Compound Interest Calculator
Calculate compound interest growth on initial deposits and recurring contributions with custom compounding intervals.
Computes future value using FV = P(1 + r/n)^(nt) + PMT * [((1 + r/n)^(nt) - 1) / (r/n)].
Input Parameters & Sliders
Calculation Summary
Verified ResultScenario Comparison Matrix (Scenario A vs Scenario B)
Visual Growth & Cost Trajectory
Period Schedule & Amortization Table
| Year / Period | Principal / Contrib | Interest / Earned | Ending Balance |
|---|---|---|---|
Model Assumptions & Constraints
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Formula & Mathematical Methodology
This calculation executes active immutable formula specification 1.0.0.
Step-by-Step Worked Example
10-Year Growth on $10,000 Initial + $500 Monthly at 7%
STEP1: Initial investment of $10,000 accumulates interest compounding monthly.
STEP2: Monthly deposits of $500 add $60,000 over 120 months, totaling $70,000 invested.
STEP3: At a 7% annual interest rate, compounding yields $37,143.85 in cumulative interest earned, bringing total balance to $107,143.85.
Authoritative Sources & Method Evidence
Every formula calculation, tax bracket, cutoff metric, and assumption in this model is mapped directly to authoritative primary sources and regulatory literature.
Federal Reserve Board of Governors: Consumer Financial Protection Bureau (CFPB) Loan & Interest Standards
Formula matches SEC & CFPB standard financial compound interest models.
Frequently Asked Questions
How does compounding frequency impact investment growth?
More frequent compounding intervals (e.g., monthly vs. annually) allow interest earned in earlier periods to generate additional interest sooner, resulting in a higher effective annual yield (APY).