FIRE calculator: how many years until you can retire?

[Ryan Kuck]

This free app let's you quickly determine when you can retire, is it just me or is this really useful? Anyone know of better apps you like for this or what you like to do for your personal calculations different from this?

[Steve Vaughan]

@Ryan Kuck I'm too old to do much with apps, but the key for me going FI so long ago was minding my gap.  The gap is what you keep above what you need.  

The gap changes most as we reduce our expenses.  Increasing the size of your shovel (income) is fine though costly tax-wise if its earned income, but keep your eye on the hole (outflows).

Not sure if your app tells you or adjusts when mortgages are paid off, but that was key for me.  Having a 'luxury' househack (pays all our housing costs+ but isn't a traditional plex), paying off all non-conventional mortgages and not having car payments ever were key for me.  

My skinny FI gap was 1.5x keep or savings rate above expenses initially, then grew from there as mortgages fell off.

It wasn't an income thing, evidenced by not paying into social insecurity since 2002. I did it by learning how to do high dollar tasks normal people pay for, myself.