Interest Rates
Several Factors Affect Your Mortgage Rate
Learn about all of the different factors that can change the interest rate of a mortgage.
Annual Percentage Rate (APR)
The true cost of the loan to the borrower expressed in the form of a yearly rate.
Lock In Your Interest Rate
What is a rate lock for and why do you need one.
Closing Costs Explained
Closing costs are the actual expenses that the lender incurs in the origination of a new home loan.
Should I Pay Points
A point is an upfront fee that reduces your monthly interest rate and total interest due over the life of the loan.
Mortgage Calculations by Hand
Learn the formulas for calculating interest rates and payments.
Several Factors Affect Your Mortgage Rate
The amount of your loan can increase your interest rate if the amount financed exceeds the conforming loan limits established by Fannie Mae and Freddie Mac. The conforming loan limit changes at the beginning of each year.
Shorter loans, such as 20 year or 15 year note, can save you thousand of dollars in interest payments over the life of the loan, but your monthly payments will be higher. An adjustable rate mortgage may get you started with a lower interest rate than a fixed rate mortgage, but your payments could get higher when the interest rate changes.
A larger down payment “ greater than 20% " will give you the best possible rate. Down payments of 5% or less should expect to pay a higher rate as you are starting with less equity as collateral. If you've got the cash now and want to lower your payments, you can pay on your loan to lower your mortgage rate. It's a simple concept, really: In exchange for more money upfront, lenders are willing to lower the interest rate they charge, cutting the borrower's payments. Closing costs are fees paid by the lender, if you don't want to pay all of the closing costs, expect a higher rate which will pay the lender additional interest over the life of the loan.
Credit quality and debttoincomeratio affect the terms of your loan through FICO Score. If you have good credit and your monthly income far surpasses your monthly debt obligations, you will get approved at a lower interest rate. However, if your monthly income barely covers your minimum debt obligations, even if you have a credit report, you will not receive the lowest available interest rate.
Annual Percentage Rate (APR)
A tool used to compare loans across different loan programs is the Annual Percentage Rate (APR). The Federal Truth in Lending law requires mortgage companies to disclose the APR when they advertise a rate. It is designed to represent the true cost of the loan to the borrower, expressed in the form of a yearly rate. The purpose is to prevent lenders from hiding fees and up front costs behind low advertised interest rates.
One confusing aspect of APRs is that the APR on 15 year loans will carry a higher relative rate due to the fact that the points are amortized over the 15 year term rather than the 30 year term. When a Regulation Z (the mortgage company's disclosure of cost for the loan) is prepared for a buyer/borrower, the prepaid interest is also included in the APR calculation.
Even lenders admit it is confusing since it includes some, but not all, of the various fees and insurance premiums that accompany a mortgage. The rules for calculation of this number have not been clearly defined, so APRs vary from lender to lender and from loan to loan, depending on which types of fees and charges are included.
In addition, the APR model is flawed in that when a product is variable and tied to a market index, the index is assumed to never change. This obviously is an invalid assumption that can lead again to a number, which in fact can not be compared, from one quoting source to another.
Finally, the APR won't tell you anything about balloon payments and prepayment penalties or how long your rate is locked for. You can use APRs as a guideline to shop for loans, but you should not depend solely on the APR in choosing which loan is best for your needs.
Lock In Your Interest Rate
A lock, also called a rate lock or rate commitment, is a lender's promise to hold a certain interest rate and a certain number of points for you, usually for a specified period of time, while your loan application is processed. Depending upon the lender, you may be able to lock in the interest rate and number of points that you will be charged when you file your application, during processing of the loan, when the loan is approved, or later.
Shorter loans, such as a 20 year or 15 year note, can save you thousand of dollars in interest payments over the life of the loan, but your monthly payments will be higher. An adjustable rate mortgage may get you started with a lower interest rate than a fixed rate mortgage, but your payments could get higher when the interest rate changes.
A larger down payment greater than 20% will give you the best possible rate. With a down payment of 5% or less, you should expect to pay a higher rate as you are starting with less equity as collateral. If you've got the cash now and want to lower your payments, you can pay points on your loan to lower your mortgage rate. It's a simple concept, really. In exchange for more money up front, lenders are willing to lower the interest rate they charge, cutting the borrower's payments. Closing costs are fees paid by the lender, if you do not want to pay all of the closing costs, expect a higher rate which will pay the lender additional interest over the life of the loan.
Your credit quality and debttoincome ratio affect the terms of your loan through your FICO Score. If you have good credit and your monthly income far surpasses your monthly debt obligations, you will get approved at a lower interest rate. However, if your monthly income barely covers your minimum debt obligations, even if you have a good credit report, you will not receive the lowest available interest rate.
Closing Costs Explained
Closing costs are the actual expenses that the lender incurs in the origination of a new home loan. Some of the costs are related to your loan application, such as the expense of a credit report on all applicants. Other fees are related to the house itself, such as the property appraisal. Others are payment to the lender for processing your application, such as the loan origination fee.
Unless the seller offers to pay them for you, these expenses are charged to the buyer and often runs between 2 and 3 percent of the amount being borrowed. Because different states have different fees and taxes that are a part of these costs, it's impossible to generalize nationwide.
Common closing costs can include processing and underwriting fee, mortgage insurance premium, appraisal fee, the cost of a credit report, tax service fee, application, commitment, wire transfer fee, etc. Escrow accounts are often required for many loans for homeowners insurance, real estate taxes, and homeowners associations and require cash deposits at closing.
After your initial meeting with a mortgage professional, you should receive a Good Faith Estimate or Loan Estimate that includes all the estimated costs to close your loan.
Should I Pay Points?
A point, which equals 1% of the total loan amount, is an upfront fee that reduces your monthly interest rate and total interest due over the life of a loan. This means that a one point loan will always have a lower interest rate than a no point loan. Paying points is in essence a trade off between paying money now versus paying money later.
Deciding whether to pay points depends on how long you are looking to keep the loan. We suggest paying points up front if you plan on keeping the loan for at least four years to ensure that you recoup the costs through lower monthly payments. If you think that you might move within the next four years or might want to refinance because the market rate is declining, then you probably would be better off with a no point loan.
Lenders allow you to choose amongst a variety of rate and point combinations for the same loan product. Therefore, when comparing rates from different lenders, make sure you compare the associated points and rate combinations of the offered program. The published Annual Percentage Rate (APR) is a tool used to compare different terms, offered rates, and points among different lenders and programs.
Mortgage Calculations by Hand
First you must define some variables to make it easier to set up: P = principal, the initial amount of the loan I = the annual interest rate (from 1 to 100%) L = length, the length (in years) of the loan, or at least the length over which the loan is amortized.
The following assumes a typical conventional loan where the interest is compounded monthly. First we'll define two more variables to make the calculations easier: J = monthly interest in decimal form = I / (12 x 100) N = number of months over which loan is amortized = L x 12
Now for the big monthly payment (M) formula ... it is:
J M = P x  1  ( 1 + J ) ^ N where 1 is the number one (it does not appear too clearly on some browsers)
So to calculate it, you would first calculate 1 + J then take that to the N (minus N) power, subtract that from the number 1. Now take the inverse of that (if you have a 1/X button on your calculator push that). Then multiply the result times J and then times P.
The oneliner for a program would be (adjust for your favorite language):
M = P * ( J / (1  (1 + J) ** N))
So now you should be able to calculate the monthly payment, M. To calculate the amortization table you need to do some iterations (i.e. a simple loop). Here are the simple steps :
Step 1: Calculate H = P x J, this is your current monthly interest
Step 2: Calculate C = M  H, this is your monthly payment minus your monthly interest, so it is the amount of principal you pay for that month
Step 3: Calculate Q = P  C, this is the new balance of your principal of your loan.
Step 4: Set P equal to Q and go back to Step 1: You thusly loop around until the value Q (and hence P) goes to zero.
Many people have asked how to find N (number of payments) given the payment, interest and loan amount. The answer to the actual formula is in the book: The Vest Pocket Real Estate Advisor by Martin Miles (Prentice Hall). Here's the formula:
N = 1/Q * (LN(1(B/M)*(R/Q)))/LN(1+(R/Q))
Where:

Q = amount of annual payment periods

R = interest rate

B = principle

M = payment amount

N = amount payment period

LN = natural logarithm