US Tax Suite: 35 Free Personal Finance, Tax, FIRE & Compensation Calculators
High-intent, low-competition US tax tools built with pure client-side math, zero tracking, and authentic IRS Form & statutory IRC citations.
1099 Independent Contractor vs. W-2 Salary Equivalent Calculator (All 50 States)
Calculate your true take-home pay comparison between 1099 self-employment and a W-2 salaried job, accounting for 15.3% SE tax, § 199A QBI deductions, and state tax rules.
S-Corp Reasonable Salary vs. LLC Tax Savings Calculator
Discover the exact profit threshold where electing S-Corporation taxation beats a standard LLC by shielding distributions from 15.3% self-employment taxes.
IRS Quarterly Estimated Tax (Form 1040-ES) Safe Harbor Calculator
Calculate your exact quarterly estimated tax payments and safe harbor thresholds to eliminate IRS underpayment penalties under IRC § 6654.
Mega Backdoor Roth 401(k) After-Tax Contribution Limit Calculator
Maximize your annual after-tax 401(k) contributions up to the IRC § 415(c) limit ($70,000 in 2025) and simulate tax-free compound growth.
Roth IRA Pro-Rata Rule & Backdoor Conversion Tax Calculator (Form 8606)
Calculate the exact taxable portion of your Backdoor Roth IRA conversion when holding pre-tax balances across Traditional, SEP, or SIMPLE IRAs.
RSU (Restricted Stock Unit) Vesting Tax Withholding Gap Calculator
Calculate your true tax liability on vesting RSUs vs. statutory 22% supplemental withholding to avoid a massive April 15 underpayment penalty.
ISO vs. NSO Stock Option AMT (Alternative Minimum Tax) Crossover Calculator
Model your Incentive Stock Option exercises against Form 6251 AMT exemption phaseouts to calculate the exact number of shares you can exercise with $0 AMT.
ESPP (Employee Stock Purchase Plan) Lookback & Qualifying Disposition Calculator
Maximize after-tax proceeds from your Section 423 ESPP by comparing qualifying vs. disqualifying dispositions and avoiding double taxation on Form 8949.
Coast FIRE & Barista FIRE Age Calculator with ACA Subsidy Optimizer
Calculate your Coast FIRE milestone age and simulate Barista FIRE cash flows while optimizing ACA Premium Tax Credits (PTC) to keep health insurance nearly free.
72(t) SEPP (Substantially Equal Periodic Payments) Early Retirement Calculator
Calculate penalty-free early distributions from your Traditional or Roth IRA before age 59½ using all 3 IRS-approved methods under Notice 2022-6.
Social Security Spousal & Early vs. Age 70 Break-Even Age Calculator
Compare claiming Social Security at 62, Full Retirement Age (67), or 70, modeling 8% annual delayed retirement credits and cumulative lifetime crossover points.
IRMAA Medicare Part B & Part D Surcharge Cliff Calculator
Prevent surprise Medicare premium spikes by modeling the 2-year lookback MAGI tiers and avoiding $1 threshold crossings on Roth conversions.
HSA (Health Savings Account) Triple-Tax Advantage vs. PPO Plan Comparison
Compare high-deductible health plans (HDHP) paired with an HSA against traditional PPO plans, factoring in 7.65% FICA exemption and long-term compound growth.
FSA (Flexible Spending Account) 'Use-It-Or-Lose-It' Year-End Spend Planner
Calculate your forfeited FSA dollars and allocate unspent balances toward eligible items before the annual December 31 deadline.
529 College Savings Plan vs. Roth IRA / UTMA Custodial Account Calculator
Compare 529 plans, Roth IRAs, and UTMA accounts for college funding, modeling state tax deductions, FAFSA impact, and SECURE 2.0 $35K Roth rollovers.
FAFSA Student Aid Index (SAI) Parent Asset Impact Estimator
Estimate how savings, brokerage investments, and 529 plans impact your Student Aid Index (SAI) under the Department of Education FAFSA Simplification Act.
PSLF (Public Service Loan Forgiveness) & SAVE/IBR Discretionary Income Calculator
Calculate your monthly income-driven student loan payment and total tax-free forgiveness after 120 qualifying payments under PSLF.
Capital Gains Tax Harvesting (0% Long-Term Bracket) Optimizer
Determine exactly how much long-term stock gain you can realize at 0% federal tax rate, locking in a permanently higher cost basis.
Crypto & Stock Wash-Sale 30-Day Window Calendar & Cost Basis Calculator
Track your 61-day wash-sale window (-30 to +30 days) under IRC § 1091, calculating disallowed losses, cost basis adjustments, and Form 8949 Code 'W' entries.
I-Bond Composite Interest Rate & Optimal Redemption Month Calculator
Calculate your Series I Savings Bond composite interest rate and determine the exact optimal month to redeem to surrender the lowest 3-month interest penalty.
Treasury Bill (T-Bill) vs. Bank CD State-Tax-Adjusted Yield Calculator
Calculate state-tax equivalent yields under 31 U.S.C. § 3124 to discover why a 4.8% T-Bill beats a 5.2% bank CD in high-tax states like CA, NY, and NJ.
Credit Card 0% APR Balance Transfer Fee vs. Personal Loan Payoff Calculator
Compare 3%–5% upfront balance transfer fees against fixed APR personal loans to find your cheapest debt elimination path and avoid post-promo APR traps.
Credit Utilization Ratio & Statement Closing Date Paydown Optimizer
Target the critical 8.9% and 28.9% FICO scoring thresholds and master the AZEO (All Zero Except One) strategy by paying balances before statement closing dates.
Auto Lease Money Factor to APR Converter & Residual Value Negotiator
Convert dealership lease money factors into equivalent APRs (Money Factor × 2,400), spot hidden finance charge markups, and calculate true monthly lease payments.
Used Car Out-the-Door (OTD) Price & State Trade-In Sales Tax Credit Calculator
Calculate your true dealership Out-The-Door price across all 50 states, factoring in state trade-in tax credits, documentation fees, and registration costs.
EV Federal Tax Credit (IRC 30D / 25E) & Home Charger vs. Gas Payback Calculator
Check eligibility for the $7,500 new clean vehicle credit (IRC § 30D) or $4,000 used credit (§ 25E) and calculate fuel payback months vs. gasoline.
Nanny & Household Employee 'Nanny Tax' (Schedule H) Paycheck Calculator
Calculate household employee paycheck withholdings, employer FICA contributions, FUTA, and state unemployment taxes under IRS Schedule H.
Military BAH, BAS & Combat Zone Tax Exclusion Civilian Salary Equivalent Calculator
Convert military compensation into the exact civilian salary needed to match take-home pay, modeling non-taxable BAH, BAS, and state tax exemptions.
Travel Nurse Tax-Free Stipend vs. Taxable Hourly Blended Rate Calculator
Calculate your weekly blended take-home pay, verify permanent tax home compliance under Rev. Rul. 73-529, and benchmark travel nurse packages against staff W-2 jobs.
Waitstaff & Bartender Tip Out, Tip Credit & Effective Hourly Wage Tracker
Track your busser/barback tip outs, verify employer tip credits under the FLSA, and calculate your true effective take-home hourly wage.
Alimony & Child Support State Guideline Estimator (Income Shares Model)
Estimate statutory child support obligations based on combined parental net income, parenting-time overnights, and post-TCJA alimony tax rules.
Lottery Lump Sum (Cash Option) vs. 30-Year Annuity After-Tax Calculator
Compare after-tax cash payouts between the lump sum cash option and 30 graduated annual payments across all 50 states, factoring in 37% federal brackets.
Marriage Tax Penalty vs. Marriage Bonus Calculator (Dual-Earner Optimizer)
Model your joint vs. single filing tax liability to uncover marriage penalties caused by compressed 35%/37% brackets and the $10,000 SALT deduction cap.
Gift Tax Annual Exclusion & Lifetime Estate Exemption Tracker (Form 709)
Track your annual per-donee exclusions ($19,000 in 2025) and unified lifetime estate exemption ($13.99M) to debunk the myth of immediate gift taxes.
US Inflation Purchasing Power & Salary Raise Erosion Calculator
Benchmark your salary raises against official Bureau of Labor Statistics (BLS) CPI-U historical data to calculate your real purchasing power gains or losses.
US Statutory Tax & Compensation Architecture (2025–2026 Framework)
Managing personal finance, taxation, and wealth accumulation in the United States requires reconciling statutory federal mandates under the Internal Revenue Code (Title 26 USC) with disparate state tax structures and annual inflation indexing. Unlike static rulebooks, federal parameters adjust each tax year pursuant to statutory cost-of-living adjustments (COLAs) calculated by the Bureau of Labor Statistics and codified by the IRS in annual revenue procedures.
Key structural pillars governing the 2025 and 2026 tax periods include:
- The FICA Wage Ceiling: Under the Social Security Act, the OASDI maximum taxable wage base rises to $176,100 in 2025 (up from $168,600 in 2024). Earnings above this threshold are exempt from the 6.2% employee and employer Social Security tax, while the 1.45% Medicare tax remains uncapped. High earners also face the 0.9% Additional Medicare Tax on wages exceeding $200,000 (Single) or $250,000 (Married Filing Jointly).
- Section 199A Pass-Through Mechanics: The 20% Qualified Business Income (QBI) deduction enables eligible sole proprietors, single-member LLCs, and S-Corporation shareholders to deduct up to 20% of net qualified business income, subject to taxable income phase-out ranges ($197,300 Single / $394,600 MFJ in 2025) and W-2 wage limitations.
- Defined Contribution Plan Ceilings: IRC § 415(c) establishes the total annual additions limit for 401(k), 403(b), and solo retirement plans at $70,000 for 2025, enabling substantial Mega Backdoor Roth capacity above the standard $23,500 elective salary deferral cap.
- Alternative Minimum Tax (AMT) Thresholds: For equity compensation holders exercising Incentive Stock Options (ISOs), the AMT exemption is $88,100 (Single) and $137,000 (MFJ) in 2025, with phaseouts commencing at $626,350 and $1,252,700 respectively.
Every calculator in this 35-tool platform executes exclusively inside your local browser via sandboxed client-side JavaScript math. Zero salaries, profit figures, investment balances, or personal identifiable information (PII) are ever transmitted to remote web servers, external APIs, or analytics tracking databases.