That's 55% of total payments.
LNS-01 · Mortgage payment
What will this
house actually
cost me,
monthly?
Enter a price, a deposit, a rate and a term. We'll tell you the monthly payment, how much of it is yours and how much is the bank's, and - quietly - the total you'll have paid by the last month.
LiveMonthly payment
LNS-01 · v3.2
Monthly payment
$1,216/ mo
Total paid $497,776 · Interest $197,776
§ 01
Of every payment, one part
is yours, one is the bank's.
The principal side grows over time; the interest side shrinks. In year one, most of what you pay is interest. In the last year, almost none of it is.
Or about kr 54,938 per year.
This is the amount that reduces the loan balance after the first payment.
Interest is nearly half of the total scheduled cost in this example.
§ 02
The first six months, and a
handful of milestones.
Not the full ledger - that is 360 rows long. Open the full schedule if you want every line.
| # | Month | Interest | Principal | Balance |
|---|---|---|---|---|
| 001 | Month 1 | kr 7,500 | kr 2,634 | kr 1,997,366 |
| 002 | Month 2 | kr 7,490 | kr 2,644 | kr 1,994,723 |
| 003 | Month 3 | kr 7,480 | kr 2,653 | kr 1,992,069 |
| 004 | Month 4 | kr 7,470 | kr 2,663 | kr 1,989,406 |
| 005 | Month 5 | kr 7,460 | kr 2,673 | kr 1,986,732 |
| 006 | Month 6 | kr 7,450 | kr 2,683 | kr 1,984,049 |
| 012 | Month 12 | kr 7,389 | kr 2,744 | kr 1,967,735 |
| 060 | Month 60 | kr 6,849 | kr 3,285 | kr 1,823,158 |
| 120 | Month 120 | kr 6,022 | kr 4,112 | kr 1,601,789 |
| 240 | Month 240 | kr 3,691 | kr 6,443 | kr 977,794 |
| 360 | Month 360 | kr 38 | kr 10,096 | kr 0 |
Show all 360 rows →
§ 03
The formula,
worked through.
Every calculator on Wisecalcs ends this way. No black box, no "trust us". You should be able to check our homework on paper.
M = P · r(1 + r)^n / ((1 + r)^n - 1)
MMonthly principal-and-interest paymentPLoan principalrMonthly interest rate, annual rate divided by 12nTotal number of monthly paymentsFor your numbers: principal $300,000, monthly rate 0.3750%, across 360 months. Plug those in and the monthly payment comes out to $1,520.06. You can verify with a spreadsheet: the function is PMT().
§ 04
What a mortgage payment
is actually telling you.
A short read for the curious - what the number means, why it shifts, and what to watch for before you sign.
What this mortgage calculator estimates
This calculator estimates the principal-and-interest part of a fixed-rate mortgage payment. It uses the loan amount, annual interest rate, and term to calculate the scheduled monthly payment.
It does not automatically include property taxes, homeowners insurance, private mortgage insurance, HOA dues, closing costs, or local fees. Those costs matter in a real budget, so treat the result as the loan payment rather than the full cost of owning a home.
Why early payments feel slow
Mortgage amortization front-loads interest. The payment stays the same, but the split changes. In month one of the default example, interest is larger than principal. Years later, the balance is lower, so less interest accrues and more of the same payment reduces the loan.
That is why small rate changes can move the monthly payment and lifetime interest by a surprising amount. A lower rate reduces every interest calculation across hundreds of payments.
How to use the calculator well
Run at least three scenarios: your expected loan, a higher-rate version, and a shorter-term version. The higher-rate scenario gives you a stress test. The shorter-term scenario shows what it costs monthly to save interest over the life of the loan.
If you are comparing actual offers, also compare APR, points, fees, prepayment rules, and whether taxes and insurance are escrowed. The calculator keeps the math clean, but the mortgage decision includes more than the formula.
§ 05
Experience, expertise,
and the working out.
We publish who built the calculator, the formulas behind it, the sources we relied on, and the date it was last reviewed - so you can decide for yourself whether to trust the number.
— Reviewed by
W
The Wisecalcs team
Every calculator on Wisecalcs is built, reviewed, and maintained by the team behind the site. We cross-check the maths against authoritative sources, run the formulas against worked examples, and update each tool when the underlying rules change. We are independent of any lender, broker, or insurer - nothing on this page is a paid recommendation.
— Methodology
How this number is calculated
The payment is calculated with the standard fixed-rate amortization equation using monthly interest and a fixed number of scheduled payments. Displayed pilot metrics use the default $300,000, 4.5%, 30-year scenario.
- Privacy
- Local inputs
- Runtime
- Deterministic
- Precision
- Whole currency units
- Scope
- P&I only
— Sources & references
Where the rules come from
Consumer finance and lending math convention
Used here for fixed-rate principal-and-interest estimates.
WiseCalcs editorial note
Specific lender terms should be checked against official loan disclosures.
— Editorial standards
How we keep this honest
User-provided assumptions. The calculator does not claim a current market rate. Users enter the rate they want to test.
Transparent math. The payment equation, variables, and worked example are shown on the page.
First published2026-04-26
Last reviewed2026-04-26
Versionv3.2
Next review2027-04-26
This calculator is for educational estimates only. It does not approve loans, quote lender terms, or replace advice from a qualified mortgage professional.