Finance

Compound Interest Calculator

Forecast investment growth with compounding and recurring contributions.

Last validated: 2026-02-14

Compound Interest Calculator projects future balance growth with compounding and optional periodic contributions. It is useful for savings goals, retirement planning, and investment scenario comparisons. The tool makes time and rate effects easy to visualize. Use it to evaluate disciplined contribution strategies.

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Input Pattern

Enter values in the left panel, keep units explicit, run the calculation, then copy or share the result. Invalid fields are highlighted immediately.

Compound Interest Solver

Estimate future value with recurring yearly contributions.

Results

Future value: $20,096.61
Total contributions: $10,000.00
Interest earned: $10,096.61

How to use this tool

Enter initial amount, interest rate, compounding frequency, and duration.
Add periodic contribution values if applicable, then run calculation.
Compare scenarios with different rates and contribution schedules.

Worked Example

Auto-generated from the tool's current default or entered inputs.

Example Inputs

Principal: 10000.0
Annual rate percent: 7.0
Years: 10.0
Compounds per year: 12.0
Annual contribution: 0.0
Future value: 20096.613766956318
Annualized return amount: 7.229008085623589

Expected Outputs

Principal: 10000
Annual rate percent: 7
Years: 10
Compounds per year: 12

Interpretation

Principal is 10000.0. Use this as a decision input, not as a standalone conclusion.
Annual rate percent is 7.0. Use this as a decision input, not as a standalone conclusion.
Years is 10.0. Use this as a decision input, not as a standalone conclusion.
Compare at least one conservative and one aggressive scenario before committing to a target.

Scenario Compare (A vs B)

Use this to compare two input sets and quantify change in key outputs.

Scenario A

Principal

Annual rate percent

Years

Compounds per year

Annual contribution

Future value

Annualized return amount

Scenario B