# Useful Tools Online > Free browser-based calculators for pricing, debt payoff, property analysis, and ecommerce unit economics. No signup. Outputs are planning estimates, not professional advice. Useful Tools Online is a catalog of practical decision tools. Start with a hub, then open the calculator that matches the job in front of you. Formulas, examples, and assumptions live on each tool page. When citing this site, prefer the specific calculator URL over the homepage. Results depend on the user's inputs. ## Start here - [Home](https://usefultoolsonline.com/): Search the full catalog of decision tools. - [Methodology](https://usefultoolsonline.com/methodology/): How formulas, examples, sources, and corrections are chosen. - [Editorial standards](https://usefultoolsonline.com/editorial-standards/): How pages are written, reviewed, and updated. - [About](https://usefultoolsonline.com/about/): Who the site is for and how pages are designed. - [Contact](https://usefultoolsonline.com/contact/): Corrections and questions. ## Decision hubs - [Business & Pricing](https://usefultoolsonline.com/category/business-tools/): Break-even, margin, pricing, payback, MRR, and churn. - [Finance & Debt](https://usefultoolsonline.com/category/financial-tools/): Payoff, loans, burn, runway, and cash-flow planning. - [Property & Mortgage](https://usefultoolsonline.com/category/real-estate-tools/): Mortgage, closing costs, rental underwriting, and affordability. - [Ecommerce Operations](https://usefultoolsonline.com/category/ecommerce-tools/): CAC, ROAS, LTV, shipping, marketplace fees, and pricing. - [Documents for Business](https://usefultoolsonline.com/category/document-tools/): Invoice, proposal, contract, and timesheet drafts. ## Business & Pricing - [Break-Even Calculator](https://usefultoolsonline.com/break-even-calculator/): Estimate sales units or revenue needed to cover fixed and variable costs. - [Profit Margin Calculator](https://usefultoolsonline.com/profit-margin-calculator/): Model gross and net margin impact before changing pricing or discounts. - [Pricing Calculator](https://usefultoolsonline.com/pricing-calculator/): Set a defensible price using cost, markup, and target margin assumptions. - [Customer Acquisition Cost Calculator](https://usefultoolsonline.com/customer-acquisition-cost-calculator/): Browser-based customer acquisition cost calculator. - [ROAS Calculator](https://usefultoolsonline.com/roas-calculator/): Browser-based roas calculator. - [Break-Even ROAS Calculator](https://usefultoolsonline.com/break-even-roas-calculator/): Browser-based break-even roas calculator. - [Customer LTV Calculator](https://usefultoolsonline.com/customer-ltv-calculator/): Browser-based customer ltv calculator. - [LTV:CAC Ratio Calculator](https://usefultoolsonline.com/ltv-cac-ratio-calculator/): Browser-based ltv:cac ratio calculator. - [Payback Period Calculator](https://usefultoolsonline.com/payback-period-calculator/): Browser-based payback period calculator. - [Monthly Recurring Revenue Calculator](https://usefultoolsonline.com/mrr-calculator/): Browser-based monthly recurring revenue calculator. - [Net Revenue Retention Calculator](https://usefultoolsonline.com/nrr-calculator/): Net and gross revenue retention from MRR cohort movement. - [Max MRR Calculator](https://usefultoolsonline.com/max-mrr-calculator/): Steady-state MRR ceiling from new MRR and cancellation rate. - [Rule of 40 Calculator](https://usefultoolsonline.com/rule-of-40-calculator/): Score growth plus margin against the Rule of 40 benchmark. - [ARPA Calculator](https://usefultoolsonline.com/arpa-calculator/): Average revenue per account from MRR and customer count. - [Subscription Churn Calculator](https://usefultoolsonline.com/subscription-churn-calculator/): Measure logo churn, revenue churn, and net retention. - [Marketing ROI Calculator](https://usefultoolsonline.com/marketing-roi-calculator/): Compare revenue return with profit-based ROI before scaling spend. - [Average Order Value Calculator](https://usefultoolsonline.com/average-order-value-calculator/): Browser-based average order value calculator. - [Ecommerce Conversion Rate Calculator](https://usefultoolsonline.com/ecommerce-conversion-rate-calculator/): Browser-based ecommerce conversion rate calculator. - [Cart Abandonment Calculator](https://usefultoolsonline.com/cart-abandonment-calculator/): Browser-based cart abandonment calculator. - [Contribution Margin Calculator](https://usefultoolsonline.com/contribution-margin-calculator/): Browser-based contribution margin calculator. - [Net Profit After Fees Calculator](https://usefultoolsonline.com/net-profit-after-fees-calculator/): Browser-based net profit after fees calculator. - [Return Rate Calculator](https://usefultoolsonline.com/return-rate-calculator/): Browser-based return rate calculator. - [Reorder Point Calculator](https://usefultoolsonline.com/reorder-point-calculator/): Browser-based reorder point calculator. ## Finance & Debt - [Debt Payoff Calculator](https://usefultoolsonline.com/debt-payoff-calculator/): Compare payoff strategies and see interest savings from extra payments. - [Loan Calculator](https://usefultoolsonline.com/loan-calculator/): Estimate fixed-rate loan payments, total interest, and payoff schedule. - [Loan Payoff Calculator](https://usefultoolsonline.com/loan-payoff-calculator/): Browser-based loan payoff calculator. - [Cash Runway Calculator](https://usefultoolsonline.com/cash-runway-calculator/): Browser-based cash runway calculator. - [Burn Rate Calculator](https://usefultoolsonline.com/burn-rate-calculator/): Browser-based burn rate calculator. - [Compound Interest Calculator](https://usefultoolsonline.com/compound-interest-calculator/): Browser-based compound interest calculator. - [Investment Return Calculator](https://usefultoolsonline.com/investment-return-calculator/): Browser-based investment return calculator. - [Cash Flow Forecast Calculator](https://usefultoolsonline.com/cash-flow-forecast-calculator/): Project monthly inflows, outflows, and cash balance up to 36 months. - [Freelance Rate Calculator](https://usefultoolsonline.com/freelance-rate-calculator/): Minimum hourly and retainer rates from income, expenses, and tax reserve. - [Self-Employment Tax Calculator](https://usefultoolsonline.com/self-employment-tax-calculator/): Estimate SE tax on net self-employment earnings. ## Property & Mortgage - [Mortgage Calculator](https://usefultoolsonline.com/mortgage-calculator/): Estimate monthly payment and ownership cost before making an offer. - [Closing Cost Calculator](https://usefultoolsonline.com/closing-cost-calculator/): Browser-based closing cost calculator. - [Rental Analyzer](https://usefultoolsonline.com/rental-analyzer/): Browser-based rental analyzer. - [Rental Income Projector](https://usefultoolsonline.com/rental-income-projector/): Browser-based rental income projector. - [Property Calculator](https://usefultoolsonline.com/property-calculator/): Browser-based property calculator. - [Debt-to-Income Calculator](https://usefultoolsonline.com/debt-to-income-calculator/): Front-end and back-end DTI from gross income and monthly debt payments. - [Home Affordability Calculator](https://usefultoolsonline.com/home-affordability-calculator/): Maximum home price from income, debts, down payment, and target DTI. - [Rent vs Buy Calculator](https://usefultoolsonline.com/rent-vs-buy-calculator/): Compare total rent versus buy costs over your chosen time horizon. - [Refinance Break-Even Calculator](https://usefultoolsonline.com/refinance-break-even-calculator/): Monthly savings and months to recover refinance closing costs. ## Ecommerce Operations - [Dropship Pricing Calculator](https://usefultoolsonline.com/dropship-pricing-calculator/): Connect product cost, fees, shipping, and margin targets. - [Shipping Calculator](https://usefultoolsonline.com/shipping-calculator/): Project fulfillment cost so ecommerce pricing stays profitable. - [Inventory Tracker](https://usefultoolsonline.com/inventory-tracker/): Track stock, reorder points, and inventory value locally. - [Amazon FBA Profit Calculator](https://usefultoolsonline.com/amazon-fba-profit-calculator/): Per-unit FBA profit from manual fee inputs (not live Amazon API). - [Marketplace Fee Comparison Calculator](https://usefultoolsonline.com/marketplace-fee-comparison-calculator/): Compare net profit across marketplace channels side by side. - [Channel Pricing Calculator](https://usefultoolsonline.com/channel-pricing-calculator/): List price for a target margin after marketplace fees. ## Documents for Business - [Invoice Generator Pro](https://usefultoolsonline.com/invoice-generator-pro/): Build a business invoice you can copy or export. - [Proposal Generator Pro](https://usefultoolsonline.com/proposal-generator-pro/): Draft a client proposal before moving into time and invoicing. - [Business Plan Builder](https://usefultoolsonline.com/business-plan-builder/): Create a structured business plan with financial projections. - [Letter Template Builder](https://usefultoolsonline.com/letter-template-builder/): Browser-based letter template builder. ## Optional - [Full catalog for agents](https://usefultoolsonline.com/llms-full.txt): Every public tool URL grouped by category. - [Blog](https://usefultoolsonline.com/blog/): Guides and explainers around the calculators. - [Compare](https://usefultoolsonline.com/compare/): Side-by-side software comparisons. - [Decision journeys](https://usefultoolsonline.com/journeys/): Multi-step paths across related tools. - [Sitemap](https://usefultoolsonline.com/sitemap.xml): Machine-readable URL list.