Free Online Finance Calculators
Run the numbers on loans, mortgages and pay — privately.
Your files never leave your device. No upload. No sign-up.
Money calculations are the last thing you want sitting on a third party's server. SwiftTooly's finance tools compute amortization schedules, compound growth, take-home pay and sales tax locally in your browser. You can plug in salaries, debts and interest rates with confidence that the numbers go no further than your own machine.
5 finance
Loan Calculator
Estimate monthly loan payments, total interest, and total cost.
Mortgage Calculator
Estimate your monthly mortgage payment based on price, down payment, rate, and term.
Compound Interest Calculator
See how your savings grow with compounding interest and regular contributions.
Salary Calculator
Convert any salary between hourly, weekly, monthly, and yearly amounts.
Sales Tax Calculator
Add sales tax to a price or extract tax from a gross amount.
Why use SwiftTooly's finance
Sensitive by default
Salary, debt and interest figures never leave your browser. No account, no profile, no leak.
Standard formulas
Amortization, compound interest and tax math follow the same equations your bank uses.
Transparent breakdowns
See the principal vs interest split, monthly vs total cost, and effective rates.
Globally usable
Work in any currency — formatting follows the number; we never assume a country.
Browser-based vs upload-to-server
SwiftTooly (browser)
Loan and interest math runs as a small JavaScript loop in the page. Your inputs and the schedule never touch a server.
Typical upload-to-server tools
Many “free” finance calculators are lead-gen funnels — your salary, debt, and email feed into a marketing database before you ever see a result.
Frequently asked questions
- Are these calculators a substitute for financial advice?
- No. They produce mathematically correct results for the formulas they use, but real-world loans, taxes and salaries depend on local rules. Use the numbers as a starting point, not as professional advice.
- Which compounding frequencies are supported?
- The Compound Interest Calculator supports annual, semi-annual, quarterly, monthly and daily compounding, plus optional recurring contributions.
- Does the mortgage calculator include taxes and insurance?
- It focuses on principal and interest. Property tax, insurance and PMI vary by jurisdiction — add them as separate line items if you need a full PITI estimate.
- Will my salary or loan numbers be logged?
- Never. The calculation happens in your browser and we don't attach the input to any analytics event.