I'll derive the formula for you, and give an example in which your deposit is compounded monthly.
D = deposit
y = number of years deposited
t = number of times compounded annually
A = 6.5 %
r = A / t
ty = number of periods compounded
D ( 1 + r ) ty = 2D
(1 + r )ty = 2
ln ((1 + r )ty) = ln (2)
ty ln(1 + r ) = ln (2 )
ty = [ln(2)] / [ln (1 + r)]
ty = [ ln(2) ] / [ ln ( 1 +( 0.065/12) )]
ty = 128.31
It will take 128.31 months for you deposit to double if compounded monthly.
After 129 months you will more than double your deposit.
If your deposit is compounded differently ( daily, quarterly or annually) make the necessary
substitutions to get the results you're looking for.
D = deposit
y = number of years deposited
t = number of times compounded annually
A = 6.5 %
r = A / t
ty = number of periods compounded
D ( 1 + r ) ty = 2D
(1 + r )ty = 2
ln ((1 + r )ty) = ln (2)
ty ln(1 + r ) = ln (2 )
ty = [ln(2)] / [ln (1 + r)]
ty = [ ln(2) ] / [ ln ( 1 +( 0.065/12) )]
ty = 128.31
It will take 128.31 months for you deposit to double if compounded monthly.
After 129 months you will more than double your deposit.
If your deposit is compounded differently ( daily, quarterly or annually) make the necessary
substitutions to get the results you're looking for.