Compound Interest Calculator | Core Investing

📈 Core Investing · Compound Interest · Updates live as you type · Compare all compounding frequencies

Inputs

Your Investment Details

Starting Point

Initial Principal

$0 – $100,000

Monthly Contribution

$0 – $5,000/mo

Growth Parameters

Annual Interest Rate

S&P 500 avg ~10% nominal, ~7% real

Investment Period

1 – 60 years

Compounding Frequency

Compound Frequency (compare all in results below)

Try:

Results update live as you type

⚠️ Disclaimer & Notice

Results are estimates only. Not guarantees of any financial outcome.

Not financial, legal, tax, or investment advice. We are not a licensed advisor, lender, CPA, or attorney.

Rates, laws, and market conditions change. Investments can go up or down. Past performance does not guarantee future results.

Always consult a licensed professional before making financial decisions.

📌 Live Summary

Adjust inputs above — results update automatically.

💡 Compounding Tips

Rule of 72: Divide 72 by your rate to find how many years to double. At 7%, that's ~10.3 years.

Frequency: Daily compounding only beats annual by a small amount — it's the rate and time that matter most.

Starting amount: For long time horizons, consistent monthly contributions often matter more than a larger lump sum start.

Real vs nominal: Subtract ~3% inflation from your nominal rate to see your real purchasing power growth.

🔗 Related Calculators