Compound Interest Calculator

Initial Investment ($) Monthly Contribution ($) Average Interest Rate (%) Length of Time (Years)

Withdrawal Planning (optional)

Model up to 10 withdrawals at any points in your timeline. Leave any slot blank to skip it.

Opportunity Cost (optional)

"If I spent this instead of investing it" — shown as what it would have grown to by the end of your timeline, invested today at your rate above.

Unnecessary Purchase Amount ($)