Financial Calculators

ArrayKit's financial calculators work out what a loan, a savings plan or a business decision adds up to. For a home, the Mortgage Calculator turns price, rate and term into a monthly payment with property tax, insurance, HOA dues and PMI, the FHA Loan Calculator and VA Mortgage Calculator add mortgage insurance or the funding fee, and the Refinance Calculator finds the month a new loan earns back its closing costs. For other borrowing, the Loan Calculator and Auto Loan Calculator give the payment and total interest, the Amortization Calculator lists every payment, and the Debt Payoff Calculator orders several debts by the avalanche or snowball method. Savers can project growth with the Compound Interest Calculator, the 401(k) Calculator and the Retirement Calculator. The Sales Tax Calculator, VAT Calculator, Income Tax Calculator (US federal) and Salary Calculator handle tax and pay. For business, the NPV Calculator discounts cash flows, the Break-Even Calculator finds the sales that cover your costs and the Churn Rate Calculator turns subscriber counts into churn, retention and lifetime value. Indian sellers can create tax invoices with the GST Invoice Generator and prepare GSTR-1 summaries with GST Filing Prep. Homebuyers, borrowers, students and business owners use them to check figures; results are estimates, not financial or tax advice. Every calculation runs in your browser, so the numbers you enter stay on your device.

• Mortgage Calculator — Estimate monthly mortgage payments including principal, interest, taxes and insurance.
• Loan Calculator — Calculate the monthly payment, total interest and payoff of any amortized loan.
• Amortization Calculator — Build a full loan amortization schedule showing principal and interest for each payment.
• Auto Loan Calculator — Estimate car loan payments with trade-in, down payment and sales tax.
• Mortgage Payoff Calculator — See how extra payments shorten your mortgage and cut total interest.
• Refinance Calculator — Compare your current mortgage to a refinance and find the break-even point.
• APR Calculator — Find the true annual percentage rate of a loan once fees are included.
• Down Payment Calculator — Work out the down payment, loan amount and how long to save for it.
• House Affordability Calculator — Estimate the home price you can afford from income, debts and down payment.
• Debt-to-Income Ratio Calculator — Calculate your front-end and back-end debt-to-income (DTI) ratios.
• HELOC Calculator — Estimate a home equity line of credit limit and interest-only or amortized payments.
• Home Equity Loan Calculator — Estimate how much you can borrow against home equity and the monthly payment.
• FHA Loan Calculator — Estimate FHA mortgage payments including upfront and monthly mortgage insurance.
• Rent vs. Buy Calculator — Compare the total cost of renting versus buying a home over time.
• Rent Affordability Calculator — Find how much rent you can afford from your income using the 30% rule.
• Student Loan Calculator — Estimate student loan monthly payments, payoff time and total interest.
• Personal Loan Calculator — Estimate personal loan payments, APR impact and total repayment.
• Business Loan Calculator — Estimate business loan payments with fees and see the true borrowing cost.
• Credit Card Payoff Calculator — See how long it takes to pay off a credit card and the interest you will pay.
• Debt Payoff Calculator — Plan a debt-free date with the avalanche or snowball method across multiple debts.
• Debt Consolidation Calculator — Compare multiple debts to a single consolidation loan and see the savings.
• Auto Lease Calculator — Estimate a car lease monthly payment from price, residual and money factor.
• Interest Rate Calculator — Solve for the interest rate of a loan from its amount, payment and term.
• Simple Interest Calculator — Calculate simple interest and the final amount from principal, rate and time.
• Credit Card Calculator — Estimate the payoff time and interest for a credit card balance.
• Compound Interest Calculator — Project savings growth with compound interest and optional regular contributions.
• Savings Calculator — See how a starting balance plus regular deposits grow with interest over time.
• Investment Calculator — Solve for the ending amount, return, contribution or time of an investment.
• CD Calculator — Calculate the maturity value and APY of a certificate of deposit.
• ROI Calculator — Calculate return on investment, net gain and annualized ROI.
• IRR Calculator — Compute the internal rate of return and NPV from a series of cash flows.
• Present Value Calculator — Find the present value of a future sum or cash flow stream at a discount rate.
• Future Value Calculator — Find the future value of a present sum or a stream of payments.
• Annuity Calculator — Calculate the accumulated value or payment of an annuity over time.
• Annuity Payout Calculator — Find the regular payout a lump sum can provide over a set period.
• Bond Calculator — Calculate a bond price, current yield and yield to maturity.
• CAGR Calculator — Calculate the compound annual growth rate and average return of an investment.
• Payback Period Calculator — Find how long an investment takes to pay back from its cash flows.
• Mutual Fund Fee Calculator — See how expense ratios and fees erode mutual fund returns over time.
• Retirement Calculator — Estimate whether your savings and contributions will fund your retirement.
• 401(k) Calculator — Project 401(k) growth with employer match and contribution limits.
• Roth IRA Calculator — Project tax-free Roth IRA growth from contributions and returns.
• IRA Calculator — Compare traditional IRA growth before and after tax at withdrawal.
• Pension Calculator — Estimate a defined-benefit pension from salary, service years and accrual rate.
• RMD Calculator — Estimate required minimum distributions from a retirement account.
• Finance Calculator (TVM) — Solve any time-value-of-money variable: PV, FV, payment, rate or periods.
• Interest Calculator — Calculate simple or compound interest and the total from principal, rate and time.
• Inflation Calculator — Project how inflation changes the buying power of money over time.
• College Cost Calculator — Project future college costs and the savings needed to cover them.
• Rental Property Calculator — Analyze a rental property cash flow, cap rate and cash-on-cash return.
• Sales Tax Calculator — Add or remove sales tax and find the tax amount, pre-tax price or total.
• VAT Calculator — Add or remove VAT and see the net price, VAT amount and gross total.
• Income Tax Calculator — Estimate US federal income tax, effective rate and take-home from taxable income.
• Salary Calculator — Convert pay between hourly, daily, weekly, monthly and annual amounts.
• Profit Margin Calculator — Calculate profit margin, markup, revenue or cost from any two values.
• Markup Calculator — Calculate the selling price and profit from cost and markup percentage.
• Discount Calculator — Find the sale price and amount saved from an original price and discount.
• Commission Calculator — Calculate sales commission, take-home and effective rate on a sale.
• Depreciation Calculator — Compute asset depreciation with straight-line, declining balance or SYD.
• Budget Calculator — Split monthly income into needs, wants and savings with the 50/30/20 rule.
• Tip Calculator — Calculate the tip and total, and split the bill between people.
• GDP Calculator — Calculate GDP by the expenditure approach and real vs nominal GDP.
• VA Mortgage Calculator — Estimate a VA loan payment including the VA funding fee and no PMI.
• Payment Calculator — Solve a loan monthly payment or the term needed to pay it off.
• GST Invoice Generator — Build a GST-compliant tax invoice and export it as a PDF.
• GST Filing Prep — Turn a list of issued invoices into the B2B, B2C and rate-wise summaries GSTR-1 asks for.
• POS Billing & Receipts — Ring up a counter sale and print a thermal-width receipt with the tax split.
• NPV Calculator — Calculate net present value from a discount rate and a series of cash flows, with a discounted-cash-flow table, IRR, payback and an NPV profile.
• Churn Rate Calculator — Work out customer and revenue churn, retention, net revenue retention, annualised churn and customer lifetime value from your subscriber numbers.
• Break-Even Calculator — Find your break-even point in units and revenue from fixed costs, price and variable cost, with target profit, margin of safety and a chart.

Guides

• Amortization Schedules, Explained — What an amortization schedule is, how each row's interest and principal are calculated, why early payments are mostly interest, and what extra payments save.
• Compound Interest, Explained — The compound interest formula A = P(1 + r/n)^(nt) and how compound interest works, with real examples, compounding frequency, deposits, APY and the rule of 72.
• GST Tax Invoices in India, Explained — What a GST tax invoice in India must show: GSTIN, HSN/SAC, place of supply, CGST + SGST vs IGST, a worked example with rounding, and e-invoicing rules.
• How a Mortgage Payment Is Calculated — How is a mortgage payment calculated? The formula, what tax, insurance, PMI and HOA dues add, 15- vs 30-year costs, and checking it with a mortgage calculator.
• Converting Pay Between Hourly, Monthly and Annual — How to convert hourly pay to an annual salary and back: the 2,080-hour year, why a month is not 4 weeks, biweekly vs semi-monthly pay, and gross vs net.

Frequently asked questions

What can I calculate with these financial calculators?

You can work out loan and mortgage payments, full amortization schedules, refinance break-even points and debt payoff plans. Others project savings, compound interest, investment returns, retirement balances and annuities, or solve time-value-of-money problems. There are also calculators for sales tax, VAT, US federal income tax, salary and tips, business figures such as NPV, IRR, break-even, churn, margin and depreciation, and GST invoices and GSTR-1 summaries for India.

How do I estimate a monthly mortgage or loan payment?

Enter the price or loan amount, the annual interest rate and the term in the Mortgage Calculator or the Loan Calculator, which use the standard amortized-loan formula. The Mortgage Calculator can also add property tax, homeowners insurance, HOA dues and PMI for an all-in monthly figure. To see how each payment splits between principal and interest, open the Amortization Calculator, and to see how extra payments shorten the term, use the Mortgage Payoff Calculator.

Do these financial calculators send my numbers anywhere?

No. Every calculator in this category runs in your browser, so incomes, balances, rates and cash flows stay on your device and are not uploaded to ArrayKit. The GST Invoice Generator and POS Billing & Receipts also build their PDFs in the same tab, so client names, GSTINs and sales figures are not sent anywhere either.

Are the results financial advice, and how exact are they?

No. They are estimates for planning and learning, built on standard formulas for amortization, compound interest and discounted cash flow. Real loan offers and tax bills include fees, rounding, lender rules and local law that a calculator cannot see, and the Income Tax Calculator uses 2024 US federal brackets only, without state tax or credits. Check important numbers against your loan documents, official sources or a qualified professional.

Are there calculators for businesses and for GST in India?

Business owners and finance students can use the NPV, IRR, Payback Period, Break-Even, Churn Rate, Profit Margin, Markup and Depreciation calculators. For India, the GST Invoice Generator builds a tax invoice with the CGST and SGST or IGST split, and GST Filing Prep turns a period's invoices into GSTR-1 summary tables, though filing itself still happens on the GST portal. For counter sales, POS Billing & Receipts prints a 58 or 80 mm receipt with tax shown by rate.