Free tools & calculators
The same clear-headed math Stoia is built on: free, instant, and private. Everything runs in your browser: we never see a number you type.
Budgeting & saving
50/30/20 Budget Calculator
“How should I split my paycheck each month?”
Free 50/30/20 budget calculator: enter your monthly after-tax income and get exact dollar targets for needs, wants, and savings, with adjustable percentages.
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Emergency Fund Calculator
“How much cash cushion do I need?”
Work out how much emergency fund you actually need based on your essential monthly expenses, how many months of cover you want, and how long it will take to save it.
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Savings Goal Calculator
“How much do I need to save each month to hit my goal?”
Plan any savings goal: find the monthly amount needed to hit a target by a deadline, or how long your current saving rate will take, including interest earned along the way.
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Rent Split Calculator
“What's a fair share of the rent for each of us?”
Split rent fairly with roommates or a partner: divide evenly, proportionally by income, or by room size. See exactly what each person owes. Free, no sign-up.
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HYSA Interest Calculator
“How much more would a high-yield account earn me?”
See what a high-yield savings account would earn you versus a traditional savings rate: enter your deposit, monthly contribution, and APYs to compare balances over time.
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Subscription Cost Calculator
“What do my subscriptions really cost me?”
Total what your subscriptions really cost per month and per year, and see what that money could become if invested instead. Free, private, runs entirely in your browser.
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Savings Rate Calculator
“What share of my income am I actually keeping?”
Calculate your true savings rate from take-home pay and retirement contributions, see how it compares to common benchmarks, and what it means for your years to financial independence.
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CD Calculator
“What will this CD actually earn me?”
Calculate what a certificate of deposit earns by maturity from your deposit, APY, and term, and compare terms side by side. Free, private, runs in your browser.
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APY Calculator
“What does this rate really pay once compounding counts?”
Convert APR to APY and back for any compounding frequency, and see what the difference is worth in dollars on your balance. Free, no sign-up.
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Sinking Fund Calculator
“How much per month covers my irregular bills?”
Turn irregular bills into monthly line items: list upcoming expenses and their due dates and get the monthly slice for each, plus the total to set aside.
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Income-Based Expense Split Calculator
“What's a fair split of shared bills when we earn different amounts?”
Split shared expenses fairly when incomes differ: this free calculator shows each partner's proportional share vs a 50/50 split, by category. No sign-up.
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Simple Interest Calculator
“How much interest does a flat rate earn over time?”
Simple interest, solved: enter principal, rate, and years for interest earned and the final amount, with a year-by-year compound comparison. Free, no sign-up.
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Debt & credit
Debt Payoff Calculator
“When will I be debt-free, and which method is faster?”
Compare the debt snowball and debt avalanche methods side by side: months to debt-free, total interest paid, and your exact payoff order. Free, no sign-up.
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Debt-to-Income Calculator
“Is my debt load in the range lenders want to see?”
Calculate your debt-to-income ratio the way lenders do: front-end and back-end DTI from your monthly income and debt payments, with the ranges mortgage lenders look for.
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Loan Payoff Calculator
“What does paying a little extra actually save me?”
See what extra payments do to any loan: months cut from the payoff date and interest saved, from your current balance, rate, and payment. Free, no sign-up.
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Car Affordability Calculator
“How much car fits my budget without wrecking it?”
Work out how much car you can afford with the 20/4/10 rule: 20% down, a loan of 4 years or less, and total car costs under 10-15% of income. Free, no sign-up.
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Auto Loan Calculator
“What will this car payment really be?”
Calculate your monthly car payment and total interest from vehicle price, down payment, trade-in, rate, and term, and see how a shorter loan changes the math.
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Credit Card Payoff Calculator
“How long am I stuck with this balance, and what ends it?”
See how long your credit card balance takes to pay off at the minimum payment versus a fixed amount, and how much interest each path costs. Free, no sign-up.
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Student Loan Calculator
“When will my student loans actually be gone?”
Calculate your student loan payment, payoff date, and total interest, and see what extra monthly payments do to the timeline. Free, private, runs in your browser.
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Credit Utilization Calculator
“Is my card usage hurting my credit score?”
Calculate your credit utilization per card and overall, see where you sit against the 30% and 10% guidance, and how much to pay down to reach a target ratio.
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Personal Loan Calculator
“What will a personal loan cost per month and in total?”
Free personal loan calculator: see your monthly payment, total interest, and year-by-year balance for any amount, APR, and term. No sign-up, nothing stored.
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Debt Consolidation Calculator
“Would one consolidation loan beat my current debts?”
Compare up to three debts against one consolidation loan: monthly payment, total interest, and months to debt-free both ways. Free, private, no sign-up needed.
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Balance Transfer Calculator
“Does a 0% transfer beat paying my card where it is?”
See if a 0% balance transfer beats staying put: interest avoided during the promo, the fee, and what's left when the rate snaps back. Free, no sign-up required.
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Lease vs. Buy Car Calculator
“Is leasing or buying cheaper over the years I'll drive it?”
Compare leasing and buying the same car over the years you'll actually drive it: total lease cost vs. net cost of owning after resale. Free, no sign-up needed.
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Housing & real estate
Rent Affordability Calculator
“How much rent can I actually afford on my income?”
See how much rent you can afford with the 25%, 30%, and debt-aware 36% rules, and check your current rent-to-income ratio the way landlords do. Free, no sign-up.
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Mortgage Calculator
“What will this house actually cost me per month?”
Calculate your monthly mortgage payment from price, down payment, rate, and term, with the full principal vs. interest breakdown and total cost over the life of the loan.
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Home Affordability Calculator
“What price range should I actually shop in?”
Find your home-buying budget the way lenders do: the 28/36 rule turns your income, debts, and down payment into a comfortable price range and a maximum monthly payment.
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Amortization Calculator
“How does each payment split between principal and interest?”
Free amortization calculator: get your monthly payment, total interest, and a year-by-year schedule of how each payment splits into principal and interest.
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Mortgage Payoff Calculator
“How much sooner could extra payments end my mortgage?”
See what extra mortgage payments buy: years cut from your payoff date, interest saved, and your new debt-free timeline. Free, no sign-up, runs in your browser.
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Biweekly Mortgage Calculator
“What does paying half my mortgage every two weeks save?”
Compare biweekly vs. monthly mortgage payments: total interest on each plan, the years you save, and how the extra 13th payment works. Free, no sign-up.
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Mortgage Points Calculator
“Should I pay points for a lower mortgage rate?”
Find out if mortgage discount points pay off: monthly savings, the break-even month, and a clear verdict for how long you plan to stay. Free, no sign-up.
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Refinance Calculator
“Would refinancing my mortgage actually save money?”
Check whether refinancing saves money: old vs. new payment, break-even on closing costs, and the lifetime interest difference. Free, private, no sign-up.
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Rental Property Calculator
“Will this rental actually cash flow?”
Free rental property calculator: enter price, rent, and loan terms to see cash flow, NOI, cap rate, cash-on-cash return, and a 5-year outlook. No sign-up.
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Rent vs. Buy Calculator
“Is renting or buying cheaper for the years I'll stay?”
Compare renting and buying year by year: total rent versus the cost of owning net of equity built, with a clear verdict for your timeline. Free, no sign-up.
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HELOC Calculator
“How much could I borrow against my home?”
See how much you could borrow against your home: available equity, the credit line a combined LTV allows, and the interest-only payment. Free, no sign-up.
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Down Payment Calculator
“How much do I need down, and when will I have it?”
Turn a home price into a savings plan: the dollars needed at 3%, 5%, 10%, or 20% down, what's left to save, and the months your pace takes. Free, no sign-up.
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Closing Cost Calculator
“How much cash do I really need on closing day?”
Estimate buyer closing costs from your home price, see the cash needed at closing with your down payment, and a typical line-item breakdown. Free, no sign-up.
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PMI Calculator
“What does PMI cost me, and when does it go away?”
Estimate monthly and annual PMI from price, down payment, and PMI rate, plus the loan balance and the date where PMI can finally come off. Free, no sign-up.
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Property Tax Calculator
“What will property taxes add to my monthly payment?”
Estimate annual property tax from assessed value and your local effective rate, see the monthly escrow slice, and project five years ahead. Free, no sign-up.
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Taxes & paycheck
Hourly to Salary Calculator
“What does this pay actually work out to?”
Convert an hourly wage to annual, monthly, and weekly pay, or a salary to its true hourly rate, with adjustable hours per week and weeks per year.
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Freelance Rate Calculator
“What should I charge per hour to hit my income goal?”
Set a freelance rate that actually pays: target income, business overhead, taxes, and realistic billable hours turned into the hourly rate you need to charge.
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Paycheck Calculator
“How much of my paycheck actually lands in my account?”
Free paycheck calculator: estimate your 2026 take-home pay per check after federal, state, and FICA taxes in any state, plus 401(k) effects. No sign-up.
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Bonus Tax Calculator
“How much of my bonus will I actually see?”
Free bonus tax calculator: see the flat federal withholding, Social Security, Medicare, and state tax on a bonus, and what you actually keep. No sign-up.
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Overtime Pay Calculator
“What do my overtime hours add up to over a year?”
Free overtime pay calculator: turn time-and-a-half hours into weekly and annual pay and see what 5, 10, or 20 extra hours a week really add. No sign-up.
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Self-Employment Tax Calculator
“What do Social Security and Medicare cost me on my profit?”
Free self-employment tax calculator: see your Social Security and Medicare tax on freelance profit, plus the deductible half that trims income tax. No sign-up.
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Quarterly Tax Calculator
“How much should I set aside and send in each quarter?”
Free quarterly tax calculator: find your safe-harbor target and the four estimated payments that avoid underpayment penalties. No sign-up, runs in your browser.
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Capital Gains Tax Calculator
“What will I owe on the investments I sold this year?”
Free capital gains tax calculator: federal tax on long-term and short-term gains with NIIT included, from your income and filing status. No sign-up needed.
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Retirement & FIRE
FIRE Calculator
“What's my FIRE number, and when could I reach it?”
Find your FIRE number and the year you could reach financial independence: enter your spending, savings, and monthly investing to see when work becomes optional. Free, no sign-up.
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Coast FIRE Calculator
“When can I stop saving and let compounding finish the job?”
Find your Coast FIRE number: how much you need invested today so growth alone funds retirement, whether you've hit it, and the age you could stop contributing. Free, no sign-up.
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Retirement Calculator
“Am I on track for the retirement I want?”
Project your retirement balance from savings, contributions, and time, then compare the income it could sustain against the retirement you actually want.
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401(k) Calculator
“What will my 401(k) grow to, and am I capturing the match?”
Project your 401(k) balance from salary, contribution percentage, and employer match, and see exactly what leaving match money on the table costs by retirement.
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Roth vs. Traditional Calculator
“Should my retirement dollars be Roth or traditional?”
Compare Roth and traditional retirement contributions using your tax bracket now versus in retirement, and see the after-tax outcome of each path side by side.
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Retirement Withdrawal Calculator
“How long will my money actually last?”
See how long your savings last at a given monthly withdrawal, or the withdrawal your balance can sustain, with growth and inflation in the math. Free, no sign-up.
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Social Security Claiming Calculator
“When should I claim Social Security?”
Compare claiming Social Security at 62, full retirement age, and 70: monthly benefit at each age and the break-even ages where waiting starts to win.
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College Savings Calculator
“How much per month gets us ready for college bills?”
Work out the monthly amount that reaches your college savings target by enrollment, with growth included, from your child's age and what you've saved so far.
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Life Insurance Calculator
“How much life insurance does my family need?”
How much life insurance do you need? This free DIME calculator adds debts, income years, mortgage, and education, minus what you already have. No sign-up.
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HSA Calculator
“What could my HSA grow to by 65, and what does it save me now?”
Free HSA calculator: project your health savings account to age 65, split contributions from growth, and see the tax this year's contribution saves. No sign-up.
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Roth IRA Calculator
“What will my Roth IRA be worth, tax-free, at retirement?”
Free Roth IRA calculator: project your balance at retirement and see exactly how much of it is growth you never pay taxes on. Live chart, no sign-up.
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RMD Calculator
“How much must I withdraw from my retirement account this year?”
Free RMD calculator: enter your age and prior year-end balance to get this year and next decade of required minimum distributions. No sign-up needed.
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Annuity Payout Calculator
“How much monthly income would an annuity pay me?”
Estimate the monthly income a lump sum could buy, as a payout rate or a fixed period that spends it down. Free annuity payout calculator, no sign-up.
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Solo 401(k) Calculator
“How much can I put away for retirement as a freelancer?”
Free solo 401(k) calculator for freelancers: your max employee deferral plus employer share, compared with a SEP IRA on the same profit. No sign-up.
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Net worth & investing
Net Worth Calculator
“What am I worth once debts are subtracted?”
Calculate your net worth in under a minute: add up everything you own, subtract everything you owe, and see how you compare with U.S. medians by age. Free, no sign-up.
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Compound Interest Calculator
“What will my savings grow to over time?”
See how your money grows with compound interest. Enter a starting balance, monthly contribution, rate, and time horizon to project your future balance year by year.
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Inflation Calculator
“What will my money actually buy in 10 years?”
See what inflation does to your money: how much today's dollars will buy in the future, what today's prices become, and how fast purchasing power erodes at any rate.
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Investment Fee Calculator
“What is that expense ratio quietly costing me?”
See what fund fees really cost over decades: the same portfolio at different expense ratios, the dollars lost to fees, and the balance you keep at each level.
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Millionaire Calculator
“When do I cross the million mark at this pace?”
Find the year your net worth crosses $1 million from what you have, what you invest monthly, and your expected return, plus what moves the date most.
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Rule of 72 Calculator
“How fast does my money double at this rate?”
Estimate how long money takes to double at any return with the rule of 72, compare it to the exact math, and see doubling times across common rates.
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Investment Calculator
“What could my investments grow to over time?”
Free investment calculator: project your balance year by year from a starting amount, monthly contributions, and a chosen annual return. No sign-up needed.
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Dividend Calculator
“How much dividend income will my portfolio pay?”
Free dividend calculator: estimate your annual dividend income now and years from now, with reinvestment, dividend growth, and price appreciation. No sign-up.
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Stock Average Calculator
“What's my average cost per share across buys?”
Free stock average calculator: combine up to four buys into one average cost per share, test a planned purchase, and see your break-even move. No sign-up.
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Crypto Profit Calculator
“What's my real crypto profit after fees?”
Free crypto profit calculator: see net profit or loss after buy and sell fees, your true return, and the break-even sell price before you trade. No sign-up.
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See your whole financial picture, calmly
Stoia brings everything you own and owe into one clear view. Launching in 2026 on iOS, Android, and the web.