# CalculatorFree.io > Free financial calculators for loans, mortgages, savings, investments, retirement, taxes, and business finance, complemented by selected general-purpose calculators. Financial calculators are the site's primary focus. The links below are a curated starting point; the calculator directory provides the complete tool selection. Pages include formulas, worked examples, assumptions, and applicable source notes. Interactive calculations run in the browser and require JavaScript. Default inputs and results are illustrations; estimates depend on the entered values, selected mode, timing, and rounding conventions. Future return and inflation presets are editable assumptions. General financial mathematics is not a jurisdiction-specific tax model; tax and retirement rules apply only to the jurisdictions and years stated on each page. Currency conversion uses a dated bundled reference snapshot or a manually entered rate. Consult the methodology and each tool's scope before interpreting a result. ## Start here - [Financial calculator directory](https://calculatorfree.io/financial-calculator.html): Browse the site's financial tools and supporting general-purpose calculators. - [Calculation methodology and sources](https://calculatorfree.io/methodology.html): Validation approach, illustrative defaults, data versions, timing, rounding, and model limitations. - [Financial glossary](https://calculatorfree.io/glossary/): Plain-English financial definitions with formulas, examples, sources, and links to relevant calculators. - [Canonical sitemap](https://calculatorfree.io/sitemap.xml): Complete canonical page inventory; calculator modes share their parent page's canonical URL. ## Mortgage and housing - [Mortgage Calculator](https://calculatorfree.io/mortgage-calculator.html): Estimate payments and ownership costs, model extra principal payments, and compare biweekly payments. Monthly mode automatically estimates PMI from original LTV, an assumed credit-score range and loan term using a dated National MI base-rate card; actual quotes can be entered manually. The requested 80% cancellation model uses the lower of purchase price and original appraisal. Biweekly mode excludes PMI and ownership expenses; cash purchases retain ownership-cost estimates without a loan schedule. - [Mortgage Payoff Calculator](https://calculatorfree.io/mortgage-payoff-calculator.html): Compare repayment strategies using the current balance or original loan details, including extra payments and biweekly payments. ## Loans and debt - [Loan Calculator](https://calculatorfree.io/loan-calculator.html): Calculate fixed-rate amortized payments, deferred single repayments, or zero-coupon bond present values. - [Debt Payoff Calculator](https://calculatorfree.io/debt-payoff-calculator.html): Compare highest-interest-first avalanche and smallest-balance-first snowball strategies using entered debts and payments. ## Savings and investments - [Compound Interest Calculator](https://calculatorfree.io/compound-interest-calculator.html): Opens in Compound Growth for starting money, monthly or annual contributions, compounding and contribution timing. Equivalent Interest Rate conversion remains a separate mode. - [Savings Calculator](https://calculatorfree.io/savings-calculator.html): Project savings growth, solve the monthly deposit needed for a goal, or estimate time to reach a target. - [ROI Calculator](https://calculatorfree.io/roi-calculator.html): Calculate total and annualized investment returns using an investment length or two dates. - [IRR Calculator](https://calculatorfree.io/irr-calculator.html): Estimate annual IRR from modeled periodic cash flows or unequal amounts at successive year ends. Freely chosen calendar transaction dates are handled by Average Return's Dated Cash Flows mode. - [Average Return Calculator](https://calculatorfree.io/average-return-calculator.html): Compare arithmetic and geometric returns; Dated Cash Flows calculates an annual money-weighted return from real YYYY-MM-DD transaction dates and amounts, showing multiple roots when found. - [CD Calculator](https://calculatorfree.io/cd-calculator.html): Estimate certificate of deposit maturity value and after-tax interest under entered assumptions. - [CAGR Calculator](https://calculatorfree.io/cagr-calculator.html): Annualize growth between beginning and ending values, or solve for an implied beginning or ending value, without intermediate cash flows. ## Financial mathematics - [Finance Calculator](https://calculatorfree.io/finance-calculator.html): Solve time-value-of-money variables under the entered payment, rate and timing assumptions. - [Future Value Calculator](https://calculatorfree.io/future-value-calculator.html): Estimate future value from starting principal and payments under the selected timing and rate. - [Present Value Calculator](https://calculatorfree.io/present-value-calculator.html): Discount a future amount and modeled payments to a present value. ## Retirement planning - [401(k) Calculator](https://calculatorfree.io/401k-calculator.html): U.S. planning under fixed 2026 contribution and age-based catch-up rules. Limits combine traditional and Roth deferrals; applicable high-earner catch-up must be Roth. The growth projection does not split their tax treatments or project future legal limit changes. - [Retirement Calculator](https://calculatorfree.io/retirement-calculator.html): Estimate required savings, periodic saving, monthly withdrawals, or savings longevity under stated assumptions. - [IRA Calculator](https://calculatorfree.io/ira-calculator.html): Compare U.S. Traditional IRA, Roth IRA and taxable saving under fixed 2026 contribution limits and entered tax assumptions; eligibility is not inferred. - [Roth IRA Calculator](https://calculatorfree.io/roth-ira-calculator.html): Compare qualified U.S. Roth IRA growth with equivalent after-tax saving in a taxable account using fixed 2026 contribution rules. - [RMD Calculator](https://calculatorfree.io/rmd-calculator.html): Estimate U.S. required minimum distributions for traditional IRA and other eligible non-Roth owner balances using supported IRS factors. Roth IRA owners, designated Roth plan balances for 2024 onward, inherited accounts and employer-plan deferrals are excluded. - [Social Security Calculator](https://calculatorfree.io/social-security-calculator.html): Ideal-age planning uses FRA PIA in age-62 dollars, assumed COLA while waiting and after claiming, and a nominal discount rate. Comparison mode uses separately entered nominal claim-date benefit quotes. Earnings records and benefit statements are not retrieved. ## Tax and income - [Income Tax Calculator](https://calculatorfree.io/tax-calculator.html): Estimate selected 2025 or 2026 U.S. federal income tax and withholding balance, including entered eligible passive NIIT income, MFS spouse itemization and year-specific AMT adjustments. The 2026 active-QBI minimum requires the stated eligibility; this is not a complete return-preparation engine. - [Salary Calculator](https://calculatorfree.io/salary-calculator.html): Convert pay frequencies and compare unadjusted pay with holiday- and vacation-adjusted pay. - [Take-Home Paycheck Calculator](https://calculatorfree.io/take-home-pay-calculator.html): Estimate pay using 2026 U.S. federal rules and explicit state/local effective-rate assumptions; this is not a complete state or city tax engine. ## Mortgage decision tools - [PMI Calculator](https://calculatorfree.io/pmi-calculator.html): Conventional borrower-paid PMI estimates, original/current LTV and separate 80% request, scheduled 78% and midpoint checks; U.S. rules and dated insurer assumptions are stated. - [Biweekly Mortgage Payment Calculator](https://calculatorfree.io/biweekly-mortgage-calculator.html): Compare 26 credited payments per year, ordinary monthly and equal-budget monthly alternatives; not an exact 14-day calendar model. - [Discount Points Calculator](https://calculatorfree.io/discount-points-calculator.html): Enter actual loan quotes; compare cash-flow and balance-aware break-even, upfront fees and holding-period borrowing costs. ## Business finance - [Margin Calculator](https://calculatorfree.io/margin-calculator.html): Solve profit, revenue, cost, margin, or markup; separate modes estimate stock and foreign-exchange margin requirements. - [Markup Calculator](https://calculatorfree.io/markup-calculator.html): Calculate selling price or cost and convert between markup on cost and margin on revenue. - [Break-Even Calculator](https://calculatorfree.io/break-even-calculator.html): Estimate operating break-even under entered cost and pricing assumptions. - [Depreciation Calculator](https://calculatorfree.io/depreciation-calculator.html): Compare supported depreciation methods and book-value schedules; calculated book value is not a market-price estimate. ## Financial reference - [Compound interest](https://calculatorfree.io/glossary/compound-interest/): How interest accumulates on principal and previous interest, with a worked example. - [Annual percentage rate (APR)](https://calculatorfree.io/glossary/apr/): Meaning, conventions, and limitations when comparing borrowing costs. - [Annual percentage yield (APY)](https://calculatorfree.io/glossary/apy/): Effective annual yield and its relationship to compounding assumptions. - [Inflation](https://calculatorfree.io/glossary/inflation/): Price-level changes, purchasing power, and the distinction between historical data and future assumptions. ## Supporting general-purpose calculators - [Percentage Calculator](https://calculatorfree.io/percentage-calculator.html): Calculate a percentage of a number, percentage change, or one number as a percentage of another. - [Scientific Calculator](https://calculatorfree.io/scientific-calculator.html): Evaluate real-number arithmetic, powers, roots, trigonometric functions, logarithms, and factorials. ## Optional - [About CalculatorFree.io](https://calculatorfree.io/about.html): The site's independent planning tools and links to its methodology. - [Privacy](https://calculatorfree.io/privacy.html): How calculator inputs, share links, advertising, and reference-rate data are handled.