Continuous compounding
Continuous compounding is the limiting case of compound interest where interest accrues at every instant, so future value equals present value multiplied by e to the power of the rate times time.
See it move
Marta invests €5,000 at a 6% annual rate for four years. Compounded once a year, it grows to €5,000 × 1.06⁴ = €6,312.38. Compounded continuously, using e^(rt), it grows to €5,000 × e^0.24 = €6,356.25 — €43.87 more, because interest accrues at every instant rather than once a year.
The formula
Variables
- Future value (€)
- Present value (€)
- Euler's number, approximately 2.71828 (dimensionless)
- Annual continuously compounded rate (decimal)
- Time (years)
Gives the future value of an amount growing at a continuously compounded annual rate over time t, measured in years.
Variables
- Equivalent effective annual rate (decimal)
- Euler's number, approximately 2.71828 (dimensionless)
- Annual continuously compounded rate (decimal)
Converts a continuously compounded rate into the effective annual rate it is equivalent to under ordinary once-a-year compounding.
Check yourself
An investment of €8,000 earns interest at a continuously compounded annual rate of 5%. Using e ≈ 2.71828, what is its value after 3 years?