# [Sherri Wheeler]

Web developer, problem solver, mom, gamer, builder of forts, & maker in training.

## Savings Timeframe Calculator

How long to reach a given savings target. (Scroll down for help.)

 Yearly Interest Rate (%) Initial Balance Monthly Contribution Target Final Balance

Results:
Approximate time until savings goal is reached (nper):

 Years Months

## Legend

Interest Rate
The yearly interest rate you will earn. Assumes monthly compounding (like a savings account).
Initial Balance
Monthly Contribution
Amount you will contribute monthly to the account. Enter zero for none.
Final Balance
The total amount of funds you want to end up with.

This financial math calculator is the Time Value of Money annuity formula solved for n (number of months). Similar to Excel's nper formula.

```Formula:
n = log( (i*FV+PMT)/(i*PV+PMT) )
-----------------------
log (i + 1)
```
Where:
n = number of months
i = monthly interest rate as a decimal (ex 4% annual use: 4/1200)
FV = future value of annuity
PV = present value of annuity
PMT = amount of each monthly payments