AmortMapWhat a given loan amount actually costs per month, and over its life.

Monthly payment on a $550k mortgage at 4.75%

$550k at 4.75%
$2,869per month
principal and interest only over 30 years — the real bill is $3,276–$4,468
$550k at 4.75% — monthly$2,86930 yr P&I$4,468with escrow$4,27815 yr P&Isolid = principal and interest · shaded = tax, insurance and PMI
Principal & interest, 30 yr$2,869
Realistic total paymentadds property tax, insurance and PMI — the range is mostly state tax$3,276–$4,468
Total interest over 30 yrless than the amount borrowed$482,862
20-year payment$3,554
15-year payment$1,409 more a month, $262,808 less interest$4,278
First payment: interest$2,177
First payment: principalonly 24% of the payment touches the debt$692
Per $1,000 borrowedscales linearly at 4.75% over 30 years$5.22

Notes

  • The quoted payment is not the bill. $2,869 is principal and interest. Property tax, homeowner's insurance and — under 20% down — private mortgage insurance are collected alongside it, and on this loan they add roughly $407 to $1,599 a month.
  • Property tax is the biggest variable and it is geographic. Effective rates run from about 0.3% of value in the lowest states to over 2% in the highest — a factor of six on the same house. That single line moves the monthly bill here by roughly $917, which is more than a full percentage point of interest rate.
  • Where the money goes early on. The first payment is $2,177 interest and $692 principal — 24% of it reduces the debt. The crossover, where principal first exceeds interest within a single payment, arrives around year 15 at this rate. That asymmetry is why an extra payment in year two is worth many times the same payment in year twenty.
  • Fifteen years costs $1,409 more a month and saves $262,808 in interest. Whether that is a good trade depends on what the extra $1,409 would otherwise do — which is a different question from which loan is cheaper.
  • Payment scales linearly with the amount at a fixed rate: $5.22 per $1,000 borrowed at 4.75% over 30 years. That shortcut works for any figure, not just the round ones.

The short answer

A $550k mortgage at 4.75% over 30 years costs $2,869 a month in principal and interest.

The actual bill is closer to $3,276–$4,468, and the gap is made of three things a rate table cannot know.

What the calculator leaves out

Line On this loan
Principal & interest $2,869
Property tax varies six-fold by state
Homeowner's insurance roughly 0.5% of value a year
PMI, if under 20% down roughly 0.6% of the loan a year

Property tax is the biggest variable and it is geographic. Effective rates run from about 0.3% of value in the lowest states to over 2% in the highest. On this loan that single line moves the monthly bill by more than a full percentage point of interest rate would.

PMI disappears at around 20% equity. Tax and insurance do not.

Where the money goes early on

The first payment is $2,177 interest and $692 principal — only 24% of it reduces the debt.

Interest is charged on the outstanding balance, which is largest at the beginning. That asymmetry is why an extra payment made in year two removes far more total interest than the same payment in year twenty, and it is the whole argument for paying early rather than paying more.

Term changes the shape completely

Term Monthly Total interest
30 years $2,869 $482,862
20 years $3,554
15 years $4,278 $220,054

Fifteen years costs $1,409 more a month and saves $262,808 in interest.

Whether that is a good trade depends on what the extra $1,409 would otherwise do. It is a question about your other options, not about which loan is cheaper — the shorter loan is always cheaper.

The shortcut for any other amount

At 4.75% over 30 years, each $1,000 borrowed costs $5.22 a month.

Payment scales linearly with the amount at a fixed rate, so that figure answers any loan size without another calculation.

What actually moves the payment

Rate and term, in that order. A quarter-point of rate is worth more on a large loan than most people expect, and it is the reason shopping more than one lender is the highest-return hour available in the whole process.

Points — paying 1% of the loan up front to lower the rate by roughly a quarter point — pay for themselves in about five years. Whether that is worth it depends on how long the loan will actually be held, and the median is closer to a decade than to thirty years.

Nearby sizes

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