss — the gain or loss before you actually sell) and break-even point after round-trip fees, so you can see what a position is really worth after costs.
HMRC treats crypto as an asset for CGT purposes — same rules as shares. The first £3,000 of gains per tax year is tax-free. Above that: 18% (basic rate) or 24% (higher rate) on the excess. Losses can be carried forward indefinitely.
| Your tax band | CGT rate (2024/25) | Tax on this gain |
|---|---|---|
| Basic rate (£12,570–£50,270) | 18% | — |
| Higher rate (£50,270+) | 24% | — |
| Inside an ISA / SIPP | 0% | Not possible — crypto can't go in ISAs |
UK crypto exchanges charge 0.1–1.5% per trade. A 0.5% round-trip fee on a position is roughly equivalent to an 0.25% performance drag per year if held for 2 years. Active trading compounds this quickly — a 1% round-trip done 10 times a year is a 10% annual return drag.
