[the_fire_friar]

Love these formulas and wish this information was more understood and accessible to people when making decisions. I've personally benefited a lot from a mortgage payoff spreadsheet I have. It's so easy to duplicate a tab, change the interest rate or additional payments and see what the long term impact is.

That being said, and a disclaimer that I created this, I have been charting my path to being able to retire early. I found it difficult when duplicating tabs to simulate different scenarios and keeping the tabs up-to-date with formula changes. If this speaks to any of you, then consider checking out the tool I made - I have not looked back at my old spreadsheets.

Sample forecast: https://fiers.co/forecast/6020f254b4e8c

Forecast comparison: https://fiers.co/forecasts/compare/6020f254b4e8c/60488472528...

[phonon]

Have you looked at the "What-if Analysis" functionality in Excel? Scenario Manager and Data Table is designed for that kind of use case (one set of formulas, multiple sets of inputs/scenarios.)

Here are some videos on how to use them.

Data Table https://www.youtube.com/watch?v=y7S9ecg1wdQ

Scenario Manager https://www.youtube.com/watch?v=b_eFIdsV1Bk

[the_fire_friar]

Those are really cool. I didn't know about them (I was also using Google Sheets :|).

Perhaps because I'm comfortable writing software it still feels very limiting to work within spreadsheets.

[Terretta]

Think of spreadsheets as an IDE for functional programming so your brain treats them as software.

Arguably, the more code works like a spreadsheet (functions transforming values, lists, or matrices) rather than stepwise ‘if this then that’ sequences, the better.

Put another way, logic can be woolier than math, in that concise mathematical formulation tends to removes ambiguity when reasoning over inputs to generate outputs.