Discrepancy in MSE ISA calculator?

nick5990 Forumite Posts: 19
Fourth Anniversary 10 Posts
edited 8 July at 9:25PM in ISAs & tax-free savings
I emailed this to brokenlink @ MSE email address a few days ago (23/06/23). I haven't received a reply yet, so thought I'ld also post this to the forum.
Screenshots are posted below rather than attachments in the email.

See attached two marked up screenshots of results from using your calculator on page linked below

First one (suffix "_2")  uses target of £1m, starting from £100k, saving £600 per month with an interest rate of 4%. Output is 36 years.

Second one (suffix "_3") uses target of £1m, starting from £100k, with an interest rate of 4%, saving for 36 years. output is £1,159 per month.

Please advise on the discrepancy?


  • eskbanker
    eskbanker Forumite Posts: 27,472
    Part of the Furniture 10,000 Posts Name Dropper Photogenic
    £600 per month looks to be the right answer of the two from a quick Excel check....

    However, in the real world, it's a moot point, because anyone looking to accumulate £1m over 36 years wouldn't use a cash savings account, because of the effects of inflation, which don't appear to be factored into that calculator!
  • masonic
    masonic Forumite Posts: 21,451
    Part of the Furniture 10,000 Posts Photogenic Name Dropper
    In the first example, you'd hit your target in the 18th year, so there seems to be an issue with that one. The other two "questions" seem to be internally consistent with each other and correct.
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