Guides
Plain-English explainers on the math, rules, and strategies behind every CalcProLabs calculator.
Reverse Mortgages: 7 Things Lenders Don't Want You to Misunderstand
Reverse mortgages (HECMs) have a complicated reputation. Here are the seven realities seniors should know before signing.
Amazon FBA Pricing: Hit Your Real Margins, Not the Dashboard Ones
Amazon's built-in profit estimates miss several costs. Here's the full math you need to price products that actually make money.
When to Refinance Your Mortgage (and When Not To)
The "rate dropped 0.5%" rule is incomplete. The real test: do you stay long enough to recoup the closing costs?
Cap Rate vs. Cash on Cash: Which Metric Should You Trust?
The two most-cited real estate investment metrics measure different things. Use both — and know which one matters when.
Roth vs. Traditional IRA: Which Wins for You?
A decision framework, not a one-size-fits-all answer. When Roth wins, when Traditional wins, and the situations where the answer flips.
PMI Explained: When You Pay It, How Much, and How to Cancel
Private mortgage insurance costs hundreds per month. Here is exactly when lenders require it, what determines the cost, and how to get rid of it ASAP.
S-Corp Reasonable Salary: The IRS Rules in Plain English
How the IRS decides what 'reasonable compensation' means for S-Corp owners, the factors they audit on, and how to defend your number.
The HSA Triple Tax Advantage Explained
How the only triple-tax-advantaged account in the US tax code works, who qualifies, and how to use it as a stealth retirement vehicle.
Workers' Comp Settlement Guide: What to Expect by State
Understand how workers' compensation settlements are calculated, what factors drive value, and when to accept or negotiate.
How to Calculate Compound Interest (With Examples)
Learn the compound interest formula, see worked examples for monthly and daily compounding, and understand why time matters more than rate.
What these guides are for
A calculator answers a question you already know how to ask. These guides are for the stage before that — working out which question applies to your situation, and what the answer will mean once you have it.
Each one is written to be read start to finish rather than skimmed for a number, and each links to the calculators that do the arithmetic. Figures that change annually are stated with the year and the authority they came from, so you can tell at a glance whether a guide has gone stale.
None of this is personalised advice. It is the reasoning behind the numbers, which is the part that transfers to your own circumstances.
How they are written
Every figure in these guides is computed rather than estimated. When a guide says a one percent fee costs $186,876 on $100,000 over thirty years, that number was calculated, not rounded to something that sounded plausible. The same applies to break-even months, effective tax rates and settlement ranges. Where a figure could not be verified against an authoritative source, it is left out rather than approximated.
Tax and benefit limits carry the authority and year they came from — IRS notices and revenue procedures, Social Security Administration figures, state agency schedules. These change annually and on different cycles, so a guide that does not say which year it means is a guide you cannot check. Naming the source is also how a stale number becomes visible rather than silently wrong.
There are no invented experts here. The site does not attribute content to fictional credentialled reviewers, which is a common practice in this category and one that makes every other claim on a page harder to trust. Where something requires professional judgment — a tax election, a settlement, a medical decision — the guide says so and stops.
Where guides end and advice begins
A guide can tell you how a formula behaves, which variable dominates, and where the common mistakes are. It cannot know your bracket, your medical history, your state's case law or your tolerance for a bad outcome, and those are frequently what decides the answer.
The practical division: use these to understand the mechanism and to arrive at a professional conversation with better questions. Anything with a deadline, an irreversible election, or a number large enough that being wrong would hurt is worth paying someone to check.