Personal finance calculators.
The math, not the funnel.

Why these eleven

Personal finance has a small number of decisions that move the needle, and a large number of distractions. The calculators above cover the decisions, organized by when most people face them:

• Housing — the biggest line item on most household balance sheets. Mortgage and HELOC do the loan math; Affordability bounds the search before you fall in love with a listing; Rent vs. Buy compares the two paths over realistic holding periods; Refinance figures out whether rate-and-term refi is worth the closing costs.
• Debt & credit — auto loans, personal loans, credit cards, and debt-payoff sequencing. The hidden math here is almost always APR vs. interest rate, the way trade-in tax credits work, and whether avalanche or snowball gets you to the finish line faster (the calculator shows you both).
• Student loans & wealth — federal IDR plans (SAVE / PAYE / IBR) have specific formulas tied to the HHS poverty guidelines; the calculator runs them all and shows forgiveness clocks. The investment calculator answers the opportunity-cost question buyers actually need: what does this down payment become if I invest it instead?

If you came here from a search for "how much house can I afford" or "how to pay off credit cards," start with the relevant tool above. If you're doing your own financial planning, the order on this page is usually the right order to think about them in: housing first, then high-interest debt, then student loans, then wealth-building.

The deeper math

If you want to understand the formulas the same way a credit analyst does, the underwriting calculators apply the commercial-finance versions of the same concepts: DTI becomes Global DSCR, coverage becomes FCCR, and the working-capital question becomes the cash conversion cycle. The methodology page documents the formula and primary source for every calculator on the site.

Background reading

• First-Time Home Buyer Guide — closing costs, LTV thresholds, and why 5% down usually beats 3%.
• PMI Removal Guide — automatic, requested, and final cancellation per the Homeowners Protection Act.
• Refinance Break-Even — the exact month closing costs are recovered.
• Debt Consolidation Without Getting Trapped — when consolidation actually saves money.
• SAVE vs. PAYE vs. IBR — which IDR plan minimizes total cost.
• Upside-Down Auto Loan — what to do when you owe more than the car is worth.
• Financial glossary — APR, PMI, PITI, LTV, DTI, and the rest, defined cleanly.

Embed any of these

Every calculator has a permissive iframe embed — drop one into a personal-finance blog, a financial-literacy course, or a credit-counseling resource site. No tracking, no branding requirement. See the embed library for the iframe snippets.