Compound Interest & Real Future Value
This calculator estimates how a lump sum and regular monthly contributions could grow over time when interest is compounded monthly. Each month, interest is applied to the total balance, which includes your starting amount, any contributions made so far, and any one-off lump sum added at your chosen point. The calculator also shows what your projected balance might be worth in today's money by applying an inflation adjustment over the full investment period.
Calculator Assumptions
Interest is compounded monthly, not annually.
Monthly contributions are assumed to be made consistently every month for the full term.
Any one-off lump sum is added at the exact month you specify and then compounded for the remaining period.
If a 0% interest rate is entered, growth is calculated as simple addition (no compounding effect applied).
The annual interest rate you enter is divided equally across 12 months.
Inflation is assumed to remain constant at the rate you enter, applied annually over the full term.
Calculator Limitations
This calculator provides illustrative projections only and does not constitute financial advice.
Results assume a fixed, constant rate of return, real investment returns will vary and are not guaranteed.
The calculator does not account for taxes, fees, charges, or changes in contribution amounts over time.
Inflation figures are illustrative; actual inflation will fluctuate and may differ significantly.
Lump sum timing is simplified to a single injection at one point in time, partial or staggered payments are not supported.
This tool is intended for general information purposes only. You should seek independent financial advice before making any investment decisions.
Privacy & Data Security
All calculations are executed locally within your browser. We do not track, store, or monitor the figures you enter into this tool.