Boliglånebetalningkalkulator
Calculate your monthly mortgage payment, total interest, and amortization. Enter loan amount, rate, and term.
Slik bruker du denne kalkulatoren
- Skriv inn Loan Amount (kr)
- Skriv inn Annual Rate (%)
- Skriv inn Term (years)
- Klikk på Beregn-knappen
- Les resultatet som vises under kalkulatoren
How Monthly Mortgage Payments Are Calculated
The monthly mortgage payment formula is:
M = P × [r(1+r)^n] / [(1+r)^n − 1]
Where:
- M = Monthly payment
- P = Principal loan amount
- r = Monthly interest rate (annual rate ÷ 12)
- n = Total number of payments (years × 12)
Example: kr3,150,000 loan at 6.5% for 30 years:
r = 0.065 / 12 = 0.005417, n = 360
M = 300,000 × [0.005417 × (1.005417)^360] / [(1.005417)^360 − 1] = kr19,908/month
Over the full 30 years, total payments = kr19,908 × 360 = kr7,166,880. You paid kr4,016,880 in interest on top of the kr3,150,000 principal — more than the home's original price again in interest.
15-Year vs 30-Year Mortgage Comparison
The choice between a 15-year and 30-year mortgage is one of the most significant financial decisions homeowners make:
| 15-Year Mortgage | 30-Year Mortgage | |
|---|---|---|
| Loan Amount | kr3,675,000 | kr3,675,000 |
| Interest Rate | 6.0% | 6.5% |
| Monthly Payment | kr31,028 | kr23,226 |
| Total Payments | kr5,584,950 | kr8,361,360 |
| Total Interest Paid | kr1,909,950 | kr4,686,360 |
| Interest Savings | kr2,776,410 saved with 15-year | |
The 15-year mortgage saves kr2,776,410 in interest but requires kr7,802/month more. The 30-year's lower payment provides flexibility — you can always make extra payments to pay off faster without being locked into the higher obligation. Many financial advisors suggest taking the 30-year but paying it as if it were a 20-year mortgage.
How Much House Can You Afford?
Several rules of thumb help determine how much mortgage you can responsibly take on:
- The 28% Rule: Your monthly housing costs (mortgage + insurance + property tax) should not exceed 28% of your gross monthly income. On a kr840,000/year salary: kr840,000 / 12 = kr70,004/month × 0.28 = kr19,604 maximum housing payment.
- The 36% Rule (28/36 Rule): Total monthly debt (housing + car loans + student loans + credit cards) should not exceed 36% of gross income.
- The 3x Rule: Purchase price should not exceed 3× your annual gross income. At kr840,000/year, that suggests a maximum price of kr2,520,000.
Lenders also assess your debt-to-income ratio (DTI). Most conventional lenders require a DTI below 43%, with the best rates going to borrowers under 36%.
Down payment impact: A 20% down payment avoids Private Mortgage Insurance (PMI), which costs 0.5–1.5% of the loan annually. On a kr4,200,000 home, that is kr1,743–kr5,250/month in extra cost until you reach 20% equity.
Amortization: How Payments Split Between Principal and Interest
In the early years of a mortgage, the vast majority of each payment goes toward interest, not principal. This is called amortization:
| Payment # | Payment Amount | Interest Portion | Principal Portion | Balance Remaining |
|---|---|---|---|---|
| 1 | kr19,908 | kr17,062 | kr2,846 | kr3,147,154 |
| 12 | kr19,908 | kr16,916 | kr2,992 | kr3,128,780 |
| 60 (yr 5) | kr19,908 | kr16,264 | kr3,644 | kr3,002,811 |
| 180 (yr 15) | kr19,908 | kr13,440 | kr6,468 | kr2,476,824 |
| 300 (yr 25) | kr19,908 | kr7,959 | kr11,949 | kr1,460,844 |
| 360 (yr 30) | kr19,908 | kr105 | kr19,803 | kr0.00 |
Based on kr3,150,000 at 6.5% for 30 years. Notice that after 5 years of payments, you have only paid down ~kr147,000 of principal. This is why making extra principal payments early is so impactful.
Mortgage Rate Factors and How to Get the Best Rate
Mortgage rates vary based on both market conditions and personal financial factors. Here is what affects your rate:
- Credit score: The most impactful personal factor. A score of 760+ typically qualifies for the best rates. Below 620, some lenders will not approve conventional loans.
| Credit Score Range | Approximate Rate Adjustment | Monthly Payment Difference* |
|---|---|---|
| 760–850 | Best available rate (e.g., 6.5%) | — |
| 700–759 | +0.25% | +kr525/month |
| 680–699 | +0.5% | +kr1,060/month |
| 660–679 | +0.75% | +kr1,606/month |
| 640–659 | +1.5% | +kr3,266/month |
| 620–639 | +2.25% | +kr4,977/month |
*Based on a kr3,150,000 30-year mortgage. A poor credit score could cost kr4,977 more per month — kr1,791,720 extra over the life of the loan.
- Down payment: 20%+ gets the best rates and eliminates PMI
- Loan type: 15-year rates are typically 0.5–0.75% lower than 30-year rates
- Loan size: Jumbo loans (above conforming limits) typically carry higher rates
- Market conditions: The Federal Reserve's benchmark rate strongly influences mortgage rates
Strategies to Pay Off Your Mortgage Faster
Even small additional payments can save tens of thousands in interest and years off your mortgage:
- Biweekly payments: Instead of 12 monthly payments, make 26 half-payments per year. This results in one extra full payment per year, reducing a 30-year mortgage to approximately 25–26 years and saving ~kr315,000 in interest on a typical mortgage.
- Extra monthly principal payments: Adding kr2,100/month to a kr3,150,000 mortgage at 6.5% saves over kr630,000 in interest and cuts 5+ years off the loan.
- Lump sum payments: Directing tax refunds, bonuses, or inheritances to mortgage principal is highly effective, especially in the early years.
- Refinancing: If rates drop 0.75% or more below your current rate, refinancing can save significantly. Calculate the break-even point: closing costs ÷ monthly savings = months to break even.
Before making extra payments, ensure your mortgage has no prepayment penalty and consider whether the money might earn more in tax-advantaged investments (401k, IRA) if your mortgage rate is low.
"Before taking on a mortgage, consider your total monthly housing costs — principal, interest, taxes, and insurance. Most financial experts recommend keeping housing costs below 28% of gross monthly income to maintain financial stability."
💡 Visste du?
- The word "mortgage" comes from Old French "mort gage" meaning "death pledge" — the debt "dies" when paid off, or the pledge "dies" if the borrower defaults.
- The 30-year fixed-rate mortgage was introduced in the US in 1934 by the Federal Housing Administration to revive the housing market after the Great Depression.
- Before amortization tables (19th century), calculating monthly mortgage payments required iterative arithmetic — a process that could take hours.
Sist oppdatert: March 2026
Frequently Asked Questions
How much house can I afford?
A common guideline is the 28/36 rule: spend no more than 28% of gross monthly income on housing costs, and no more than 36% on total debt payments. On a kr787,500/year salary, that means a maximum housing payment of about kr18,375/month.
Should I choose a 15 or 30-year mortgage?
A 15-year mortgage has higher monthly payments but saves dramatically on interest — often kr1,575,000–kr3,150,000 over the loan life. A 30-year mortgage provides lower, more flexible payments. Many experts suggest a 30-year mortgage with aggressive extra payments, giving you flexibility without being locked in.
What affects my mortgage interest rate?
The biggest factors are: credit score (760+ gets best rates), down payment size (20%+ is ideal), loan term (15-year rates are lower), loan type (conventional vs FHA vs VA), and current Federal Reserve monetary policy which influences all rates.
What is PMI and how do I avoid it?
Private Mortgage Insurance (PMI) is required on conventional loans when your down payment is less than 20%. It costs 0.5–1.5% of the loan per year (kr15,750–kr47,250 annually on a kr3,150,000 loan). Avoid it by putting 20%+ down, or request cancellation once your equity reaches 20%.
What is the difference between interest rate and APR?
The interest rate is the cost of borrowing the principal. APR (Annual Percentage Rate) includes the interest rate plus other loan costs (origination fees, points, mortgage insurance). APR is always higher than the interest rate and gives a more accurate picture of total loan cost. Use APR to compare different loan offers.
How does a mortgage payoff amortization work?
In the early years of a mortgage, most of each payment is interest. Over time, more goes to principal. For example, on a kr3,150,000 mortgage at 6.5%, your first payment is about 86% interest and 14% principal. By year 25, it flips to roughly 40% interest and 60% principal.
Is it better to put more money down or pay down the mortgage faster?
A larger down payment reduces PMI, lowers your loan amount, and may improve your rate. Extra mortgage payments reduce interest costs and build equity faster. The best choice depends on your current mortgage rate vs. expected investment returns — if your mortgage rate is 7% and investments return 10%, extra investments may win.
What credit score do I need for a mortgage?
Conventional loans generally require a minimum of 620, but rates are best at 760+. FHA loans allow scores as low as 580 with a 3.5% down payment, or 500 with a 10% down payment. VA and USDA loans have no official minimum but lenders typically require 620+.