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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.

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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
Vehicles Total cost breakeven

EV vs Gas vs Hybrid Cost Calculator

Total cost of an electric, hybrid or gas car over the years you keep it, the year a pricier car pays for itself, and the annual mileage at which the EV matches gas.

Compare Cars
Vehicles Lease vs loan

Car Buy vs Lease Calculator

Net cost of leasing a car repeatedly against buying it with a loan over 3, 6 or 9 years, including residual, money factor, fees, mileage and resale, and the year buying overtakes.

Compare Buy vs Lease
Vehicles 0% APR vs rebate

Pay Cash vs Finance a Car: 0% APR vs Rebate

Pay cash or finance and keep the cash invested, the rate a 0% offer really costs when it means giving up a rebate, and the return at which financing comes out ahead.

Compare Offers
Vehicles Breakeven repair quote

Repair vs Replace Car Calculator

The yearly cost of repairing and keeping an older car against replacing it, over the years the repair buys, and the repair quote at which replacing becomes cheaper.

Compare Repair vs Replace
Tax Give vs sell

Charitable Real Estate Donation Calculator

The deduction, yearly AGI limit and five-year carryover for giving appreciated real estate to a charity or selling it at a bargain, and the cash difference from selling it.

Compare Gift vs Sale
Retirement 62 vs 67 vs 70

Social Security Claiming Age Calculator

The age at which waiting until 70 pays more in total than claiming at 62, a couple's spousal and survivor benefits, and a pension lump sum against its annuity.

Compare Ages
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 §415(c)

Mega Backdoor Roth Calculator

After-tax 401(k) room under the annual additions limit once deferrals and employer money are counted, with catch-up kept outside it, and the cost of leaving the money unconverted.

Find After-Tax Room
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
Retirement Defined benefit

Cash Balance Plan Contribution Calculator

Estimated yearly cash balance credit for a business owner from the 2026 benefit limit, age, pay and the 10-year phase-in, plus the 401(k) deferral and the tax saved.

Estimate Contributions
Retirement 401(k) vs IRA

Solo 401(k) Rental Property Calculator

Cash flow, cash-on-cash return and 20-year value for a rental bought in a Solo 401(k), and the unrelated business income tax an IRA would owe on the same property.

Model the Rental
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
Real Estate Net worth after N years

401(k) Loan vs PMI Down Payment Calculator

Borrow from a 401(k) to reach 20% down, or pay PMI: the PMI and mortgage interest avoided, the 401(k) gap, and the tax on loan interest, with spending held equal.

Compare Paths
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
Real Estate Breakeven return

Extra Mortgage Payment vs Investing Calculator

Pay extra principal or invest the same amount: interest saved, payoff date, after-tax balances with equal spending, and the return at which the two come out equal.

Compare Paths
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

ISO exercises and the AMT, 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 →