We hear about it all the time. There are few things in the financial world that are givens but even in the most uncertain environment, interest or in terms of stocks, dividends are one of those income streams that make us feel good. Often seen as unchanging, nearly all consumers understand interest because they often pay it on their loans or they earn it in their savings accounts.
If you’ve ever applied for a car loan, one of the items you look at first is the interest rate. We all understand that the higher the interest rate, the more money we will pay in the end but let’s look at a few other facts about interest rates that you may not know.
Simple Interest is Not as Simple as You Think
Simple interest is the easiest type of interest to understand. If you loaned a buddy $100 and told him that when he pays you back, he has to pay you $106, you charged him 6% on the loan. In finance terms, simple interest is calculated by multiplying the principal amount (100) times the rate (6%) times the amount of time (let’s say 1 year) 100 X .06 X 1 = $6. Pretty easy.
Banks are much more savvy than that, though. They aren’t going to give you $10,000 for a car and charge you 6% each year spread equally between interest and principal. They front load the interest in case you pay the $10,000 off early. If you looked at the amortization table that came with your loan documents you noticed that more interested is factored in to the first few years of the loan and as you reach the end, it becomes almost all principal.
This is far from “simple” and if you saw the calculations, you would agree. If you didn’t know what an amortization table was before now, just remember that it lays out how your total payment is broken down. If you want to see how interest is frontloaded in your loan, you can create your own amortization table by going to www.amortization-calc.com.
If you own certain fixed income investments the interest being paid to you is paid using a simple interest formula. You can reinvest your dividends (called the coupon) if you would like but it’s not compounded within the investment itself.
Compound Interest is Simpler than You Think
Compound interest is more difficult to calculate and for most of our purposes, the way it is calculated isn’t overly important. Since there is a seemingly endless supply of compound interest calculators, we won’t worry about the particulars but here’s what you need to know when you’re shopping around: Unless you’re working with six figure numbers, the type of compounding is unimportant. Let’s look at an example:
I found a compound interest rate calculator at webmath.com and came up with these figures:
Let’s say that you have $50,000 in a 1 year Guaranteed Investment Certificate at 5% interest that is compounded monthly. After one year you will have in your account $52,558.09.
Now, let’s say that you have that money in a GIC from a different bank but the interest is compounded daily. After one year you will have in your account $52,563.37.
Although many unknowing consumers find themselves comparing the different types of compounding, in reality, it makes very little difference. Some may argue that if you’re investing in GICs for 30 years that $5 difference adds up. It’s true. Over 30 years that would be about $674 but once 30 years of inflation eats in to it, that $674 is far less impressive.
Look at the “Y” Instead of the “R”
When comparing loan rates, don’t look at the APR. The APR or annual percentage rate is the amount of money you would pay or receive if the interest was calculated using simple interest. Since the APR doesn’t account for any compounding, look at the APY or annual percentage yield. The APY takes into account the type of compounding used.
For example, if a car dealership offered to finance a $10,000 loan at a 5% APR, you could go to another dealership and get the same APR but pay those couple of dollars more per year because of the compounding. A $10,000 loan at 5% compounded daily has an APY of 5.13% but if it is compounded monthly the APY is 5.12%. (By the way, the difference annually is all of $1.05)
Don’t Count on Compounding
If you’re investing, there’s no doubt that when you reinvest your returns over time, compounding does wonders for your portfolio. You can’t live on your RRSP contribution alone for your entire retirement so you have to rely on compounding to grow your nest egg.
However, you can’t use compounding as an excuse to not take an active part in the management of your retirement plan. If the world markets have another meltdown, compounding isn’t going to save you if you’re close to retirement. Make sure you have a qualified and more importantly, approachable investment advisor.
Tom Drake
Tom Drake is the owner and head writer of the award-winning MapleMoney. With a career as a Financial Analyst and over a decade writing about personal finance, Tom has the knowledge to help you get control of your money and make it work for you.
View all posts by Tom Drake
FAQs
Simple interest is calculated on the principal, or original, amount of a loan. Compound interest is calculated on the principal amount and the accumulated interest of previous periods, and thus can be regarded as “interest on interest.”
What is the basics of compound interest? ›
Compound interest is calculated by multiplying the initial principal amount by one plus the annual interest rate raised to the number of compound periods minus one. The total initial principal or amount of the loan is then subtracted from the resulting value. Katie Kerpel {Copyright} Investopedia, 2019.
How do you know if you should use simple or compound interest? ›
Which Is Better, Simple or Compound Interest? It depends on whether you're saving or borrowing. Compound interest is better for you if you're saving money in a bank account or being repaid for a loan. If you're borrowing money, you'll pay less over time with simple interest.
What is an example of simple and compound interest? ›
With simple interest, you would add 5% of $100 - $5 - each year for 10 years, for a total of $50 worth of interest. You would end up owing $150 after 10 years. If you were paying 5% interest compounded annually, though, you would take 5% of the amount each year - including any interest that has already accumulated.
What is simple interest for dummies? ›
The formula to determine simple interest is an easy one. Just multiply the loan's principal amount by the annual interest rate by the term of the loan in years. This type of interest usually applies to automobile loans or short-term loans, although some mortgages use this calculation method.
How much is $1000 worth at the end of 2 years if the interest rate of 6% is compound? ›
Basic compound interest
For other compounding frequencies (such as monthly, weekly, or daily), prospective depositors should refer to the formula below. Hence, if a two-year savings account containing $1,000 pays a 6% interest rate compounded daily, it will grow to $1,127.49 at the end of two years.
What is compound vs simple interest for dummies? ›
Simple interest is calculated on the principal, or original, amount of a loan. Compound interest is calculated on the principal amount and the accumulated interest of previous periods, and thus can be regarded as “interest on interest.”
How do you calculate simple interest? ›
Simple interest is calculated by multiplying the principal, the amount of money that is initially invested or borrowed, by the rate, the speed at which the interest grows, and the time, how long money is being invested or borrowed. In other words, the formula for simple interest is I = P R T .
What is the formula for calculating simple interest? ›
How to Calculate Simple Interest? Simple Interest is calculated using the following formula: SI = P × R × T, where P = Principal, R = Rate of Interest, and T = Time period.
Is home loan simple or compound interest? ›
The important thing to note for Home Loan interest rate is that it is compounded interest and not simple interest. In other words, you don't pay interest only on the principal amount, but you pay interest on the principal amount plus the interest accrued.
You want to know your total interest payment for the entire loan. To start, you'd multiply your principal by your annual interest rate, or $10,000 × 0.05 = $500.
What is 4% interest on $10000? ›
For example, if you put $10,000 into a savings account with a 4% annual yield, compounded daily, you'd earn $408 in interest the first year, $425 the second year, an extra $442 the third year and so on. After 10 years of compounding, you would have earned a total of $4,918 in interest.
How do you calculate compound interest? ›
Compound interest is calculated by multiplying the initial loan amount, or principal, by one plus the annual interest rate raised to the number of compound periods minus one. This will leave you with the total sum of the loan, including compound interest.
How do you explain compound interest to a child? ›
Put simply, compound interest is when you earn interest on both the money you've saved and the interest you've already earned.
Are there 2 formulas for simple interest? ›
Summary. This topic uses two formulas: Interest=Principal×Rate×TimeI=PRTAmount=Principal+InterestA=P+I Principal is your starting amount of money. Rate is the interest rate in a decimal. Time is number of times the Interest is taken, usually in years.
What is compounding for dummies? ›
Want to help build wealth? Make money from your money. Compounding is a powerful investing concept that involves earning returns on both your original investment and on returns you received previously. For compounding to work, you need to reinvest your returns back into your account.
How do you explain compound interest with examples? ›
For example, if you deposit $1,000 in an account that pays 1 percent annual interest, you'd earn $10 in interest after a year. Thanks to compound interest, in Year Two you'd earn 1 percent on $1,010 — the principal plus the interest, or $10.10 in interest payouts for the year.
What is the basic formula for compounding? ›
The formula for compound interest is A=P(1+rn)nt, where A represents the final balance after the interest has been calculated for the time, t, in years, on a principal amount, P, at an annual interest rate, r. The number of times in the year that the interest is compounded is n.
