Help with NISA compound interest calculation

[Roger Van Zant]

Anyone know how to work out compound interest? Or can anyone recommend an online calculator for this?

Here is what I want to work out:

I will have 7.2 million yen in my new NISA by age 47 (2024 : put in 3.6m, 2025 : put in another 3.6m).
I will leave that in there until age 70.

Plus, will continue to pay in 500,000 yen per year, every year, until I reach 68; so 21 more years.

I want to know how much I can expect to have in there by the time I am 70.

7,200,000 yen + (500,000 yen x 21 years).

I am guessing around 3% for interest (being conservative).

How do I work this out?

[TokyoBoglehead]

Anyone know how to work out compound interest? Or can anyone recommend an online calculator for this?

Here is what I want to work out:

I will have 7.2 million yen in my new NISA by age 47 (2024 : put in 3.6m, 2025 : put in another 3.6m).
I will leave that in there until age 70.

Plus, will continue to pay in 500,000 yen per year, every year, until I reach 68; so 21 more years.

I want to know how much I can expect to have in there by the time I am 70.

7,200,000 yen + (500,000 yen x 21 years).

I am guessing around 3% for interest (being conservative).

How do I work this out?

Here is a dead simple calculator.

https://www.investor.gov/financial-tool ... calculator

[Roger Van Zant]

Anyone know how to work out compound interest? Or can anyone recommend an online calculator for this?

Here is what I want to work out:

I will have 7.2 million yen in my new NISA by age 47 (2024 : put in 3.6m, 2025 : put in another 3.6m).
I will leave that in there until age 70.

Plus, will continue to pay in 500,000 yen per year, every year, until I reach 68; so 21 more years.

I want to know how much I can expect to have in there by the time I am 70.

7,200,000 yen + (500,000 yen x 21 years).

I am guessing around 3% for interest (being conservative).

How do I work this out?

Here is a dead simple calculator.

https://www.investor.gov/financial-tool ... calculator

Thanks.
I wish I were better at using Excel...!

[Bubblegun]

This is what I use.
The calculator site.
I like it cause I can change currency and there are a bunch of other things on
https://www.thecalculatorsite.com/finan ... ulator.php

[Roger Van Zant]

This is what I use.
The calculator site.
I like it cause I can change currency and there are a bunch of other things on
https://www.thecalculatorsite.com/finan ... ulator.php

Thank you!
This is awesome, as it also teaches you the mathematical formulae.
Very useful.

[Tkydon]

In Excel

In Cell A3, type 7.00%
(This is the Average Annual Growth Rate you expect into the future. More conservative is better... You can change the value here to change all the subsequent calculations for projected future values)

In Cell A6, type 22
Fill down A7, 21
A8, 20
And so on
(Number of years left to retirement)

In Cell B6, type 3,600,000
In Cell B7, type 3,600,000
In Cell B8, type 500,000
And so on down
(Amount invested every year...)

In Cell C6, type formula =$B6*(1+$A6)^$A$3
Fill this all the way down
(Calculates the Future Value at Retirement for the Value in the cell to the left, multipled by the Compound Interest 1 + 7.00% in A3 to the power of the number of years to retirement in the extreme left cell)

Then a couple of cells below, type formula =sum($C6:$C<one cell above>)
Put the number where it says <one cell above>
(Calculates the Total value of all the Future Values of all the years between now and retirement to achieve the Projected Value of your Nestegg at Retirement)

You can now make assumptions by changing the % in Cell A3 to see the range of reasonable expectations...
We do not know what rate of growth the future holds. The 10 Year Average CAPE Ratio implies that the returns delivered over the next 10 years will not be as great as the returns over the last 10 or 20 years, so better to be more conservative in your expectations...
Try 3% and 10%, but expect the lower, and rejoice if it turns out to be the higher...

[zeroshiki]

Well if you're giving Excel tips then why not just use the FV Excel function

[Tkydon]

Well if you're giving Excel tips then why not just use the FV Excel function

Because, then he'd never learn how to do the calculation...

[banders]

Go buy a pinafore. You're going to be an oku-san!

[Roger Van Zant]

In Excel

In Cell A3, type 7.00%
(This is the Average Annual Growth Rate you expect into the future. More conservative is better... You can change the value here to change all the subsequent calculations for projected future values)

In Cell A6, type 22
Fill down A7, 21
A8, 20
And so on
(Number of years left to retirement)

In Cell B6, type 3,600,000
In Cell B7, type 3,600,000
In Cell B8, type 500,000
And so on down
(Amount invested every year...)

In Cell C6, type formula =$B6*(1+$A6)^$A$3
Fill this all the way down
(Calculates the Future Value at Retirement for the Value in the cell to the left, multipled by the Compound Interest 1 + 7.00% in A3 to the power of the number of years to retirement in the extreme left cell)

Then a couple of cells below, type formula =sum($C6:$C<one cell above>)
Put the number where it says <one cell above>
(Calculates the Total value of all the Future Values of all the years between now and retirement to achieve the Projected Value of your Nestegg at Retirement)

You can now make assumptions by changing the % in Cell A3 to see the range of reasonable expectations...
We do not know what rate of growth the future holds. The 10 Year Average CAPE Ratio implies that the returns delivered over the next 10 years will not be as great as the returns over the last 10 or 20 years, so better to be more conservative in your expectations...
Try 3% and 10%, but expect the lower, and rejoice if it turns out to be the higher...

Thank you for this! Sorry for my late reply.
I played around with the NISA investment amounts a bit, then also used the same system to project my iDeCo and shitty company DB fund.
Here's how it worked out:
https://ibb.co/1J8kJ7W

Does this look right to you?
I think I screwed up somewhere.
According to this Excel sheet, 3,6000,000 will be worth 4,211,035 after 22 years at 5% interest.
Yet when I put these same numbers into the calculator at www.thecalculatorsite.com, I get 10,790,310:
https://ibb.co/4Vf0qyw

What's going on?