Financial math
you can verify.
17 calculators that show every step. Every assumption stated, every default overridable. All math runs client-side — your data never leaves your browser.
Paycheck Calculator
LIVEEvery calculator, one place
Click a category to filter, or browse them all. Each tool shows the math behind the number.
Mortgage Payment
Monthly P&I, taxes, insurance, PMI. Full amortization.
Home Affordability
Max purchase price from income, debts, down payment.
State Tax & Housing
50-state scatter plot: property tax vs. income tax.
Compound Interest
Contributions + compound growth with yearly breakdown.
Investment Return
Growth projections with dividends, inflation, CAGR.
Savings Goal
Monthly savings needed to reach your target on time.
Retirement Calculator
Drawdown analysis with Social Security estimates.
401(k) Calculator
Employer match, limits, catch-up, projected balance.
Roth IRA Calculator
Roth vs. Traditional with MAGI phaseouts.
Tax Bracket
Federal brackets with effective + marginal rates.
Paycheck
Take-home after federal, state, FICA for all 50 states.
Take-Home Pay Map
Interactive 50-state map: best vs. worst states for your salary.
Capital Gains
Short/long-term rates, NII surtax, net proceeds.
Self-Employment Tax
SE tax, estimated quarterly payments for freelancers.
Debt Payoff
Avalanche vs. snowball with debt-free date.
Auto Loan
Payment, total interest, amortization with trade-in.
Student Loan
Standard, graduated, extended, IDR plan comparison.
Why PennyCalc
Built by a PE professional who models leveraged buyouts for a living. These are the tools we wish existed.
Visible Math
Every calculator shows amortization schedules, bracket breakdowns, and year-by-year projections. Not just the answer — the proof.
Your Assumptions
PMI rates, tax filing status, employer match — every default can be changed. Plug in your real numbers for real answers.
Privacy First
All math runs in your browser. No accounts, no email capture, no server calls. Your financial data never leaves your device.
Guides & References
Deep dives, worked examples, and reference tables.
Financial Glossary
50+ terms in plain English
Tax2026 Tax Brackets
Rates, deductions, worked examples
TaxTax Brackets Hub
Current year + 1913-2026 history chart
Retirement2026 401(k) Limits
Deferrals, catch-up, mega backdoor
RetirementRoth vs. Traditional IRA
Side-by-side tax math
DebtAvalanche vs. Snowball
Worked example with $47K debt
InvestingCompound Interest
Rule of 72 + growth tables
IncomeSalary After Taxes
$50K–$200K take-home breakdowns
TaxSelf-Employment Tax
15.3% SE tax, quarterly payments
Frequently Asked Questions
Are PennyCalc's calculators really free?
How accurate are the calculations?
What makes PennyCalc different?
Do you store my financial information?
Can I use PennyCalc for tax planning?
Built by people who use these tools
PennyCalc was started by a private-equity analyst who got tired of black-box financial calculators. Every tool models the math the same way we model it at work — transparently.
About the team