2. Effective Rate of Interest:
The Effective Rate of interest is the rate of interest actually
earned on an investment or paid on a loan as a result of
compounding the interest over a given period of time. It is
usually higher than the nominal rate and is used to compare
different financial products that calculate annual interest
with different compounding periods โ weekly, monthly,
quarterly, semi annually, and yearly. Increasing the number
of compounding periods makes the effective interest rate
increase as time goes by.
3. Formula for Effective Rate of Interest:
Effective Rate of Interset = 1 +
nominal interest rate
number of compounding periods
number of compounding periods
โ 1
๐๐๐๐๐๐ญ๐ข๐ฏ๐ ๐๐๐ญ๐ ๐จ๐ ๐๐ง๐ญ๐๐ซ๐ฌ๐๐ญ = ๐ +
๐
๐
๐
โ ๐
OR
i = ๐ง๐จ๐ฆ๐ข๐ง๐๐ฅ ๐ข๐ง๐ญ๐๐ซ๐๐ฌ๐ญ ๐ซ๐๐ญ๐
m = ๐ง๐ฎ๐ฆ๐๐๐ซ ๐จ๐ ๐๐จ๐ฆ๐ฉ๐จ๐ฎ๐ง๐๐ข๐ง๐ ๐ฉ๐๐ซ๐ข๐จ๐๐ฌ
Where
4. Nominal Rate of Interest:
A nominal rate interest is a stated rate indicated by a
financial instrument that is issued by a lender or guarantor.
This rate is the basis for computation to derive the interest
amount resulting from compounding the principal plus
interest over a period of time. This is the actual monetary
price that borrowers pay to lenders or that investors receive
from issuers.
5. Compounding Period:
A compounding period is the time period after which the
outstanding loan or investmentโs interest is added to the
principal amount of said loan or investment. The period can
be daily, weekly, monthly, quarterly, or semi-annually,
depending on the terms agreed upon by the parties
involved. As the number of compounding periods increases
so does the amount of interest earned or paid on the money
used. Quarterly compounding produces higher returns than
semi-annual compounding, while monthly compounding
generates more than quarterly, and daily compounding
generates more than monthly.
6. Example-1
Find the effective rate of interest
a) 6% compounded semi-annually.
b) 6% compounded quarterly.
c) 6% compounded monthly.
Solution:
(a)
m
e
2
e
i 6%
6
0.06
100
m 2
we know that
i
r (1 ) 1
m
0.06
r (1 ) 1
2
๏ฝ ๏ฝ ๏ฝ
๏ฝ
๏ฝ ๏ซ ๏ญ
๏ฝ ๏ซ ๏ญ
7. 2
e
e
e
e
r (1 0.03) 1
r 1.0609 1
r 0.609
r 6.09%
๏ฝ ๏ซ ๏ญ
๏ฝ ๏ญ
๏ฝ
๏ฝ
(b)
m 4
e
4 4
e
e
i 6%
6
0.06
100
m 4
we know that
i 0.06
r (1 ) 1 (1 ) 1
m 4
r (1 0.015) 1 (1.015) 1
r 1.0614 1 0.0614 6.14%
๏ฝ ๏ฝ ๏ฝ
๏ฝ
๏ฝ ๏ซ ๏ญ ๏ฝ ๏ซ ๏ญ
๏ฝ ๏ซ ๏ญ ๏ฝ ๏ญ
๏ฝ ๏ญ ๏ฝ ๏ฝ
8. (c)
m 12
e
i 6%
6
0.06
100
m 12
we know that
i 0.06
r (1 ) 1 (1 ) 1
m 12
๏ฝ ๏ฝ ๏ฝ
๏ฝ
๏ฝ ๏ซ ๏ญ ๏ฝ ๏ซ ๏ญ
12 12
e
e
r (1 0.005) 1 (1.005) 1
r 1.0617 1 0.0617 6.17%
๏ฝ ๏ซ ๏ญ ๏ฝ ๏ญ
๏ฝ ๏ญ ๏ฝ ๏ฝ
Comments
๐๐จ๐ฆ๐ฉ๐จ๐ฎ๐ง๐๐๐ ๐๐๐๐ โ ๐๐ง๐ง๐ฎ๐๐ฅ๐ฅ๐ฒ ห ๐๐จ๐ฆ๐ฉ๐จ๐ฎ๐ง๐๐๐ ๐ช๐ฎ๐๐ซ๐ญ๐๐ซ๐ฅ๐ฒ ห ๐๐จ๐ฆ๐ฉ๐จ๐ฎ๐ง๐๐๐ ๐ฆ๐จ๐ง๐ญ๐ก๐ฅ๐ฒ
๐. ๐๐% < ๐. ๐๐% < ๐. ๐๐%