Online Calculators with worked examples and cited sources
Search 1000+ free calculators or browse by hub. Every tool answers a specific money question, shows the formula behind its result, and cites dated public data — so you see exactly how each number is reached. Missing a calculator? Found an error? Tell me — fixes usually ship within a week.
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Loans & Payments
What’s my monthly payment? How much interest will I pay? When is it finally paid off?
Saving & Investing
How much should I save? What will compound interest add? What will it all become?
Investment Returns
Calculators that turn what you invested and what you got back into a total and annualized return you can compare across different assets.
Business & Margins
Calculators for the profitability metrics that run a business — gross, operating, and net margin, markup, and contribution margin.
Taxes
Estimate what you owe. These calculators break down tax on income, sales, and other common situations.
Math
Everyday math, made quick. Straightforward calculators for common arithmetic and number problems.
Everyday Tools
Practical calculators for the small calculations that come up in daily life.
Education
Calculators that help with grades, study planning, and academic measures.
Calculators by hub
Loans & Payments
- 401(k) Loan Payoff Calculator
- Adoption Loan Calculator
- Agricultural Loan Calculator
- Appliance Financing Payoff Calculator
- ATV Loan Calculator
- Account-Based Pension Calculator (Australia)
- Auto Loan Calculator: Car Payment, Tax & Total Cost
- Auto Loan Payoff Calculator
- Balance Transfer Fee Calculator
- BNPL Payoff Calculator
Saving & Investing
- 401(k) Balance Change Calculator
- 401(k) Withdrawal Calculator
- 403(b) Calculator
- 457(b) Calculator
- Adoption Savings Calculator
- Bonus Investment Growth Calculator
- Annuity Accumulation Calculator
- Annuity Payout Calculator
- Superannuation Growth Calculator (Australia)
- Term Deposit Calculator (Australia)
Investment Returns
- Angel Investment Calculator
- Arcade Business ROI Calculator
- Art Investment Calculator
- ATM Machine ROI Calculator
- Axe Throwing Business ROI Calculator
- Batting Cage ROI Calculator
- Billboard ROI Calculator
- Bitcoin Price Change Calculator
- Bond Coupon Payment Calculator
- Bond Future Value Calculator
Business & Margins
- Affiliate Marketing Commission Calculator
- After-Hours Service Surcharge Calculator
- Bonus Percentage of Salary Calculator
- App Development Cost Per Feature Calculator
- App Revenue Per Install Calculator
- ARPU Calculator
- ARR Growth Rate Calculator
- Auction Seller Commission Calculator
- Average Order Value Calculator
- Bakery Margin Calculator
Taxes
- 401(k) Contribution Percent Calculator
- Franking Credits Calculator (Australia)
- Medicare Levy & MLS Calculator Australia (2024-25)
- Super Guarantee Calculator (Australia)
- Automatic Gratuity Calculator
- Précompte Mobilier Calculator (Belgium)
- Bonus Tax Calculator
- 13th Salary Calculator (Brazil)
- FGTS Calculator (Brazil)
- IOF Calculator (Brazil)
Math
- Free Throw Percentage Calculator
- GDP Growth Rate Calculator
- GDP Per Capita Calculator
- Percent Error Calculator
- Percentage Calculator
- Percentage Change Calculator
- Percentage Decrease Calculator
- Percentage Increase Calculator
- Population Growth Rate Calculator
- Rent Increase Calculator
Everyday Tools
- Acupuncture Cost Per Session Calculator
- Air Conditioner Payback Calculator
- Annual vs Monthly Subscription Savings Calculator
- Attic Fan Payback Calculator
- Auction Buyer's Premium Calculator
- Babysitter Cost Per Hour Calculator
- Barber Cost Per Cut Calculator
- Boat Cost Per Trip Calculator
- Booking Fee Calculator
- Bulk Buying Savings Calculator
Education
- Acceptance Rate Calculator
- Annual Tutoring Savings Calculator
- Attendance Rate Calculator
- Classroom Teacher Cost Per Student Calculator
- College Meal Plan Cost Per Meal Calculator
- Course Completion Rate Calculator
- Financial Aid Coverage Rate Calculator
- Gap Year Savings Calculator
- Grade Calculator
- Graduate Degree Salary Premium Calculator
Calculators in other languages
- Calculadoras en Español →
- Calcolatori in Italiano →
- Calculateurs en Français →
- Calculadoras em Português →
- Rechner auf Deutsch →
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