Calculator guide
Project investment growth with regular monthly contributions. Use the explicitly labelled inputs below; rates, dimensions, and costs are assumptions, not live quotes.
Formula or method
Future value = P(1+r)^n + C((1+r)^n−1)÷r, where r = annual return ÷ 1200, n = years × 12, and C is an end-of-month contribution. At 0% return use P + C×n.
How to use this calculator
- Set Starting Balance. The interface starts with 10000; replace it with the value for your scenario.
- Set Annual Return (%). The interface starts with 7; replace it with the value for your scenario.
- Set Years to Grow (years). The interface starts with 20; replace it with the value for your scenario.
- Set Monthly Contribution. The interface starts with 200; replace it with the value for your scenario.
- Compare the result with the worked example, then vary one assumption at a time so you can see what changes.
Worked example
Enter Starting Balance = 10000; Annual Return = 7 %; Years to Grow = 20 years; Monthly Contribution = 200. With those assumptions, the calculator gives Future Value: $144,572.72; Total Contributions: $58,000.00; Interest Earned: $86,572.72. These outputs are calculated from the same implementation as the interactive tool.
Understanding the result
In this example, Future Value is $144,572.72. Total Contributions is $58,000.00. Estimates exclude charges and rules not represented by the inputs. Rates and prices are assumptions; results are not a quote or guaranteed return.
Limitations and assumptions
- Estimates exclude charges and rules not represented by the inputs. Rates and prices are assumptions; results are not a quote or guaranteed return.
- The worked example demonstrates the stated assumptions, not a recommendation about your personal circumstances.
Frequently asked questions
Which inputs should I check first?
For Compound Interest Calculator, check Starting Balance, Annual Return, Years to Grow, Monthly Contribution. Keep the displayed units and select options consistent; do not treat default values as recommendations.
Why might my result differ from another tool?
Compare the other tool's compound interest calculator method, input units, rounding and assumptions. A matching title does not guarantee that both tools answer the same question.
Does a linked reference certify this result?
No. A reference can explain a formula or provide background for Compound Interest Calculator, but it does not endorse this website, validate personal inputs or establish professional suitability.
Sources
Educational and planning information only. Sources are attributed background or formula references, not endorsements. Verify consequential decisions with an appropriate qualified professional.