Invest Ksh 500,000 at Development Bank of Kenya for 20 years.
At Development Bank of Kenya's current weighted-average deposit rate of 10.83%, a Ksh 500,000 deposit grows to about Ksh 4,319,489 after 20 years — about Ksh 3,819,489 in interest, assuming monthly compounding and no withdrawals.
Final balance
Ksh 4,319,489
8.64× your deposit
Deposited
Ksh 500,000
One-off, no withdrawals
Interest earned
Ksh 3,819,489
At 10.83% p.a.
Year by year
Contributions form the floor; interest compounds on top.
Could you earn more elsewhere?
The same Ksh 500,000 in Cytonn Money Market Fund — currently Kenya's top-yielding MMF at 9.39% net of 15% WHT — would grow to about Ksh 3,246,389 over the same 20 years. Run your own numbers on the compound interest calculator.