UK money guides
Written explainers for the questions behind the calculators. Figures match the tools on this site and link to official sources. Guidance only, not advice.
Pay and tax: how take-home pay is built, how National Insurance differs from Income Tax, how student loan deductions are taken, how pension salary sacrifice compares with relief at source, and how statutory redundancy pay is built from age, service and a capped week’s pay.
Homes and estates: how stamp duty is sliced, how a repayment mortgage actually works, how Inheritance Tax is sliced from the nil-rate band, the extra home allowance and transferred unused bands, how Capital Gains Tax is sliced from the gain — not the sale price — at 18% or 24% after the £3,000 allowance, how Council Tax is billed from a historic valuation band times your council’s Band D charge, and how car tax (VED) changes with the first-registration date.
Everyday money maths: how a credit-card balance is cleared from APR, a fixed monthly payment and monthly compound interest; how a fuel bill is built from miles, UK imperial MPG and the pump price; how UK VAT is added and stripped — divide by 1.20, do not subtract 20%; how inflation turns £1,000 of idle cash into £744.09 of today’s goods at 3% over 10 years; and how compound interest turns £5,000 plus £200 a month at 5% into £39,291.50.
Guide
How UK take-home pay is calculated (2026/27)
A plain-English walkthrough of Income Tax, National Insurance and why a £30,000 salary is not £30,000 in the bank.
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Guide
How stamp duty works when you buy a home in the UK
SDLT, LBTT and LTT explained: why tax is charged in slices, and what first-time buyers and additional properties usually change.
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Guide
How UK mortgage payments are calculated
The repayment formula in plain English, why term and rate move the monthly figure, and what a calculator leaves out.
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Guide
How UK student loan repayments work (2026/27)
Why a student loan is not a personal-loan instalment: plan types, 2026/27 thresholds, two jobs, postgraduate stacking and worked salary examples.
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Guide
How UK National Insurance is calculated (2026/27)
Employee, employer and self-employed NI as separate bills — why it is not Income Tax, and what a £30k or £60k salary actually costs.
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Guide
How UK car tax (VED) works in 2026/27
Why two cars with the same CO₂ can have different bills: first-registration eras, first-year rates, the £200 standard rate and the expensive-car supplement.
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Guide
How UK pension salary sacrifice compares to relief at source
Why the extra take-home from salary sacrifice is usually National Insurance, not extra tax relief — with £45k, £60k and £100k worked examples.
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Guide
How UK statutory redundancy pay is calculated (2026)
Why statutory redundancy is not “a month per year of service”: two-year eligibility, the GOV.UK age-band walk-back, April 2026 caps, and worked £7,200 / £3,755 examples.
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Guide
How UK Inheritance Tax is calculated (2026/27)
Why IHT is a slice of the estate, not a tax on heirs: the £325,000 band, the extra home allowance, transferred unused bands, and a worked £500k → £70,000 example.
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Guide
How UK Council Tax bands and bills are calculated
Why the bill is a fraction of your council’s Band D charge, not a tax on today’s sale price — with Band C from £2,100 Band D ≈ £1,867, and Scotland’s 2017 Band E–H multipliers.
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Guide
How UK credit card interest and payoff time are calculated
Why a £2,500 balance at 22% APR paying £100 a month takes about 34 months and £875 in interest — and why the statement minimum can stretch the same debt into years.
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Guide
How UK fuel cost is calculated from miles, MPG and the pump price
Why 100 miles at 45 mpg and 145p a litre costs about £14.65 — and why a 30-mile commute at 40 mpg is closer to £50 a working week.
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Guide
How UK VAT is calculated: add, remove and the 1.20 trap
Why £100 net at 20% is £120 gross — and why stripping VAT means dividing by 1.20, not taking 20% off the receipt.
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Guide
How UK inflation erodes cash — and what a real return means
Why £1,000 left idle at 3% inflation for 10 years buys only £744.09 of today’s goods — and why a 5% return is 1.94% in real terms, not 2%.
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Guide
How compound interest is calculated on a UK savings pot
Why £5,000 plus £200 a month at 5% for 10 years is £39,291.50 — not 10 × 5% of what you put in — and how monthly compounding changes the total.
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Guide
How UK Capital Gains Tax is calculated (2026/27)
Why you pay CGT on the gain, not the sale price: the £3,000 allowance, 18% or 24% from unused basic-rate band, and GOV.UK’s £12,600 → £1,728 example.
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