Tool: Compound interest calculator · Embed · All how-we-calculate pages · Questions
Purpose
Estimate future value of a starting principal (and optional monthly deposits) under a constant annual rate and compounding choice. Educational only.
Principal-only formulas
- Discrete:
A = P(1 + r/n)^(n·t) - Continuous:
A = P·e^(r·t) -
Effective annual yield (discrete):
(1 + r/n)^n − 1; continuous:e^r − 1
Monthly deposits (educational)
Optional deposits use an ordinary annuity style model with monthly rate r/12 and number of months
from years × 12. Year tables step monthly interest then deposit for a readable schedule.
What we intentionally leave out
- Fees, taxes, inflation adjustment, and market volatility
- Live rates or product recommendations
- Variable returns and sequence-of-returns risk
Related
Last reviewed: August 9, 2026.
YMYL notice: This site is for education only. It is not financial, tax, or investment advice. Nestfigure is not a bank, credit union, broker, investment adviser, or fiduciary. Product terms, rates, and penalties vary—always read your institution’s disclosures before acting. Calculator results are mathematical estimates, not bank quotes.