Quick answer: 1,000 today plus 100 at the end of each period, at 5% a period for 10 periods, has a future value of 2,886.68 (1,628.89 from the 1,000 and 1,257.79 from the payments).
How it's calculated
FV = PV(1 + i)^n + PMT × ((1 + i)^n − 1) ÷ i, where i is the rate per period and n the number of periods. For payments at the start of each period (an annuity due), the payment part is multiplied by (1 + i).
Keep the rate and the periods in the same unit: for monthly periods use the annual rate ÷ 12 and the number of months. The result matches the spreadsheet FV function.
To go the other way – what a future amount is worth today – use the present value calculator; to solve any of the five values, use the financial calculator.
Worked examples
- 1,000 at 5% for 10 periods: 1,000 × 1.05^10 = 1,628.89
- 100 at the end of each of 10 periods at 5%: 100 × (1.05^10 − 1) ÷ 0.05 = 1,257.79
Frequently asked questions
What is a period?
Any equal interval – a year, a quarter, a month. The rate must be for the same interval.
Can the rate be negative?
Yes, down to −99%, for example to see the effect of a value that falls each period.
How is this different from compound interest?
It is the same maths, written per period so it fits any timing. The compound interest calculator works in years with monthly deposits.
How do I use a monthly rate?
Divide the annual rate by 12 and count the periods in months. 6% a year for 5 years is 0.5% a period for 60 periods.
Why is a start-of-period payment worth more?
Each payment earns for one extra period, so the payment part is multiplied by (1 + the rate).
Does the future value allow for inflation?
No. It is in future money. To see what it would buy today, take the result to the present value calculator using the inflation rate.