I built a new calculator for Networthify: Understanding recurring costs

[kablamo]

Hi forum people!  Recently I got off my butt and built another little tool.  It helps me better understand the total cost of recurring charges.   Some of the interesting bits:

- Calculate total cost after x years
- Calculate the nest egg required to support this recurring charge in retirement
- Calculate how many hours of work are required to pay those costs

I especially recommend using the savings rate option.  Any feedback would be awesome. 
http://networthify.com/calculator/recurring-charges

This calculator was inspired mostly by this MMM post:
http://www.mrmoneymustache.com/2011/04/15/getting-started-3-eliminate-short-termitis-the-bankruptcy-disease/

[TLV]

Link

Feedback:
* The "A workday lasts" field doesn't seem to affect anything.
* Consider adding a "startup-cost" - for example, a cell phone with plan might cost $200 up front and then $50/mo after that.
* The "savings rate" feature seems like it should only apply to the values on the right ("how long will it take to save up enough to support this with passive income"?). If you have 50% savings and make $20/hour, it still only takes 5 hours to make $100 - the $100 is included in the 50% of expenses.

[kablamo]

Thanks for providing the link TLV.  I forgot.  Great feedback too.  I fixed the workday field bug.  I think you are right about the savings rate as well.  Thats probably going to be a little confusing either way to someone.

[arebelspy]

Tis should be an easy fix, and will help readability.

Translate into years if at least 365 days. Answers like 570dys 2hrs isn't as helpful as seeing it years/days/hours.

Another neat tool.

Thanks for sharing.

[kablamo]

Thanks arebelspy!  I implemented your 'years' suggestion. 

[Able was I ERE]

Translate into years if at least 365 days. Answers like 570dys 2hrs isn't as helpful as seeing it years/days/hours.

Thanks arebelspy!  I implemented your 'years' suggestion.

Nice improvement! 

I would suggest going one step further and doing the following:

• use the financial industry standard of 252 work days per year, which makes it easier to
• add months (21 days per month)

Since most people don't work week-ends, this would more closely match how many more years you'd have to have a job in order to support your recurring expense. 

[arebelspy]

Translate into years if at least 365 days. Answers like 570dys 2hrs isn't as helpful as seeing it years/days/hours.

Thanks arebelspy!  I implemented your 'years' suggestion.

Nice improvement! 

I would suggest going one step further and doing the following:

• use the financial industry standard of 252 work days per year, which makes it easier to
• add months (21 days per month)

Since most people don't work week-ends, this would more closely match how many more years you'd have to have a job in order to support your recurring expense.

It'd be cool to add that and display both.  Or, if you want to get really fancy, in the hidden options allow an input for how many days they work per year (and include the above info about number of weekend days, etc), so people can subtract off the amount of vacation and such that they get.

[kablamo]

Thanks Able!  I added a 'Working days per year' field and it defaults to 252.   Hmm now that I am doing some math I think the default should be closer to 240 or 230.  Meh.  The internet says 252 is the number "trading days" which must be Mon - Wed minus public holidays.  So probably users need to also subtract their 2 - 5 weeks of vacation.  On top of that.  So maybe 252 - 4 * 5 = 232 should be the default.  I guess it totally depends on your situation though.  I'll just leave it as is I guess.

[arebelspy]

Thanks Able!  I added a 'Working days per year' field and it defaults to 252.   Hmm now that I am doing some math I think the default should be closer to 240 or 230.  Meh.  The internet says 252 is the number "trading days" which must be Mon - Wed minus public holidays.  So probably users need to also subtract their 2 - 5 weeks of vacation.  On top of that.  So maybe 252 - 4 * 5 = 232 should be the default.  I guess it totally depends on your situation though.  I'll just leave it as is I guess.

Awesome.

I'd probably default to 242 or something with an explanation that it's 365 days - weekends - public holidays - 10 days vacation, and they can adjust for their own situation.

[Able was I ERE]

Thanks Able!  I added a 'Working days per year' field and it defaults to 252.   Hmm now that I am doing some math I think the default should be closer to 240 or 230.  Meh.  The internet says 252 is the number "trading days" which must be Mon - Wed minus public holidays.  So probably users need to also subtract their 2 - 5 weeks of vacation.  On top of that.  So maybe 252 - 4 * 5 = 232 should be the default.  I guess it totally depends on your situation though.  I'll just leave it as is I guess.

Awesome.

I'd probably default to 242 or something with an explanation that it's 365 days - weekends - public holidays - 10 days vacation, and they can adjust for their own situation.

Agreement on the awesomeness.  It's much closer to reality now.

And agreement that the default I suggested is probably not correct for most everyone----who has no vacation?  I think  ~2-4 weeks of vacation and 1-2 weeks of sick time is typical.  But, meh---the output is much closer to reality than it was before, so I'm not complaining.  (-;

[kablamo]

Thanks Able.  I just changed the default to 232 days.