Time until target met

[LinkOps]

Hi,

I currently need to discover how long until a disk will become full based around 10% annual growth of the current data. I currently have the current data size and the remaining available space.

Used Space: 238323
Available Space: 314368

I need to know how many years growth is remaining at 10% growth per year of the used space. The used space should grow year on year and the result should tell me how many years until complete.

I would ideally like to do this in a single formula without having to add multiple arrays of data to calculate it.

Many Thanks,

Marcus

[jhren]

B1 = Used Space (text in A1)
B2 = Available Space (text in A2)
B3 = Annual Growth Rate (text in A3)
A4 --> Years Remaining
B4 --> =ROUNDDOWN(LN((B1+B2)/B1)/LN(1+B3),0)

Answer should be 8 (years).

Remove the ROUNDDOWN function if you want answer in decimal rather than whole years.