Comparison
| Rate | Monthly payment | Total interest | Interest diff vs. first |
|---|
"Interest diff vs. first" compares each rate against the first rate you entered. A positive number means you would pay that much more in total interest over the full term.
What a half-point is really worth
Interest rates are usually quoted in tiny fractions — 6.0% versus 6.5% can feel like a rounding error. On a loan, it is anything but. Enter your loan amount and term, then set the first rate to the lower quote and the second to the higher one. The interest diff vs. first column shows the total interest you would avoid by securing the lower rate. On a $300,000, 30-year mortgage, the gap between 6.0% and 6.5% is roughly $35,000 in interest — even though the monthly payment difference is only about $98.
The monthly payment difference looks modest because a 30-year term spreads the cost over 360 payments. That is why lenders love to quote the monthly number: it makes expensive differences feel small. The total-interest figure is where the real cost hides. When you are shopping, compare rates on the same loan amount, term, and points, and always look at total interest — not just the monthly payment.
This tool is generic: it works for mortgages, auto loans, and personal loans alike. Once you have settled on a rate, use the loan calculator for a full amortization breakdown, or check current averages in the rate tables. For a deeper look at the half-point question, start from the mortgage rate desk.