Practical guides for USA, UK, and South Africa — retirement, tax, budgeting, debt, and more.
The blog exists to explain the math behind the calculators. Each guide takes a single personal-finance question — "how much do I actually need to retire", "should I pay off my loan early", "what does my payslip really look like after PAYE" — and walks through the formula, the assumptions, and a worked example using figures that match the current published tax tables for the USA, the UK, and South Africa.
Every figure links back to a primary source: HMRC for UK income tax and NI, SARS for South African PAYE and rebates, the IRS for US federal brackets and retirement contribution limits, the Bank of England and the Federal Reserve for interest-rate context, the ONS and Statistics South Africa for wage and price data. If a number doesn't have a regulator's name behind it, we don't publish it.
Blog posts vs calculators — when to use each. The calculators do the math for your specific inputs — your salary, your loan amount, your retirement target. They run in your browser and give you a number in seconds. The blog posts explain why the math works the way it does, where the formula comes from, and what the answer means once you have it. If you want a number, use a calculator. If you want to understand the number, read the matching guide. Every blog post on the site links back to the relevant calculator, and most calculators link forward to the explanatory guide.
How much you need, when you can stop, and what the wrapper around the money should look like. Articles in this cluster sit on top of the standard retirement math — the 4% rule, the 25× rule, the SWR research — and translate it into the wrappers each region actually has: 401(k) and Roth IRA in the US, SIPP and ISA in the UK, RA and Two-Pot in South Africa. The numbers in the worked examples come from the IRS contribution limits, the HMRC pension allowance, and the SARS retirement-fund deduction cap for the current year.
Are you behind on retirement savings at 35? See benchmarks, the catch-up formula, and a step-by-step plan.
Read article →Compound interest is the most powerful force in personal finance. This guide explains exactly how it works.
Read article →Use this guide to calculate your real take-home pay after income tax, National Insurance, and other deductions.
Read article →Three months or six? Here is exactly how to calculate the right emergency fund for your situation.
Read article →Paying off a loan early saves interest — but not always as much as you think. Here is the full calculation.
Read article →The rent vs buy decision is one of the biggest in personal finance. Here is how to calculate the break-even point.
Read article →The 28/36 rule, UK income multiples, and SA bond affordability — all in one guide.
Read article →Retiring at 55 requires a bigger nest egg and a longer withdrawal period. Here is the maths.
Read article →A complete guide to retirement savings vehicles in South Africa — RA, pension fund, and the Two-Pot System.
Read article →Pre-tax 401(k) contributions reduce your taxable income. Here is exactly how they change your payslip.
Read article →The simplest budgeting framework that actually works. Split your take-home pay into needs, wants, and savings.
Read article →How does your net worth compare to others your age? Benchmarks and strategies for every decade.
Read article →Inflation silently shrinks your savings every year. See how to protect your money.
Read article →Two proven methods to pay off multiple debts. Compare total interest paid with real examples.
Read article →A practical step-by-step plan to pay off credit card debt and stop the interest spiral.
Read article →Is your net worth on track at 40? Benchmarks, rules of thumb, and practical strategies.
Read article →Your 30s are the most important decade for building wealth. These 7 moves have the highest ROI.
Read article →How many qualifying years you need, how much you get, and how to maximise your State Pension.
Read article →A step-by-step guide to building a monthly budget from scratch. Works for any income.
Read article →Learn how to use an investment growth calculator accurately — return rates, inflation, and realistic planning.
Read article →The answer depends on your age, income, and goals. Savings rates and targets for every stage.
Read article →Complete SARS tax guide — brackets, rebates, medical credits, and how to calculate your tax bill.
Read article →UK NI rates, thresholds, employer contributions, and how NI builds your State Pension entitlement.
Read article →The cornerstone of retirement planning — scrutinised, adjusted, and applied for modern portfolios.
Read article →Deposit requirements, LISA, FLISP, and a structured saving plan for first-time buyers.
Read article →Exact PAYE calculation on R500,000 salary — brackets, rebates, effective rate, and monthly take-home.
Read article →The UK Personal Allowance is £12,570 for 2024/25. How the taper above £100,000 works and how to protect it.
Read article →PAYE is income tax deducted from your salary monthly. How it is calculated, what reduces it, and what to do if it is wrong.
Read article →SDLT rates for 2024, first-time buyer relief, second home surcharge, Scotland LBTT, and Wales LTT explained.
Read article →A 401(k) employer match is free money. How matching formulas work, vesting schedules, and the contribution order of operations.
Read article →The articles above are grouped by cluster in the tags on each card — tap the tag to see related guides. Here's what each cluster covers and why we write about it.
The cluster that gets the most reader correction emails — and rightly so, because tax tables change every year and the difference between the right and wrong number is real money. Articles cover UK income tax, the National Insurance bands, the personal-allowance taper above £100,000, US federal brackets, FICA, SA PAYE, the primary/secondary/tertiary rebates, medical credits, and the practical difference between what you earn on paper and what hits your bank account. Every figure is from HMRC, the IRS, or SARS for the current tax year, and every article carries a "last reviewed" date so you can tell at a glance whether the post-Budget update has landed.
How much you can borrow, how much you'll actually pay, and whether to fix or float. The math is the standard amortising annuity formula with monthly compounding — the same formula UK lenders publish — but the wrappers differ: 30-year fixed in the US, 25-year capital-and-interest in the UK with a two-to-five-year fix on top, 20-year variable-rate bond in South Africa. Articles also cover the costs that sit outside the headline rate: UK stamp duty land tax (with first-time-buyer relief and the second-home surcharge), Scotland's LBTT, Wales's LTT, SA transfer duty and bond registration costs, US closing costs and points.
The avalanche-vs-snowball debate, what compounding does to a balance left to its own devices, and how to model "pay extra now" against "invest the difference". Articles in this cluster lean heavily on worked examples: a £5,000 credit-card balance at 24.9% APR, a $30,000 student loan at 6.8%, an SA personal loan at prime + 10. The math gets compared like-for-like — same balance, same minimum payment, same extra contribution — so the reader can see exactly what the choice costs in total interest and months to debt-free.
Where you should be by 30, 40, 50, and what the median household actually holds at each stage. Articles in this cluster pull from the ONS Wealth and Assets Survey for the UK, the Federal Reserve's Survey of Consumer Finances for the US, and Statistics South Africa's living-conditions and income-and-expenditure surveys for South Africa. Benchmarks are a starting point, not a destination — the guides explain how to read the headline number alongside the distribution it came from.
The 50/30/20 rule, zero-based budgeting, envelope systems, and how to build a monthly plan that survives the second-month motivation drop. The cluster avoids prescriptive "do this exact thing" advice and instead walks through the frameworks — what each one is solving for, where each one breaks, and how to pick the one that fits your income shape. Worked examples use take-home pay figures that match the current PAYE/NI/FICA tables so the numbers in the article are the numbers you'd actually have to budget with.