Explainers behind the calculators. Each one should end in a number you can run yourself — brackets after the standard deduction, a mortgage PITI split, a 401(k) match formula, or a Roth versus traditional compare on the same paycheck dollars. Guides are written and updated by Greg at Finance Maxx; they are educational, not advice.
Rev. Proc. 2026-24 sets 2027 HSA limits at $4,500 self-only and $9,000 family (+$100 / +$250 vs 2026). HDHP floors, OOP caps, catch-up, and open-enrollment notes for fall 2026 plan elections.
Announcement 2026-11 raised the business mileage rate to 76 cents from July 1, 2026. Use 72.5¢ for H1 miles and 76¢ for H2. Medical/moving 20.5¢ then 23.5¢. Charity stays 14¢.
IRS Notice 2026-60 rates effective Oct 1, 2026. Transportation M&IE $80/$86, high-low $329/$230, incidental $5, transition rules for late 2026, and locality list changes.
How employer contributions to Trump accounts work under IRC section 128. The $2,500 exclusion per employee, W-2 box 12 code TA, FICA still applies, and how the $5,000 account limit interacts.
How the temporary enhanced deduction for seniors works. The $6,000 per person cap, MAGI phaseout, Schedule 1-A Part V, and how it stacks with the extra standard deduction for age 65+.
How the temporary deduction for qualified tips works. The $25,000 cap, MAGI phaseout, tipped occupations list, W-2 box 12 code TP, and why FICA still applies.
How the temporary deduction for FLSA overtime premium works. The $12,500 cap, MAGI phaseout, W-2 box 12 code TT, and why only the “half” of time-and-a-half counts.
How the temporary deduction for interest on a new US-assembled car loan works. The $10,000 cap, first-lien and personal-use tests, negative equity, and why the tax savings are smaller than the interest you paid.
Same extra dollar each month — pay the loan down or invest it — and compare net worth at a horizon, including leftover debt.
How a withdrawal-rate target turns annual spend into a nest-egg goal, and why a constant real return is only a planning shortcut.
Self-only vs family HDHP limits, the age-55 catch-up, and why employer deposits count toward the same IRS ceiling.
How SALT, mortgage interest, and charity stack against this year’s standard deduction — and when itemizing actually cuts federal tax.
Why the fair compare is tax now versus tax later on the same pre-tax contribution, not two equal account deposits.
How a paycheck is split into Social Security, Medicare, federal income tax, and optional 401(k) deferrals — and what this model leaves out.
What Trump Accounts are for kids in 2026, who gets the $1,000 pilot seed, the $5,000 annual contribution limit, tax treatment, and how compounding can grow balances by age 18.
Elective deferrals, employer match formulas, SIMPLE IRA, IRS limits, and Roth IRA MAGI phase-outs in plain language.
Needs, wants, and savings — a flexible split for take-home pay, not a hard rule.
How big a cash buffer to target and how long contributions take to get there.
Why the same dollars may buy less later — and how to read a simple future inflation projection.
When a lower rate is worth the closing costs — cash-flow break-even vs total interest.
Principal, interest, taxes, insurance, and PMI — what goes into a monthly housing payment and how fixed-rate amortization works.
Housing and total DTI rules of thumb, why max home price is not a pre-approval, and how down payment, debts, APR, and taxes change the estimate.
Assets minus debt, a simple goal bar, and why a lightweight snapshot is often enough to stay honest about progress.
Why paying more than the minimum shortens payoff time, how interest is calculated each month, and when a payment is too low to ever catch up.
How a loan payment calculator estimates monthly payment from principal, APR, and term — and why total interest grows with longer terms.
Why time and recurring contributions matter more than chasing the perfect interest rate — for savings, bonds, stocks, and more.
Federal tax brackets explained — they apply after the standard deduction. Marginal vs effective rates, and why a higher bracket does not re-tax all your income.