Compound Interest Calculator
Project investment growth with recurring contributions and compounding.
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Explore every MJK Tools calculator in one place. Each tool is built for instant results and real-world financial planning no signup, no paywalls.
Finance & Investment
Mortgage Calculator
Estimate monthly housing costs with principal, interest, tax, and insurance.
Open CalculatorROI Calculator
Calculate net profit and return percentage for investments or projects.
Open CalculatorLoan Payoff Calculator
See debt-free date and interest savings from extra monthly payments.
Open CalculatorRetirement Savings Calculator
Project retirement balance using age, contributions, and expected return.
Open CalculatorInvestment Return Calculator
Measure total return, net gain, and CAGR from beginning and ending values.
Open CalculatorNet Worth Calculator
Track total assets, liabilities, and net worth in one clear snapshot.
Open CalculatorSavings Goal Calculator
Find monthly savings needed to reach a target by your chosen date.
Open CalculatorDebt-to-Income Ratio Calculator
Calculate DTI ratio to assess borrowing readiness and risk.
Open CalculatorBreak-Even Calculator
Calculate sales volume needed to cover fixed and variable costs.
Open CalculatorHome & Loan
Home Affordability Calculator
Estimate home price range based on income, debts, and loan assumptions.
Open CalculatorRefinance Calculator
Compare old and new loan terms with break-even and savings estimates.
Open CalculatorRent vs Buy Calculator
Compare housing costs and equity outcomes over your planned time horizon.
Open CalculatorDown Payment Calculator
Convert down payment percentages into dollar amounts and loan balance.
Open CalculatorAuto Loan Calculator
Estimate car financing payment, interest, and total repayment cost.
Open CalculatorBusiness & Tax
Profit Margin Calculator
Calculate margin percentage and profit dollars from revenue and cost.
Open CalculatorSales Tax Calculator
Compute tax amount and final total from item price and tax rate.
Open CalculatorTip Calculator
Calculate gratuity, total bill, and per-person split instantly.
Open CalculatorDiscount Calculator
Find final sale price and savings from percentage discounts.
Open CalculatorMarkup Calculator
Set selling prices from cost using desired markup percentages.
Open CalculatorEveryday Math
Percentage Calculator
Solve percent-of, what-percent, and percent-change problems quickly.
Open CalculatorAge Calculator
Compute exact age from a birth date to any target date.
Open CalculatorBMI Calculator
Calculate body mass index and standard BMI category ranges.
Open CalculatorCalorie Deficit Calculator
Estimate deficit and projected weight change from intake vs maintenance.
Open CalculatorUnit Converter
Convert between common units for length, weight, and temperature.
Open CalculatorPersonal Finance
Budget Calculator
Build a monthly budget from income and category-based expenses.
Open CalculatorEmergency Fund Calculator
Calculate emergency fund target and timeline based on essentials.
Open CalculatorCredit Card Payoff Calculator
Estimate payoff date and total interest for revolving card balances.
Open CalculatorStudent Loan Calculator
Calculate student loan payment, interest, and repayment duration.
Open Calculator50/30/20 Budget Rule Calculator
Split take-home income into needs, wants, and savings targets.
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