Loan & Mortgage Calculator

Monthly payment formula: M = P × [r(1+r)ⁿ] ÷ [(1+r)ⁿ − 1], where P = principal, r = monthly interest rate (annual rate ÷ 12), n = total number of payments.

Worked example — $300,000 mortgage at 6.5% for 30 years:

• Monthly rate r = 6.5% ÷ 12 = 0.5417%
• n = 30 × 12 = 360 payments
• Monthly payment = $1,896
• Total paid = $682,560 — total interest = $382,560

Early in a loan, most of each payment covers interest. For the example above, month 1 allocates roughly $1,625 to interest and only $271 to principal. By month 180 (year 15), the split is roughly equal.

Extra monthly payments reduce the principal faster, shortening the loan term and cutting total interest significantly. Adding $200/month to the example above saves over $60,000 in interest and pays off the loan 6 years early.

Comparing offers. Two quotes on the same house rarely differ only in rate — the cheaper rate is usually bought with points paid at closing. The comparison tab tracks each offer's running total from signing onwards and reports the month the cheaper one pulls ahead for good. On the $300,000 example, dropping 6.5% to 6.0% for $6,000 of points saves $97.55 a month, so the points are repaid in month 62 — a little over five years. Move before then and the points were a loss.

The same figure answers a 15-year against a 30-year, where nothing is paid at signing at all. The 15-year costs more every month, so it stays behind on cumulative outlay well past its own payoff: at 5.75% against a 30-year at 6.5%, it is repaid in year 15 but does not overtake until month 237.

Link to this tool with values filled in

Everything after the # stays in your browser — it is never sent to a server — so a link like this opens the tool ready to go without the values travelling anywhere but the address bar:

https://crunchify.net/tools/loan-calculator#principal=350000&rate=6.5&term=30

Join the settings with &, and percent-encode each value so that spaces, newlines and any #, &, = or % inside one do not break the link. Leave a setting out to accept its default. If a setting is not recognised, the page says so rather than quietly ignoring it.

• principal (also amount, loan, p or q) — a whole number from 1 to 1000000000000, required. The amount borrowed, in dollars.
• rate (also apr, interest or interestrate) — a whole number from 0 to 100, required. Annual interest rate as a percentage, for example 6.5.
• term (also years, length or duration) — a whole number from 1 to 100, required. How long the loan runs, in the unit named below.
• termunit (also unit or termin) — years or months, defaults to years. Whether the term above is in years or months.
• extra (also extrapayment or additional) — a number, defaults to 0. Extra paid against the principal each month, if any.
• inflation (also inflationrate) — a whole number from 0 to 100. Annual inflation as a percentage. Omit to leave the inflation-adjusted figures off.
• compare (also comparison or sidebyside) — true or false, defaults to false. Open the side-by-side comparison of two or three offers instead of the single-loan view.
• upfront (also points, closingcosts or fees) — a number, defaults to 0. Points and closing costs paid at signing for this offer, in dollars. What the break-even is measured against; with none on either offer there is nothing to recover.
• rate2 (also apr2 or interest2) — a whole number from 0 to 100. Annual interest rate of the second offer, as a percentage. Setting any second-offer field opens the comparison.
• term2 (also years2 or length2) — a whole number from 1 to 100. How long the second offer runs, in the unit named below.
• termunit2 (also unit2 or termin2) — years or months. Whether the second offer’s term is in years or months. Defaults to years.
• extra2 (also extrapayment2 or additional2) — a number. Extra paid against the second offer’s principal each month, if any.
• upfront2 (also points2, closingcosts2 or fees2) — a number. Points and closing costs paid at signing for the second offer, in dollars.
• rate3 (also apr3 or interest3) — a whole number from 0 to 100. Annual interest rate of a third offer. Setting any of the third offer’s fields adds it to the comparison; omitting them all compares two.
• term3 (also years3 or length3) — a whole number from 1 to 100. How long the third offer runs, in the unit named below.
• termunit3 (also unit3 or termin3) — years or months. Whether the third offer’s term is in years or months. Defaults to years.
• extra3 (also extrapayment3 or additional3) — a number. Extra paid against the third offer’s principal each month, if any.
• upfront3 (also points3, closingcosts3 or fees3) — a number. Points and closing costs paid at signing for the third offer, in dollars.

The tool reads these on arrival but never writes them back, so what you type here stays out of your browser history.