Free Online Calculators
22 free financial calculators for real-world money decisions — mortgage payoff, retirement, taxes, investing, and payroll. Every calculator is updated for 2026 IRS rates, works on any device, and runs entirely in your browser.
Above, use our built-in scientific calculator for quick math with trigonometry, logarithms, exponents, and memory functions. Below, browse all 22 specialized calculators by category.
All Calculators by Category
Mortgage & Debt
Retirement & Savings
Tax Calculators
About MultiCalculators.net
MultiCalculators.net is a free online calculator library built for real financial decisions. Every tool uses the exact formulas the IRS, banks, and financial planners rely on — with 2026 tax rates, contribution limits, and interest formulas built in.
What you can calculate
Our 22 specialized calculators cover the money questions most people actually need answered:
- Mortgage & loans: Payoff timelines with extra payments, PMI costs and cancellation, and recast vs. lump-sum comparisons.
- Debt payoff: Snowball vs. avalanche strategies across multiple debts, and credit card payoff timelines.
- Retirement: 401(k) projections with employer match, Roth IRA tax-free growth, 529 college savings, and FERS federal annuities.
- Investing: Compound interest projections, dividend income with DRIP, stock profit after capital gains tax.
- Taxes: Sales tax (forward and reverse), capital gains with NIIT, self-employment tax, 1099 contractor breakdowns, and overtime tax.
- Payroll & business: Pay raise impact, markup and margin, and time-and-a-half overtime pay.
Why our calculators are different
Most online calculators are either oversimplified (ignore taxes, use last year’s rates) or lock the useful features behind a signup. Ours don’t. Every calculation runs in your browser using JavaScript — nothing is sent to a server, nothing is stored, nothing is shared. You’ll never see an ad, a paywall, or a “create free account to continue” popup.
Frequently asked questions
Are these calculators free?
Yes. All 22 calculators plus the scientific calculator at the top of this page are 100% free. No sign-up, no email required, no hidden fees.
Are they updated for 2026?
Yes. Every tax calculator uses 2026 IRS federal income tax brackets, standard deductions ($15,000 single / $30,000 MFJ), Social Security wage base ($184,500), 401(k) contribution limits ($24,500), Roth IRA limits ($7,500 / $8,600 age 50+), and standard mileage rate ($0.70/mile).
Is my data private?
Yes. All calculations happen entirely in your browser. Nothing you enter is transmitted, stored, or logged. Your data never leaves your device.
How accurate are the results?
Our calculators use the exact formulas the IRS, banks, and financial institutions rely on. They provide highly accurate estimates for planning purposes. For legal, tax, or investment decisions, always consult a licensed professional.
Do they work on mobile?
Yes. Every calculator is fully responsive and works on desktop, tablet, and mobile devices. No app to download.