Here are the monthly interest for exactly $60k monthly average effective balance deposit in BOC SmartSaver a/c:
Prevailing Interest (0.4%) - $60,000 * (0.004/365*no. of days)
refer BOC website for tiered prevailing interest rate:
http://www.bankofchina.com/sg/bocinfo/bi3/201002/t20100207_961728.html
Calendar month with 30 days=$19.73
Calendar month with 31 days=$20.38
[note: there is no cap on the daily balance which gets Prevailing interest. Prevailing interest is accrued daily & credited at the end of each month. The calculation is simple if you have $60k daily balance throughout the entire month, but it gets a little more complicated if the daily balances fluctuate throughout the month]
3 Bill Payment Bonus Interest (0.35%) - $60,000 * (0.0035/365*no. of days)
Calendar month with 30 days=$17.26
Calendar month with 31 days=$17.84
Salary $2k Bonus Interest (0.8%) - $60,000 * (0.008/365*no. of days)
Calendar month with 30 days=$39.45
Calendar month with 31 days=$40.77
Salary $6k Bonus Interest (1.2%) - $60,000 * (0.012/365*no. of days)
Calendar month with 30 days=$59.18
Calendar month with 31 days=$61.15
Credit/Debit Card spent $500 Bonus Interest (0.8%) - $60,000 * (0.008/365*no. of days)
Calendar month with 30 days=$39.45
Calendar month with 31 days=$40.77
Credit/Debit Card spent $1,500 Bonus Interest (1.6%) - $60,000 * (0.016/365*no. of days)
Calendar month with 30 days=$78.90
Calendar month with 31 days=$81.53
Extra Savings Interest - Enjoy 0.60% p.a. Extra bonus interest when you have fulfilled at least one of the requirements for either Card Spend, Salary Crediting or Payment bonus interest. Payment bonus is applicable to your account balance above S$60k subject to a maximum of S$1m
Example – Calendar month of 31 days :
Prevailing interest =$20.38
Meet 3 bill payment => $17.84
If have Salary $6k => $61.15
If credit card spent $1,500 => $81.53
Total Bonus interest = $160.52
Total interest = $180.90 (include Prevailing interest)