Guides

Half a payment every two weeks is 13 payments a year. On a $400,000, 30-year loan at 6.5% that cuts 5 years 10 months and $116,342 of interest, fees or not.

Years cut and interest saved on a $400,000, 30-year mortgage at 6.5% with an extra $100, $250 or $500 a month, plus one lump sum paid early or late.

The same house and the same extra $400 a month at a 3% and a 7% mortgage rate: the market return at which prepaying and investing come out level.

What an owner pays that builds no equity, set against rent, in years 1 and 10 of DecisionSheet's rent vs. buy model, plus the growth the upfront cash gives up.

When a buyer's net worth overtakes a renter's in DecisionSheet's rent vs. buy model, and how the five-year rule of thumb holds up against it.

A 4% inflation-adjusted withdrawal over 30, 40 and 50 years in 1,000 simulated markets: how often it lasts, and what the median and 10th percentile leave.

Spending $60,000 a year and 30 years old: the portfolio that retires you at 45 at 4%, 3.5% and 3.25%, the saving each needs, and how often it lasts to 95.

The same portfolio under three withdrawal rules for 40 years: how often each lasts, what each leaves, and what the guardrails rule cuts to get there.

The retirement tax rate at which Roth and traditional contributions end level, and why a taxable account for the tax savings pulls it below today's rate.

The same yearly contribution from a low bracket early on and from a high bracket at peak earnings: how the break-even retirement tax rate moves, and why.

Two 36-month leases against one 60-month loan on a $42,000 car: which costs less cash, which ends with more wealth, and which input flips the answer.

One credit card, a fixed minimum payment, and what a fixed extra amount each month does to the months and the interest, run through the calculator.

Avalanche vs. snowball on four debts with the same budget: the exact interest and months each costs, and why the gap can shrink to zero.

The 1099 revenue and hourly rate that match a $75k, $100k or $150k W-2 offer after self-employment tax, expenses, health premiums and the QBI deduction.

How self-employment tax and income tax are built for one 1099 contractor, line by line, at three levels of revenue under 2026 federal rules.

What contributing the HSA maximum every year grows to over 10, 20 and 30 years if it is invested, and why payroll deduction beats writing a check.

Compare a high-deductible plan with an HSA against a PPO in a light, average and bad medical year, on two offers whose answers come out opposite.

How the length of a dollar-cost averaging plan changes the gap with investing $60,000 at once, on a rising and a falling path, compared after 3 years.

Investing $60,000 at once vs. over 12 months, on four fixed market paths: which ends ahead after 3 years, and what the yield on waiting cash does to it.

Lifetime Social Security totals for claims at 62, 67 and 70 by age reached: which claim has paid the most, and how far behind or ahead delaying can end up.

When a later Social Security claim catches up with an earlier one, in plain dollars and in present value, and why the discount rate moves the age.

Months cut and interest saved on a $30,000, 10-year student loan at 6.52% with $50, $100 or $200 a month extra, and what the deduction, rate and term change.

A $30,000, 10-year student loan at 4%, 6.52% and 8.07% with $300 a month to spare: when prepaying beats investing, after the interest deduction and the match.

A $4,000 lender credit for a 7.25% rate instead of 7%: worth taking if the loan ends within about four years, and an expensive way to borrow if it lasts ten.

Two points to cut a $400,000 loan from 7% to 6.5%: the cost ÷ savings rule of thumb, the interest break-even, and the break-even once the cash could earn 4%.

A $400,000 loan at 6.9% over 30 years or 6.2% over 15, with the 30-year borrower investing the $784 gap: who is ahead at 4%, 8% and 10%, and the tie return.

A refinance from 7.75% to 7.03% with $8,000 of closing costs, worked month by month: the real break-even, what resetting to 30 years costs, and how to avoid it.

One $350,000 refinance three ways: $8,000 in cash for 6.5%, $8,000 added to the loan, or no closing costs for 6.875%. Which wins depends on how long you stay.

A $350,000 balance at 7% with 27 years left, refinanced into a 15-year at 6.25% for $6,000: the payment jumps $594, interest falls by half, and the break-even.

A $300,000 loan at 7.5% refinanced for 0.5%, 1% or 1.5% less with 2% closing costs: each cut's real break-even, and the 30-year reset that sinks a half point.

In 2026 the dependent care FSA limit is $7,500 and the care credit starts at 50%. Four households show which saves more, and why care costs decide it.

From 2026, non-itemizers deduct up to $2,000 of gifts and itemizers lose 0.5% of AGI. Five households show when bunching gifts into one year still wins.

2026 401(k) limits: $24,500, an $8,000 catch-up or $11,250 at 60–63, and Roth-only catch-ups over $150,000 of 2025 wages. What each paycheck must defer.

The Social Security wage base resets, withholding tables change, open enrollment kicks in: a December and a January pay stub compared line by line.

The 2026 federal tax on a Roth conversion for five households: the Social Security tax torpedo, the senior deduction phase-out and how much fills each bracket.

How to figure a 2026 required minimum distribution from the IRS Uniform Lifetime Table, when it is due, what it adds to your tax, and how a QCD changes it.

Why an old rollover IRA makes most of a 2026 backdoor Roth conversion taxable, Form 8606 line by line, and the December 31 fix that makes it tax-free.

Three PG&E rate plans priced at the current tariff rates for a heat pump home, an EV owner and a small apartment, with every bill worked out in a table.