Savings annuity calculator with graph help


Settings Remark
Days in year The number of days within a year can be set to:
  • 366 days
    This is a leap year (normal year + 1 day extra (29 feb)

  • 365 days
    Normal year (non leap year)

  • 364 days
    The 364 day year derives from 52 weeks * 7 day weeks = 364 days in a year.

  • 360 days
    When a month has 30 days, a year has 12 months * 30 = 360 days
The nominal interest rate (R) is specified per year.
The number of days within a year is important when adjusting the time period especially when the day unit is used.

Example 1: How time period will be adjusted, a year has 366 days:
Interest rate = 5% per year
Time period = 100 days

366 days equals 1 year
Thus 100 days equals 100/366 = 0.273224 days

Example 2: How time period will be adjusted, a year has 365 days:
Interest rate = 5% per day
Time period = 100 days

365 days equals 1 year
Thus 100 days equals 100/365 = 0.273973 days

Example 3: How time period will be adjusted, a year has 364 days:
Interest rate = 5% per day
Time period = 100 days

364 days equals 1 year
Thus 100 days equals 100/364 = 0.274725 days

Example 4: How time period will be adjusted, a year has 360 days:
Interest rate = 5% per day
Time period = 100 days

360 days equals 1 year
Thus 100 days equals 100/360 = 0.277778 days