The Time Diagram

The horizontal line represents time, measured in periods (typically years). Each tick mark is a point in time. Cash flows- amounts of money received or paid- appear above each unit of time as a value you can edit. Click any tick to designate it as your valuation point; the calculator will show the value of all cash flows at that point in time.

Interest Rate (i) and n

i is the annual effective interest rate: the rate at which money grows over one period. A dollar today is worth more than a dollar a year from now because you can invest that dollar today and earn interest on it — this is the time value of money.

n is the total number of time periods on the diagram. Increase it to model longer horizons.

Calculator Modes

• Individual Payments: Enter any cash flow at any point, model how single or multiple individual payments grow over time.
• Annuities: A sequence of equal (level), evenly-spaced payments. Set the payment amount, the start period, and end period to see what the sequence of payments is worth over time.
• Loans: Models a level-payment amortizing loan. Provide the loan amount and term; the calculator will derive the equal periodic payments to pay off the loan in a fixed interval of time.
• Bonds: A bond pays periodic coupons plus its face value at maturity. Enter the face value, coupon rate, and desired yield to see how the bond's price evolves over time.

Game Mode

Test your understanding with randomly generated, exam-style multiple-choice problems drawn from all four topics. All questions can be solved directly using the calculator. After selecting an answer, a complete step-by-step solution is shown in standard actuarial notation. Use the Formulas button for a concise reference sheet, and New Question to move on.

The Reset Button (↺)

Resets the current mode's parameters to their defaults without changing the number of periods n. In Individual Payments mode, it zeros all cash flows so you can start fresh.