Finance

Finance and business calculators

Every finance tool on OpenTools. Loans, interest, tax, invoices, margins and business maths, worked out in your browser as you type.

All 58 of them are listed below. Each one runs inside this tab, so nothing you open or type is uploaded — see the proof.

• 50/30/20 budget splitSplit stated income into 50%, 30%, and 20% reference amounts.
• ARR calculatorAnnualize a supplied monthly recurring revenue by multiplying by 12.
• Bank statement converterConvert bank statement PDFs to Excel and CSV with balance reconciliation.
• Break-even calculatorCalculate units and sales from fixed cost and unit contribution.
• Budget plannerTotal category expenses and show remaining stated income.
• CAGR calculatorCalculate compound annual growth from beginning value, ending value, and years.
• Cash-runway calculatorDivide available cash by positive monthly net burn.
• Commission calculatorMultiply eligible sales by a supplied commission percentage.
• Compound-interest calculatorCalculate compound growth at an explicit annual frequency.
• Credit-card payoff scenarioSimulate fixed payments using a constant monthly APR fraction.
• Customer churn-rate calculatorDivide customers lost during a period by customers at period start.
• Customer-acquisition cost calculatorDivide supplied acquisition spend by supplied new customers.
• Dated XIRR calculatorFind one annualized rate for irregular dated cash flows.
• Debt-payoff calculatorSimulate fixed monthly payments on one balance with monthly interest.
• Debt-to-income calculatorCalculate stated monthly debt payments as a percentage of stated gross monthly income.
• Discount calculatorEnter an original price and a percentage off to see the amount taken off and the price after the reduction, for a sale tag that shows only the percentage.
• Emergency-fund scenarioMultiply essential monthly expenses by reserve months and add one-off needs.
• Fixed-deposit scenarioProject a fixed principal with explicit compounding frequency.
• Freelance-rate scenarioDivide desired income plus expenses by estimated billable hours.
• Future-value calculatorCalculate a lump sum’s future value with periodic compounding.
• GST arithmetic calculatorAdd a user-supplied GST percentage to a pre-tax amount.
• Hourly-to-salary calculatorAnnualize an hourly rate using explicit weekly hours and working weeks.
• Inflation scenario calculatorProject the future cost of a current amount under constant inflation.
• Inventory-turnover calculatorDivide cost of goods sold by average inventory for a consistent period.
• Invoice late-fee arithmeticCalculate simple monthly late fee using a user-supplied percentage and months.
• Loan EMI calculatorCalculate equal monthly principal-and-interest payment for a fixed-rate amortizing loan.
• Lump-sum growth calculatorProject a one-time amount with monthly compounding.
• Margin calculatorCalculate gross profit and margin from revenue and cost.
• Markup calculatorAdd a markup percentage to cost and show gross margin.
• Monthly contribution growth calculatorProject end-of-month contributions at a constant monthly-equivalent return.
• Mortgage extra payment & savings calculatorCalculate total interest savings and years saved by making extra monthly principal payments.
• Mortgage principal & interest calculatorCalculate fixed monthly principal/interest and total interest.
• MRR calculatorSum customer count × monthly recurring price across supplied plans.
• Net burn-rate calculatorCalculate average monthly cash decline over a supplied period.
• Net-worth calculatorList assets and liabilities one per line as name and amount, in your own browser tab, and the two totals are subtracted, with every line itemised back.
• NPV calculatorDiscount equally spaced cash flows to period zero.
• OFX & QIF statement converterConvert OFX and QIF bank statements to CSV or Excel with transaction preview and balance reconciliation.
• Ordinary-annuity future-value calculatorProject equal end-of-period payments at a constant rate.
• Overtime pay calculatorMultiply hourly rate, overtime hours, and a supplied multiplier.
• Payment fee & invoice calculator (Stripe / PayPal)Calculate merchant processing fees and the reverse invoice amount needed to receive exact net funds.
• Periodic IRR calculatorFind one periodic discount rate whose NPV is approximately zero.
• Present-value calculatorDiscount one future amount using periodic compounding.
• Printable client bill makerLay out a print-ready bill with itemised lines, a tax line and payment instructions. Rupee amounts group in lakh and crore.
• Printable payment receipt makerGenerate official, print-ready payment receipts with reference IDs, payer/payee details, and itemized confirmation.
• Profit calculatorTake fixed and variable costs off revenue to see profit, total costs and margin as a percentage. Margin is reported as undefined when revenue is zero.
• Recurring-deposit scenarioProject fixed end-of-month deposits with an assumed constant rate.
• Retirement corpus scenarioEstimate a retirement-date corpus from expenses, inflation, duration, and return assumptions.
• ROI calculatorEnter what something cost and what it is worth or sold for, and see the net return in money and as a percentage of the cost, worked out in your browser.
• SaaS MRR growth & churn projectionProject recurring revenue trajectory over 12 months factoring in new growth, expansion, and churn.
• Salary to hourly & take-home converterConvert annual salary into monthly, bi-weekly, weekly, daily, and hourly gross & net take-home rates.
• Sales-tax arithmetic calculatorAdd a user-supplied sales-tax percentage to a pre-tax amount.
• Savings-goal contribution calculatorEstimate the end-of-month contribution needed to reach a target.
• Simple-interest calculatorMultiply principal by annual rate by years for simple interest that is never compounded, shown as the interest alone and as principal plus interest.
• Simplified customer LTV calculatorEstimate monthly ARPU × gross-margin fraction ÷ monthly churn fraction.
• Split-bill calculatorEnter the bill, a tip percentage and how many people are paying, from 1 to 100,000, and get the tip, the total and the equal share per person.
• Tip calculatorType the bill before tip and the percentage you mean to leave; you get the tip on its own and the bill plus tip, so a card slip can be checked quickly.
• VAT arithmetic calculatorAdd a user-supplied VAT percentage to a pre-tax amount.
• Weekly timesheet & billable overtime calculatorCalculate daily work hours, 1.5x overtime, meal breaks, hourly pay, and generate a print-ready signed weekly timesheet.