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Compound Interest & Future Value Calculator

Project future value from a starting balance, recurring contributions, growth rate and compounding period.

Private by design. Inputs and calculations stay in this browser tab. No financial or property values are uploaded.

Scenario inputs

Compound Interest Calculator

The model compounds monthly and adds the recurring contribution at the end of each month.

Calculated view
Future value$300,850.72
Total contributions$130,000.00
Growth$170,850.72
Growth share56.79%
Sensitivity analysis

Scenario lab

Changes only Annual growth rate while holding the other assumptions constant.

80% input5.6
Primary result: 250,948.79
90% input6.3
Primary result: 274,549.73
100% input7
Primary result: 300,850.72
110% input7.7
Primary result: 330,185.64
120% input8.4
Primary result: 362,931.35

This calculator is an educational planning tool. Verify financing, tax, legal, investment and accounting decisions using the authoritative documents and professionals that apply to your situation.

Why this tool is different

Project future value from a starting balance, recurring contributions, growth rate and compounding period. OpenFileTools exposes the inputs, formulas and scenario effects so the estimate remains auditable.

Requirements and recommendations

Model the decision with explicit assumptions

  • Enter realistic assumptions instead of best-case values.
  • Use the scenario lab to see which assumption changes the result most.
  • Verify taxes, rates, fees, legal rules and market inputs from authoritative sources before making a real decision.
How OpenFileTools processes it

Local processing, explicit choices.

The browser evaluates the published calculation from your inputs and recomputes a bounded sensitivity range around the selected scenario variable. No external market feed or hidden scoring service is called.

Frequently asked

Questions, answered.

Is my data uploaded?

No. Batch 3 workbooks, trackers and calculators run locally in this browser tab and generate downloads on your device.

Are the results official advice?

No. These tools are planning and analysis aids. Verify important academic, financial, tax, legal, lending, employment or investment decisions with the relevant authoritative source or professional.

Related guide

Learn more about this task.

Read the related guide