Investment Calculator Question

[jnw]

Do these calculators take into consideration your monthly contribution to this investment will increase along with the rate of inflation?   Like next year I'll have 7% more income due to inflation, so I will be contributing perhaps 7% more each year -- year over year according to rate of inflation.

Average inflation rate is 4% over the last 100 years right?  So do these calculators assume you'll be adding in 4% more each year compared to previous year -- on average.

[MDM]

You'll need to define "these" as in "these calculators."

It is not uncommon for calculations to be done in "today's dollars" using "real returns" - in other words, ignoring inflation effects on contributions, investment growth, and spending needs.