What does a yearly step-up add?

Incomes rise. An SIP that rises with them is the one habit that is a plan rather than a nerve, and the cheapest fix on the whole site.

Starting instalment, every month Raise it every year by, % Years Expected growth, % a year

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Flat SIP, at the end
Stepped-up SIP, at the end
Extra you put in

Growth is assumed steady, which markets never are; the point is the size of the effect, not the exact number. The simulator applies a step-up to real NAV history if you want the messy version.