US edition
Free Financial Calculators for US Readers
Every tool here runs on currency-agnostic maths: compounding, withdrawal rates, payoff schedules. No UK tax rules involved.
Switch the edition toggle in the header to US and the universal calculators below display in dollars - the 7 US-native tools are always in dollars, no toggle needed. The maths never needed converting - a 7% return compounds the same way everywhere - the symbols just follow you now. Looking for the UK versions? All tools live here.
Save and Invest
Compound Interest Calculator
See how your investments grow over time with regular contributions. Supports daily, monthly, and yearly compounding with CSV export.
£500/mo for 30 years at 7% -> ~£589k
Use calculatorDrip Feed vs Lump Sum
Compare investing a lump sum all at once against drip feeding it in over several months. See which strategy comes out ahead.
Vanguard data: lump sum wins ~2/3 of the time
Use calculatorTime in the Market
Compare perfect market timing, worst timing, and consistent investing using real S&P 500 data. Spoiler: consistency wins.
Missing the 10 best days roughly halves returns
Use calculatorCoast FIRE Calculator
Find out if you can stop saving and let compound growth carry you to financial independence. Calculate your Coast FIRE number.
£100k invested at 30 can coast-FIRE by 60
Use calculatorBarista FIRE Calculator
See how much smaller your portfolio can be when a part-time job covers some of your expenses, and how many years of full-time work that saves. Dollars, US framing.
$20k of part-time income cuts a $1.5m FIRE number to $1m
Find my barista numberPlan and Track
Net Worth Tracker
Track every asset and liability over time. Independent category updates, interest rate tracking, and net worth charts.
Log assets and debts month by month
Open trackerUS Net Worth Percentile
See what percentile your net worth puts you in for your age, using the Federal Reserve's 2022 Survey of Consumer Finances.
Your percentile on the US wealth distribution
Find your percentileEmergency Fund Calculator
Work out how much you need in your emergency fund and how long it will take to build it. Includes Personal Savings Allowance check.
£2k/mo expenses x 6 = £12k target
Use calculatorTax Optimisation
Borrow and Buy
Mortgage Calculator
See how regular overpayments can cut years off your mortgage and save thousands in interest.
£300k mortgage, 4.5%, 25 years -> £1,668/mo
Use calculatorRent vs Buy Calculator
Compare net worth after renting or buying a US home: 30-year mortgage, property tax, PMI and selling costs against the invested down payment, with the break-even year charted.
$400k home vs $2k rent, both net worths charted to break-even
Run my numbersDebt Payoff Calculator
Compare snowball vs avalanche strategies for paying off multiple debts. See which saves more interest and time.
Avalanche vs snowball, side by side
Use calculatorLoan Calculator
Calculate monthly repayments, compare loan offers side by side, and see how much you can afford to borrow.
£20k at 8% over 5 years -> £406/mo, £4.4k interest
Use calculatorRetire
FI Number Calculator
Find the exact portfolio size you need to be financially independent, and how long it will take to get there. Includes reverse mode to plan by retirement age.
£35k annual spend × 25 = £875k FI number
Use calculatorRetirement Monte Carlo Simulator
Stress-test your retirement pot against hundreds of simulated market histories. See your success rate, percentile bands, and when the unluckiest paths run dry.
1,000 simulated retirements -> your success rate
Run my simulation401(k) Match Calculator
Calculate your employer 401(k) match in dollars: the match per year, what you leave on the table below the cap, and what the match compounds to by retirement.
Your match per year, and what it compounds to
Use calculatorSocial Security Break-Even Calculator
Compare claiming Social Security at 62, 67 or 70 and find the break-even age where the bigger, later check overtakes the earlier one in cumulative dollars.
Claim at 62 or wait for 124% at 70? Find the crossover age
Find my break-even ageUnderstand the System
Why only 19 of our 54 tools? The rest calculate UK-specific things - British income tax, stamp duty, ISA and pension rules - and a wrong-country tax calculator is worse than none. These are the ones whose maths crosses the Atlantic intact. More US-specific tools are on the roadmap.
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