Learn the reasoning
Practical calculation guides
Detailed explanations for the places where a correct formula can still produce a misleading answer.
Everyday math
Shopping decisions
Small-business pricing and profit
Insurance and family protection
Adult health estimates
2026 federal tax planning
2026 Stock Compensation Taxes: RSUs, ISOs, NSOs, and ESPPs
Identify the award, map income and withholding, preserve regular and AMT basis, reconcile sales, and plan cash from the complete return.
2026 Self-Employed Taxes: Profit, SE Tax, and Payments
Follow the sequence from business records and net profit through Social Security and Medicare tax, income-tax projection, safe harbors, and payment dates.
2026 Tipped Worker Taxes: Records, Forms, and Deduction
Separate tips from service charges, follow employee or business reporting, reconcile the new 2026 form fields, and claim Schedule 1-A only after the records agree.
2026 SALT Deduction and Itemizing
Build a supported personal-tax subtotal, apply the temporary cap and MAGI phasedown, complete Schedule A, and compare deduction paths.
2026 Family Tax Credits: CTC, EITC, and Care Credit
Choose the correct credit path, check each person under the right definition, gather the required records, and understand refundability before combining results.
2026 HSA vs. FSA: Eligibility, Limits, and Plan Choices
Compare complete health plans first, then coordinate HSA eligibility, health FSA design, employer funding, spouse coverage, carryover, Medicare, and account access.
Personal finance foundations
Pay and work decisions
Interest, borrowing, vehicles, and housing
Car Financing: Buy, Lease, Refinance, or Pay Early
Compare out-the-door price, amount financed, APR, lease restrictions, equity, refinance break-even, and extra principal.
Mortgage Planning: Affordability, Ownership, and Refinance
Follow a complete decision path from household budget and cash reserves through renting, buying, amortization, and refinancing.
HELOC vs. Home Equity Loan: Costs, Rates, and Risks
Compare lump-sum and revolving access, fixed and variable rates, draw and repayment phases, CLTV, fees, and collateral risk.
Mortgage Refinance Math: Costs, Terms, and Break-Even
Compare payoff balance, new principal, cash or financed costs, term resets, remaining balances, interest, and economic break-even.
Mortgage Affordability Math: DTI, Cash, and Housing Costs
Understand income, debt, front- and back-end DTI, PITI, HOA, mortgage insurance, closing cash, and personal budget limits.
Rent vs. Buy Math: Costs, Equity, and Opportunity Cost
Compare mortgage amortization, transaction costs, maintenance, appreciation, rent growth, invested differences, and uncertain horizons.
Credit Card Payoff and Debt Consolidation Math
Compare fixed payments, rolled payments, balance transfers, consolidation loans, fees, terms, collateral, and total cost.
APR vs. APY vs. Interest Rate
Learn which rate belongs in savings, loan, and mortgage calculations, and why borrowing and deposit percentages are not interchangeable.
Interest, Compounding, and Loan Payments Explained
Understand simple and compound growth, nominal rates, effective yield, amortized payments, APR, fees, and the assumptions behind projections.
Retirement income and financial independence
2026 Senior Tax Planning: Deductions, Social Security and IRMAA
Build the return in order, keep four deduction concepts separate, and connect taxable benefits, RMDs, gains, payments, and Medicare without reusing the wrong MAGI.
When to Claim Social Security: Break-Even Math and Limits
Use personal SSA estimates while keeping work rules, spouse and survivor benefits, Medicare timing, taxes, and uncertainty outside a simple crossover.
Pension Lump Sum vs. Annuity: A Decision Guide
Compare matched pension offers while preserving survivor terms, COLA, essential income, taxes, rollovers, plan protection, and household risk.
2026 Medicare IRMAA: MAGI, Brackets and SSA-44
Find the two tax-return inputs, choose the correct filing-status table, total per-beneficiary costs, and identify the proper SSA review route.
Debt Payoff, 401(k) Match, and FIRE Planning
Connect amortization, employer matching, contribution limits, real returns, spending targets, withdrawal assumptions, and scenario risk.