Personal finance library

Guides and calculators first. The life sim is optional.

WhatIfInLearning is a classroom for money decisions: emergency funds, debt math, housing, retirement order of operations, and PayPal-gated playbooks. Run the numbers before you decide. Written by Thomas Sanders — educational, not advice.

Browse guides Open calculators Premium via PayPal

Open enrollment

HSA vs FSA for 2027

A general health FSA blocks the HSA. 2027 caps $4,500 / $9,000 plus $1,000 at 55 (Rev. Proc. 2026-24). HDHP tests: deductible at least $1,750 / $3,500, OOP at most $8,700 / $17,400. Run last year’s billed charges, not last year’s premiums. 2027 FSA cap is not out yet.

HSA vs FSA guide Open the calculator Enrollment sequence

1099 / Schedule C: Q3 2026 estimated tax is still due September 15 — SE tax primer · calculator.

Learn

30+ free guides

SEO-titled explainers with FAQ schema, 2026 limits, and links into the tools.

Tools

Standalone calculators

Roth vs traditional, savings goal, student loan, inflation, paycheck, FIRE, PITI — each on its own URL.

PayPal

Premium playbooks

$4.99 unlocks articles. $9.99 All Access is the playbook wall. 529 vs taxable is free.

What are you deciding?

Six doors, not a changelog. Pick the next money decision. Hit / with a blank query for these doors plus this week’s seasonal (open enrollment through October; W-4 from January).

Housing

Buy, rent, tap equity

DTI, PITI, extra vs invest, rate-and-term break-even, HELOC vs cash-out.

Retirement

401(k), IRA, Roth

Rule of 55, conversions, RMDs, 62 vs 70 claiming, backdoor, titles vs will.

Debt

Cards, students, cars

IDR vs refinance, 0% transfers, avalanche vs snowball.

Paycheck

Take-home & W-4

2026 brackets, FICA, extra withholding.

Cash

Park cash, then pick a wrapper

Emergency fund, HYSA vs CDs, I-bonds vs T-bills, inflation.

Taxes

1099, HSA, capital gains

Quarterlies, open enrollment, 0/15/20 stack, wash sales.

New this week

Taxes

2026 brackets, not a raise trap

$80,000 single wages, standard deduction $16,100, taxable $63,900, federal income tax $8,770. Marginal 22%. 22% of the whole pile would be $14,058. A $1,000 raise across $50,400 costs $180 of income tax, not a pay cut. 8 FAQ. No new calculator.

Retirement

FIRE number, then the 2026 fine print

$52,000 at 4% is $1,300,000. The calculator’s 3.3% line is $1,575,758. A single filer who needs $52,000 after federal tax from a traditional IRA withdraws about $56,614. 8 FAQ. The thin withdrawal wall now refreshes to sequence of returns.

PayPal

Finish the 0% window on purpose

12-step: one card pull, fee inside the balance, autopay that clears a true 0% promo. $6,400 at 21.9% costs about $1,782 over 28 months at $300; a 3% fee makes $6,592, and $440 clears it in 15 months.

PayPal

Move the sleeve. Do not tidy a ticker.

12-step asset location: inventory, new 401(k) money buys bonds first, specific-ID, do not cross NIIT or IRMAA. $80k bond sleeve example saves $907/year; $2,400 gain is worth selling, $18,000 is not.

Taxes

Asset-location tax-drag calculator

Free. Hash + bars. $80k / 4.2% / 32% ordinary: bond drag $1,075 vs stock-index $168. Saved $907/year, $9,072 over 10. NIIT toggle $992.

PayPal

Leave the 401(k). 72(t) is the other door.

12-step rule of 55: calendar-year test, inbound old plans, do not roll to an IRA, $48k draw example penalty $0 vs $4,800 if you rolled first. 72(t) amort at 5% floor ≈ $30,956 locked five years.

Retirement

Rule of 55 primer

Leave in the year you turn 55 and that employer’s 401(k) skips the 10%. IRAs do not qualify. Numbers page is the 401(k) rollover calculator.

Estate

TOD, POD, and 401(k) vs a will

A will does not move a 401(k). ERISA spouse default, SECURE 10-year, 2026 $15M exclusion. 8 FAQ. Titles file, not an estate-tax file.

PayPal

One-afternoon titles audit

12-step: screenshot, ERISA spouse waiver, IRA contingents, TOD/POD, life/HSA/529, life-event calendar.

Debt

Avalanche vs snowball calculator

Free. Hash + bars. Defaults $2k at 6%, $5k at 24%, $8k at 18%, extra $250: avalanche 38 months / $4,150 interest vs snowball 42 / $5,104. Saves about $954 and 4 months.

Optional

Tip tools index

Find the free calculators that carry an optional classroom tip. Chip rail under the nav on Home, Calculators, and every /tools page.

Family

529 vs taxable calculator

Free. Hash + bars. $8k + $250/mo / 12y / 7% example: 529 $74,660 vs taxable after 15% $70,061. Advantage $4,599. Gift-tax flag $19,000.

Family

529 vs brokerage 2026

Gift exclusion $19,000, superfund $95,000, K-12 $20,000 (IRS Topic 313). Grandparent FAFSA lag is dead. 8 FAQ.

Last run

Social Security claiming calculator

Free. Hash + bars. $2,000 PIA, FRA 67: 62 = $1,400/mo, 70 = $2,480/mo. Break-even 62 vs FRA age 78y 8m; FRA vs 70 age 82y 6m.

Retirement

62 vs FRA vs 70 in 2026

Born 1960+: FRA 67. 62 is 70% of PIA; 70 is 124%. Earnings test $24,480 / $65,160 (labeled SSA).

Last run

Capital gains tax calculator

Free. Hash + bars. Single, $80k proceeds / $20k basis / $40k other taxable: $9,450 at 0% + $50,550 at 15% = $7,583 federal. Short-term would be $12,160.

Taxes

Short-term vs long-term 2026

0% to $49,450 single / $98,900 MFJ. Ordinary fills first. NIIT 3.8% MAGI floors are not indexed.

Last run

Refinance break-even calculator

Free. Hash + bars. $320k / 6.80% → 5.90% / match 27 years / $6,500: P&I $2,159 → $1,977, recoup 35.6 months.

Housing

Months to recoup closing costs

Rate-and-term only. 30-year reset can fake a faster recoup. 6.76% PMMS is an average, not your lock.

Last run

Extra vs invest calculator

All Access. Hash + bars. $300k / 7% / extra $500: 190 months, interest saved $139,558, 10-year extra equity ties $86,542 invested.

PayPal

3% keep-the-loan vs 7% extra

12-step: after-tax coupon, PMI to 80%, do not cash-out the cheap first lien.

Housing

Refi vs extra principal

Extra is a refinance you already own. Type your coupon — 6.76% PMMS is an average.

Last week

IRMAA two-year MAGI lookback

2026 premiums use 2024 MAGI. First cliff $109k / $218k. $1,000 over can cost $1,148/year.

Medicare

IRMAA MAGI room calculator

CMS 2026 table as a stand-in. Filing status, extra MAGI, enrollees, shareable URL.

Open enrollment

HSA vs FSA for 2027

A general FSA blocks the HSA. $4,500 / $9,000. HDHP tests in Rev. Proc. 2026-24. Run last year’s billed charges.

Run the numbers

Family

529 vs taxable

Retirement

Social Security

Retirement

RMD

Medicare

IRMAA MAGI

Retirement

Roth conversion

Retirement

IRA / SEP deadline

Cash

I bonds vs T-bills

Taxes

Capital gains

Taxes

HSA vs FSA

Retirement

Mega backdoor Roth

Housing

HELOC vs cash-out

Housing

Refi break-even

Housing

Extra vs invest

Taxes

Self-employed / 1099

Housing

50 states / COL

Income

Freelance rate

Retirement

Backdoor Roth

Housing

Mortgage PITI

Housing

Debt-to-income

Income

Paycheck 2026

Debt

Balance transfer

Retirement

401(k) rollover

Retirement

Roth vs traditional

Saving

Savings goal

Debt

IDR vs refinance

Cash

Inflation power

Cash

Emergency fund

Debt

Avalanche vs snowball

All

Calculator hub

Account

Premium that survives a new phone

PayPal still unlocks this browser immediately. Add an email so a hashed member list can restore you later. Free newsletter uses the same Formspree inbox — no paid mail tool.

Account / restore

Optional sandbox

Worth Adventure lives on its own page

The year-by-year life sim is not the homepage. Use it after a guide if you want to stress-test choices. Markets are stylized.

Open Worth Adventure

Classroom extras: retirement order of operations · mortgage PITI · car cost. Worth Adventure is optional. This classroom is not a game store.

Written by Thomas Sanders. Not financial, tax, or legal advice — disclaimer. Premium is stored on this device after PayPal and restored by email at /account. Hit / to search the library.