Retirement planning with inflation & monthly contributions
Building a retirement nest egg requires understanding two powerful forces: compound growth and inflation. This calculator projects your future savings while adjusting for the eroding effect of inflation. The real rate of return (nominal return minus inflation) shows your true increase in purchasing power. For most US citizens aged 40+, consistently investing a monthly amount can dramatically improve retirement readiness.
Why monthly contributions matter
Even modest monthly contributions add up. In our example (40 years old, retiring at 65, $50k current savings, $500/month, 7% return, 3% inflation), the inflation‑adjusted future value is about $892,000 — significantly less than the nominal $1.23M, but still a solid foundation. Without monthly contributions, that figure would be only around $270k (in today's dollars).
Understanding the formulas
We use the future value of a series formula: FV = P × ((1+r)ⁿ − 1)/r for monthly contributions, plus compound growth on current savings. Inflation adjustment: Real = FV / (1+inflation)ⁿ. The real return is derived from (1+nominal)/(1+inflation) − 1.
Impact of inflation: At 3% inflation, prices double about every 24 years. That's why we must target returns above inflation. Our calculator gives you a realistic view.