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The complete Breakeven Math calculator library.

Retirement and tax planning, mortgage and real-estate economics, startup equity and compensation. Each page explains the method behind its numbers, and every calculation runs in your browser.

Runs locally in your browser • Zero financial data stored
Tools

All Calculators

Every published Breakeven Math calculator, grouped by the decision it supports. Most apply US federal and state rules; one covers the Australian Age Pension.

Retirement Wealth Company Match

401(k) Employer Match & True-Up

Per-paycheck contributions needed to capture the full employer match, with vesting schedules and true-up provisions.

Calculate 401(k) Match
Tax Strategy Form 8606

Backdoor Roth & Pro-Rata Modeler

Calculate taxable conversion ratios under the IRS Form 8606 Pro-Rata Rule, track non-deductible basis, and model 401(k) reverse rollover shelters.

Calculate Pro-Rata Tax
Retirement Tax 2026 Limits

Solo 401(k) vs. SEP IRA Contributions

2026 Solo 401(k) and SEP IRA contribution limits and deductions for self-employed and S-Corp owners, side by side with upfront tax savings.

Compare 401(k) & SEP
Tax Strategy Triple-Tax

HSA Triple-Tax & Stealth IRA Modeler

Calculate upfront income and FICA 7.65% tax deductions, 30-year tax-free compounding, and the stealth IRA receipt shoebox strategy.

Model HSA Tax Savings
Tax Shelter Triple-Tax-Free

HSA "Stealth IRA" Wealth Modeler

Calculates triple-tax-free HSA compound growth vs taxable brokerage accounts utilizing the shoebox receipt reimbursement strategy.

Model HSA Growth
Open Enrollment Plan Compare

HDHP (HSA) vs. PPO Calculator

Compare High Deductible HDHP + HSA vs Traditional Low Deductible PPO plans: model payroll premium savings, employer HSA seeds, and 3-tier medical spending stress tests.

Compare HDHP vs PPO
Education Wealth State Deduction

529 College Savings & State Tax

529 plan growth and state tax deduction savings, compared against a taxable brokerage account, with SECURE 2.0 Roth rollovers.

Calculate 529 Growth
Tax Strategy Wash-Sale Rule

Tax-Loss Harvesting

Tax saved by harvesting capital losses under 2026 rules: short- and long-term offsets, the $3,000 limit, carryforwards, NIIT, and the wash-sale rule.

Calculate Tax Offsets
Retirement Wealth Centrelink

Centrelink Age Pension & Deeming Calculator (Australia)

Estimate your fortnightly Centrelink Age Pension under both the assets and income tests, including deeming on financial assets and the Work Bonus.

Calculate Age Pension
State Tax Relocation

State-to-State Tax & Relocation Modeler

Net tax savings weighed against the costs of moving to a no-income-tax state such as Texas, Florida, Washington, or Nevada, including property and sales tax.

Compare States
Business Tax 6,000+ lbs GVWR

Section 179 Heavy Vehicle Deduction (over 6,000 lbs GVWR)

2026 first-year Section 179 and bonus depreciation deductions and tax savings for business vehicles over 6,000 lbs GVWR, using IRS Pub 946 limits.

Calculate Section 179
Startup Equity Form 6251

ISO vs. NSO Stock Options & AMT

Calculate your Alternative Minimum Tax (AMT) liability when exercising Incentive Stock Options (ISOs) vs Non-Qualified Stock Options (NSOs) and model Form 8801 AMT credits.

Calculate AMT Liability
Equity Tax Form 2210

RSU Tax Withholding & Underpayment Penalty

The federal tax a 2026 RSU vest adds, the shortfall left by 22% supplemental withholding, and the Form 2210 underpayment penalty it could trigger.

Calculate RSU Shortfall
Compensation Two Offers

Job Offer Comparison: Net Pay After Work Costs

Two job offers compared after an assumed tax rate and the commuting, childcare, and pet care costs each role adds, plus the raise that would make them equal.

Compare Job Offers
Tax & Career 3-Way Compare

W-2 vs. 1099 vs. C2C (S-Corp)

Net take-home pay, total tax, and business deductions compared across W-2, 1099, and C2C (S-Corp) structures, including the reasonable-salary split.

Compare Tax Shelters
Agency & 1099 Rate Modeler

Freelance Hourly Rate & Retainer Calculator

Calculate true billable hourly rates, factor in 15.3% self-employment taxes, 60% billable utilization buffers, and value-based retainers.

Calculate Freelance Rate
Real Estate DTI & Max Loan

Home Affordability Calculator

The maximum home price under a 36% debt-to-income limit, from income, monthly debts, down payment, and interest rate.

Calculate Affordability
Real Estate PMI vs Rate Premium

Physician Loan vs Conventional Mortgage Calculator

Run both amortization schedules side by side: months of PMI until the 80% or 78% threshold, interest over your holding period, and the earnings you give up on a larger down payment.

Compare Loans
Mortgage Math Principal & Interest

Mortgage Amortization Schedule

Monthly payment, total interest, and a year-by-year schedule of interest, principal, and balance for a fixed-rate mortgage.

View Amortization Schedule
Refinance Term Reset

Refinance True Breakeven & Term Reset

Months to recover refinance closing costs, and the extra years and interest added when a refinance restarts the loan term.

Calculate True Breakeven
Mortgages & Rates Rate Cuts

Fed Rate Cut Mortgage Refinance Savings

Monthly and lifetime savings when mortgage rates fall, with closing-cost break-even timelines.

Calculate Refi Savings
Mortgage Strategy Lump-Sum Recast

Mortgage Recast Calculator

New monthly payment after a lump-sum principal payment and recast, with per-$10,000 tables and how a recast differs from a refinance or prepaying.

Compare Recast Options
Rate Buy-Down Points Breakeven

Mortgage Discount Points

Calculate whether paying 1 to 2 discount points upfront at closing actually saves money before you move or refinance into lower market rates.

Calculate Points Breakeven
Real Estate Wealth Cash-on-Cash

BRRRR Real Estate Modeler

Model purchase price, rehab budgets, 75% ARV cash-out refinances, capital recapture, DSCR coverage, and cash-on-cash ROI.

Underwrite BRRRR Deal
Renter Economics Move Breakeven

Rent Hike vs. Moving Cost

Determine if moving to a cheaper apartment actually saves money once moving trucks, broker commissions, and security deposit friction are counted.

Calculate Rent Breakeven
Original Research

The ISO AMT trap, measured across 500 scenarios

We modelled 500 startup-employee exercise scenarios to find where paper wealth turns into a real Alternative Minimum Tax bill.

Read the study →
Methodology & Standards

How these calculators are built, verified, and run

How the calculators handle your inputs, where their figures come from, and how they are checked.

01

Client-Side Isolation

Every calculation occurs entirely within your browser's local memory using pure JavaScript and local state. When you calculate tax liability or debt amortization, your financial inputs never leave your browser.

02

Sourced Figures

Tax limits, rates, and thresholds are taken from agency publications such as IRS revenue procedures, notices, and publications, and Services Australia for the Age Pension. Most pages list the publications their figures come from.

03

How Figures Are Checked

When a page is updated, its worked examples and tables are regenerated by running the calculator's own code rather than typed by hand, and its tax figures are rechecked against their sources.

Learn more about our team and editorial standards: Read About Breakeven Math →