Money questions,
clearly answered.
PlainSums turns mortgage, debt, saving, retirement and income scenarios into clear, itemized estimates. No sign-up, visible assumptions, and no invented certainty.
- Free, no sign-up
- Inputs stay in your browser
- Sources and assumptions shown
- Principal & interest
- $2,022.62
- Property tax
- $366.67
- Insurance
- $125.00
- Loan amount
- $320,000
- 30
- Free calculators, no sign-up
- 5
- Money areas, one hub
- $0
- Cost — with no account
- Open
- Assumptions and source notes
Calculator directory
Find the right calculator
Search by money question or narrow the list by topic. Your search stays in this page and is not stored.
30 calculators
- HomeMortgage CalculatorEnter a home price, down payment and rate to see your full monthly payment — principal, interest, property tax and insurance — plus how much interest you'll pay over the life of the loan.
- HomeHome Affordability CalculatorTell us what you can comfortably spend on housing each month and we'll work backwards to the home price that fits — after property tax and insurance.
- HomeRent vs. Buy CalculatorBuying isn't always cheaper than renting. Use this rent or buy calculator to compare the full net cost of each over your time horizon and find the break-even year.
- HomeRefinance CalculatorCompare your current mortgage to a new rate. We'll show the monthly saving, lifetime interest saved, and how long it takes to recoup the closing costs.
- HomeMortgage Payoff CalculatorChoose the mortgage-payoff question you need answered: what an extra monthly payment saves, what a lump sum changes, or how much extra reaches a target timeline.
- DebtLoan CalculatorWorks for any fixed-rate loan. Enter the amount, rate and term to see your monthly payment and exactly how much the loan costs in total.
- DebtAuto Loan CalculatorWork out the monthly payment on a car after your down payment and trade-in, plus the total interest you'll pay over the loan.
- DebtCredit Card Payoff CalculatorCredit card interest compounds fast. See how long your balance takes to clear at a given monthly payment, and how much sooner a bit more would finish it.
- DebtDebt Payoff CalculatorCompare two proven strategies. Avalanche targets the highest rate first to save the most money; snowball clears the smallest balance first for quick wins. Set your debts and an extra amount to throw at them.
- DebtDebt Avalanche CalculatorThe avalanche method attacks the highest interest rate first, which is mathematically the cheapest way out of debt. Enter your balances and the extra you can add each month.
- DebtDebt Snowball CalculatorThe snowball method clears the smallest balance first for a fast, visible win, then rolls that payment onto the next debt. Enter your balances and the extra you can add each month.
- InvestCompound Interest CalculatorCompounding is interest earning interest. Set a starting balance, a monthly contribution and a rate to watch your money grow — and see how much of the result is pure growth.
- InvestSavings Goal CalculatorPlan a fixed savings target from whichever number you do not know: the monthly amount, final balance, time needed or steady annual return.
- InvestInvestment CalculatorProject a portfolio forward from a starting amount and regular contributions. Use it as an investment goal calculator to see whether your current plan reaches the balance you have in mind.
- InvestFIRE CalculatorFinancial Independence, Retire Early. We'll find your 'FIRE number' from your spending using the 4% rule, then estimate how long it takes to reach it.
- InvestMillionaire CalculatorPlan both directions: see when your current pace reaches a million, or choose a deadline and calculate the monthly contribution it requires. Change the target for any wealth milestone.
- InvestInvestment Withdrawal CalculatorModel a portfolio with withdrawals at the start or end of each month, including an annual inflation step-up and transparent lower- and higher-return cases.
- InvestDividend Investment CalculatorSee how a dividend portfolio compounds when you reinvest. Combine yield, dividend growth, price appreciation and contributions to project value and income.
- InvestRoth IRA CalculatorRoth IRA contributions grow tax-free, and qualified withdrawals in retirement aren't taxed. Project your balance from a starting amount and annual contributions.
- Invest529 College Savings CalculatorPlan for college with a 529. Project tax-advantaged growth from your contributions and see how it stacks up against an estimated future tuition bill.
- InvestCD CalculatorSee exactly what a CD pays. Enter your deposit, APY and term to get the maturity value and total interest earned.
- RetireRetirement CalculatorProject your nest egg to retirement age, including any employer match, and see the annual income it could safely provide.
- RetireRetirement Withdrawal CalculatorSee how long a nest egg lasts at a chosen annual withdrawal, with returns still working and withdrawals rising for inflation. Also known as a retirement drawdown or distribution calculator.
- RetireRetirement Income CalculatorTurn a nest egg into a monthly paycheck. We apply a safe withdrawal rate to your savings and add any Social Security or pension to estimate your retirement income.
- RetireCoast FIRE CalculatorCoast FIRE is the point where your invested savings will grow to your full retirement target on their own — no more contributions needed. Find your coast number and whether you've reached it.
- RetireBarista FIRE CalculatorBarista FIRE means semi-retiring: part-time income (and often health benefits) covers some expenses, so your portfolio only needs to fund the gap. See the smaller number you need.
- IncomeTake-Home Pay CalculatorEnter a salary, pick your state and filing status, and see the estimated take-home: 2026 federal income-tax liability, employee payroll taxes and your state's income-tax schedule, itemized line by line.
- IncomeSalary to Hourly CalculatorConvert annual salary and hourly pay, then include paid time off, benefits and work costs to see the value per hour you actually work.
- IncomeTip CalculatorWork out the tip and split the bill in one go. Set the amount, the tip percentage and how many are paying.
- IncomeBonus Tax CalculatorSee what's likely withheld from a work bonus — the 22% federal supplemental rate plus FICA — and how that compares with the tax you actually owe at year end. For planning, not payroll.
Five areas, 30 calculators
Browse by money area, or use the searchable directory above when you already know the question.
Work out what a home really costs — payment, affordability and whether to rent or buy.
- Mortgage
- Affordability
- Rent vs Buy
- Refinance
- Extra payments
Plan a loan, compare payoff strategies, and see the true cost of what you borrow.
- Loan
- Auto loan
- Credit card
- Debt payoff
- Avalanche
- Snowball
Watch compounding do the heavy lifting and map the path to a savings goal.
- Compound interest
- Savings goal
- Investment
- FIRE number
- Millionaire
- Withdrawals
- Dividend
- Roth IRA
- 529 plan
- CD
Project what your nest egg becomes and how long it can last.
- Retirement
- Withdrawal
- Retirement income
- Coast FIRE
- Barista FIRE
Translate a salary into take-home pay and settle the everyday math.
- Take-home pay
- Salary ↔ hourly
- Tip & split
- Bonus tax
We show the math
Every result is a statement: the bottom-line figure, then every line that built it — principal, interest, tax, growth. No black boxes.
Start here
Mortgage Calculator
Enter a home price, down payment and rate to see your full monthly payment — principal, interest, property tax and insurance — plus how much interest you'll pay over the life of the loan.
OpenLoan Calculator
Works for any fixed-rate loan. Enter the amount, rate and term to see your monthly payment and exactly how much the loan costs in total.
OpenCompound Interest Calculator
Compounding is interest earning interest. Set a starting balance, a monthly contribution and a rate to watch your money grow — and see how much of the result is pure growth.
OpenRetirement Calculator
Project your nest egg to retirement age, including any employer match, and see the annual income it could safely provide.
OpenTake-Home Pay Calculator
Enter a salary, pick your state and filing status, and see the estimated take-home: 2026 federal income-tax liability, employee payroll taxes and your state's income-tax schedule, itemized line by line.
OpenThe same plain approach, pointed at math
Seventeen calculators that refuse to just give the answer: long division in the full bracket layout, GCF with factor trees, medians that sort themselves, row reduction with every operation written down — plus printable times-table and place-value charts.
Annual take-home estimates by state
Estimate annual federal and state income-tax liability plus payroll taxes, then view the annual result across a selected number of periods. These are planning estimates, not employer withholding runs.
Money guides
How Much House Can You Really Afford?
A plain-English guide to working out a home price you can comfortably afford — the 28/36 rule, down payments, and the costs people forget.
Mortgage Amortization, Explained
Why your early mortgage payments are almost all interest, how the balance falls over time, and what extra payments actually do.
Debt Snowball vs. Avalanche: Which Wins?
The two most popular debt-payoff strategies compared — which saves the most money, which keeps you motivated, and how to choose.
The 4% Rule, Explained
What the 4% rule is, where it came from, its limits, and how to use it to size the nest egg you need for retirement or financial independence.