CircleCI Gem Version Code Climate

Time Value of Money calculator

Performs financial calculations for:

  • n (number of periods)
  • pv (present value)
  • pmt (payment amount)
  • fv (future value)
  • i (interest rate)

NOTE: Only supports annuity due.


Install the gem:

gem install time_value

Initialize with values:

time_value =, i, pv, pmt, fv)

Or set values after initialization:

time_value =
time_value.n = my_n
time_value.i = my_i
time_value.pv = my_pv
time_value.pmt = my_pmt
my_fv = time_value.calc_fv()

Remember to follow a convention for signs of values:

  • Money being paid should have a negative value (-)
  • Money being received should have a positive value (+)

Failing to follow this convention may yield unexpected results