Here's a Decision
Decision Guides
Straight answers to the decisions people get stuck on. Each guide ends with a free tool that runs your own numbers.
Should I Repair or Replace My AC? (2026 Cost Guide)
Repair or replace your AC? The $5,000 rule, the 50% rule, and real 2026 costs, plus a free calculator that runs your own numbers.
How Much Does It Cost to Replace an HVAC System in 2026?
Real 2026 HVAC replacement costs by system type, what drives the price, and how to tell if a new system is worth it for your home.
Should I Fix My Car or Buy a New One?
How to decide whether to repair your car or replace it, using the repair-to-value rule plus the factors that actually matter.
Is It Worth Fixing a Car With 150,000 Miles?
High mileage does not automatically mean replace. Here is how to decide whether a repair on a high-mileage car is worth it.
Rent vs Buy: How Long Do You Have to Stay to Break Even?
Buying only beats renting if you stay long enough to recoup closing costs. Here is how the break-even math actually works.
Should I Pay Off Debt or Invest?
The simple rule for choosing between paying down debt and investing, why your interest rate decides it, and what comes first.
Should I Start a Business or Keep My Job?
How to tell if now is the right time to start a business, using runway, market validation, and the risks people underestimate.
Should I Pay Off My Mortgage Early or Invest?
Paying off your mortgage early is a guaranteed return equal to your rate. Investing is an expected one. Here is how to decide, plus a free calculator.
Is It Worth Repairing a 15-Year-Old AC?
At 15 years an AC is near the end of its life. Here is how the $5,000 rule and the 50 percent rule decide repair versus replace, plus a free calculator.
Should I Pay Off Student Loans or Invest?
Your loan rate versus your expected return decides it, but student loans have rules other debt does not. Here is how to choose, plus a free calculator.
Is It Cheaper to Rent or Buy in 2026?
Whether buying beats renting in 2026 depends on how long you stay, the price-to-rent ratio, and the full cost of owning. Here is the math, plus a free calculator.
Is It Worth Fixing a Transmission?
A transmission repair can cost more than the car is worth. Here is how the repair-to-value rule decides whether to fix it or replace the car, plus a free calculator.
How Much Runway Do You Need to Quit Your Job?
Runway is how many months you can cover expenses without income. Here is how much you actually need before quitting to start a business, plus a free calculator.