Home › Calculators › Compound interest calculator › 1000-15y-8
$1,000 invested for 15 years at 8%
Exact compound math for the given inputs.
$3,306.92
future value (monthly compounding, no deposits)
Principal$1,000.00
Interest earned$2,306.92
Growth multiple3.31×
Rule of 729.0 yrs to double
Frequently asked questions
How much will $1,000 be worth in 15 years at 8%?
With monthly compounding it grows to $3,306.92 — that is $2,306.92 of interest earned on $1,000.00.
What if compounding is annual instead of monthly?
Annual compounding gives $3,172.17 — more frequent compounding always yields slightly more.
How long until it doubles?
The Rule of 72 estimates 9.0 years at 8% (9.00 precisely).
Try nearby scenarios
Change the numbers yourself
Open the interactive compound interest calculator — every field is editable.