Calculators that show the math.
Every tool here is free, needs no login, and is built to make the math visible — so you understand the answer, not just read it. New calculators are added regularly.
Open one and start.
Compound Interest
See how a starting amount and a monthly habit grow over time — and how much of the total is growth you never had to earn.
Mortgage Payment
Your real monthly payment — principal, interest, taxes, insurance, and PMI — plus what extra payments would save you.
Retirement Projection
How much you'll have at retirement, based on your age, savings, and contributions. Currently featured on the home page.
Cost of Living
Compare U.S. cities on an interactive map. Click any metro and see what your salary needs to be in another city for the same lifestyle.
Mortgage Rate Comparison
Today's rates from eight major lenders, side by side, with an embedded payment calculator and editorial verdicts.
Being built next — you pick.
Each of these is queued. Vote for what you'd use first, and the most-wanted one gets built next.
Each vote opens your mail client with a one-line note already drafted. Send it and your vote arrives in my inbox — I read every one.