Run the numbers with confidence.
SumStride combines free financial calculators with plain-English examples, formulas and assumptions so you can compare scenarios before making a money decision. Explore mortgages, loans, debt payoff, savings, investing, retirement, pay and everyday calculations.
Explore SumStride calculators
Start with the decision you are trying to make. Each calculator explains its assumptions and gives related tools for the next question.
Home & Mortgage
Mortgage Calculator
Estimate your monthly mortgage payment, taxes, insurance, PMI, HOA fees and total interest.
Open calculator →Home Affordability Calculator
Estimate a home price from income, debts, down payment and mortgage assumptions.
Open calculator →Mortgage Payoff Calculator
See how extra monthly payments can shorten your mortgage and reduce interest.
Open calculator →Loans & Debt
Loan Calculator
Calculate payment, total interest and total repayment for a fixed-rate loan.
Open calculator →Auto Loan Calculator
Estimate your car payment including down payment, trade-in and sales tax.
Open calculator →Credit Card Payoff Calculator
Estimate how long it will take to pay off a credit card and how much interest you may pay.
Open calculator →Debt Payoff Calculator
Estimate payoff time and interest for a debt using a fixed monthly payment.
Open calculator →Savings & Investing
Compound Interest Calculator
See how savings can grow with compounding and monthly contributions.
Open calculator →Savings Calculator
Project a savings balance from a starting amount, monthly deposits and interest rate.
Open calculator →Investment Calculator
Project investment growth and compare your contributions with estimated gains.
Open calculator →Simple Interest Calculator
Calculate simple interest, total interest earned or paid, and ending balance.
Open calculator →Retirement
Retirement Calculator
Project your retirement savings from your current balance and future contributions.
Open calculator →401(k) Calculator
Estimate future 401(k) savings including employee contributions and employer match.
Open calculator →Business
Pay & Work
Everyday
Start with the decision, not the formula
Use the calculators to compare realistic scenarios side by side. Mortgage and debt tools focus on payments and interest; savings and investment tools focus on contributions, time and assumed growth; retirement tools project accumulation under clearly stated assumptions.
Borrowing
Compare payment, term and lifetime interest before focusing on the lowest monthly number.
Saving & investing
Test contribution amounts, time horizons and more than one return assumption.
Retirement
Use projections as planning illustrations, then layer in taxes, inflation, benefits and spending needs.
Every calculator links to its formula, limitations and related tools. For model details across the site, see the Methodology.
How SumStride works
SumStride calculators run directly in your browser. Enter your assumptions, review the estimated result, then adjust the inputs to compare scenarios. For financial decisions, use the estimates as a planning starting point and verify important numbers with your lender, employer, tax professional, financial professional or other relevant source.