Tools & calculators
Understand it, then calculate it
24 tools. Each one explains its formula, shows a worked example, then lets you change every number. Private by design: nothing leaves your browser.
8 tools
Borrow
The true price of credit, and how to compare it.
Chapters 3 and 11
Rate translator
Convert a quoted rate into what it really costs per year.
Open →Chapter 11 · The True Cost of Borrowing
True cost of a loan
Payment, total cost and effective rate, and what a flat rate really means.
Open →Chapters 11 and 15
Compare two loan offers
Two offers side by side: which one is really cheaper?
Open →Chapter 12 · Credit Cards, Overdrafts and Revolving Debt
The minimum-payment trap
How long a card balance survives on minimum payments, and what it costs.
Open →Chapter 14 · Making Debt Decisions
Debt payoff planner
Avalanche, snowball or minimums: which order clears your debts?
Open →Chapters 10 and 14
Borrowing capacity & debt-to-income
How lenders see your income, and how much borrowing is wise.
Open →Chapter 13 · Mortgages and the Rent-or-Buy Question
Mortgage explorer
Payment, interest over the term, the effect of overpaying and a rate shock.
Open →Chapter 13 · Mortgages and the Rent-or-Buy Question
Rent or buy?
Compare the money position after N years of renting versus buying.
Open →
5 tools
Save & grow
Time, buffers and goals.
Chapter 3 · The Price of Time
Compounding & time
See what a lump sum and a monthly habit become, before and after inflation.
Open →Chapter 2 · The Quiet Tax
The quiet tax
What your money buys in the future when prices keep rising.
Open →Chapter 7 · Resilience
Buffer calculator
How many months of essentials to hold, and how far you are from it.
Open →Chapters 8 and 25
Goal calculator
How much to put aside each month to reach a target by a date.
Open →Chapter 7 · Resilience
Irregular income smoother
Turn lumpy income into a steady “salary” with a buffer in the middle.
Open →
1 tools
Protect
Insure what would ruin you.
3 tools
Invest
Costs, losses and keeping a portfolio on track.
Chapter 21 · The Cost of Investing
The cost of investing
The same money in two products with different annual fees.
Open →Chapter 20 · Risk and Return in Practice
Losses and recovery
Why a 50% fall needs a 100% gain, and how long recovery can take.
Open →Chapter 22 · Building and Keeping a Portfolio
Rebalancing
See how far a portfolio has drifted from its plan, and what to move.
Open →
7 tools
Plan ahead
Margin, retirement, earning power and independence.
Chapters 1 and 6
Margin & net worth
What is left each month, and what you own minus what you owe.
Open →Chapter 4 · Every Choice Has a Price
True cost of owning
What a car, a gadget or a subscription really costs, including what the money could have done.
Open →Chapter 24 · Retirement Across Systems
Withdrawal rates
What a pot might pay in its first year, and whether it could last.
Open →Chapter 24 · Retirement Across Systems
Retirement readiness
Will your savings, plus other income, cover the life you want?
Open →Chapter 23 · Your Largest Asset: Earning Power
Return on skills
Is a course, qualification or career move worth what it costs?
Open →Chapter 25 · Wealth, Time and Your Financial Strategy
Savings rate & independence
How the share of income you keep changes how long wealth takes.
Open →Chapter 24 · Retirement Across Systems
Pension sources across systems
Add up pensions from several countries and see what is available when.
Open →