💰 Finance Tools

Estimate your monthly mortgage payment from the loan amount, rate and term, and see how much of each early payment goes to interest rather than principal.

Calculate the monthly payment, total interest and payoff cost for any fixed-rate loan, with the difference between rate and APR made explicit.

See how savings or investments grow with compound interest and regular contributions, with the effect of compounding frequency and inflation made explicit.

Estimate your paycheck after federal income tax and FICA using current US brackets, with a clear account of what the estimate cannot include.

Compare the snowball and avalanche methods to see how fast you can clear your debts, and what the difference in total interest actually amounts to.

Find how much to save each month to reach a goal by a target date, working in both directions — and what to do when the number is unaffordable.

Split a bill evenly or by shares, with tip and tax handled correctly, and see exactly what each person owes.

Work out markup, profit margin and return on investment from cost and price — including why a 50 per cent markup is not a 50 per cent margin.

Work out percentages, percentage change and what percent of one number another is — including why a rise and fall of the same percentage never cancel.

Calculate the tip and split a bill between any number of people, with the conventions that differ enough between countries to cause offence.

Project retirement savings from your current balance, contributions and expected return — with the assumptions that make any such projection soft.

Calculate the sale price and what you save from an original price and a percentage off — including how stacked discounts actually combine.

Add sales tax to a price or work backwards to find the pre-tax amount, with the difference between sales tax and value-added tax explained.

Compare two US cities and see the salary you would need to keep the same standard of living after a move — with the caveats on such indices.

A full loan payoff table with yearly or per-payment views, plus extra-payment and biweekly comparisons showing exactly what each strategy saves.

What overtime hours, holiday days and a raise are actually worth — in money per year, month and hour, so you can compare them properly.

Set a months-of-expenses target, see your funding progress and get a date you will reach it, with guidance on how many months actually suits your situation.

See how long a retirement pot lasts at a given withdrawal rate, or what it can sustainably pay out, including why the order of returns matters so much.

See what a daily coffee, subscription or any recurring habit costs over years, and what the same money invested might have become instead.

Work out how much house you can afford from your income, debts and deposit using the 28/36 rule, with what lenders count and what they leave out.

Convert pay between hourly, weekly, monthly and yearly — and see what an hourly wage actually is as an annual salary.

Overall and per-card utilisation, what each target costs to reach, and why closing a card you have paid off makes the number worse.

Front-end and back-end ratios against the 28/36 rule, showing which of the two limits actually binds — because it is not always the same one.

Compare transferring against staying put, including what is left when the promotion ends — and why the transfer fee is rarely what decides it.

Compare any number of pack sizes per unit, and see how much of the big one you can throw away before it stops being the cheaper buy.

Compare two purchases by what each costs per use, including upkeep — and see how many uses the dearer one needs to justify itself.

Work out when an annual fee pays for itself, counting only the visits you would have made anyway — which changes the answer completely.

Compare a repair bill against a replacement on cost per year, and see how often the familiar 50% rule gets it wrong.

Compare two options on price plus running costs, and find the exact year the cheaper purchase stops being the cheaper choice.

Work out how long you need a tool or machine before buying beats renting, counting what you get back when you sell it.

Compare any number of plans on premium, deductible, coinsurance and out-of-pocket maximum, and find the level of care where they swap places.

Work out how often you would have to claim for a lower deductible to be worth its extra premium, on car or home cover.

Find the most your comprehensive and collision cover could ever pay, and how many years of premium equal it.

Work out cover using the DIME method, and see how far the ten-times-income rule of thumb misses for your household.

Find the annual return the premium difference would need to match a whole-life cash value — which is sometimes negative.

See what a disability policy actually replaces after the monthly cap and tax, which depends on who paid the premium.

See what 25/50/25 actually pays on a real accident, and how much is left for you — the three numbers do not add together.

Work out the gap above your existing liability limits, and why umbrella cover gets cheaper per million as you buy more.

Check your dwelling cover against the coinsurance clause, which penalises every partial claim if you insure below the required share.

Work out net operating income and cap rate for a rental, and see why the figure is identical however you finance the purchase.

Cash flow against cash invested for a rental, including the loan constant — the hurdle a cap rate has to beat, which is not the interest rate.

Run the 1%, 2% and 50% rules against a property, and see where each screen is blind — two buildings can pass identically and cash-flow oppositely.