Compound a storage footprint forward month by month and cost it at a blended hot and cold tier rate.
Storage growth compounds, so the arithmetic is a geometric series rather than a straight line: 4% a month is 60% a year, not 48%, and the cumulative bill is the sum of every intermediate month rather than the final month times the horizon. Applying a blended rate models the fact that lifecycle rules move a predictable share of the footprint to a cheaper tier as it ages. Both rates are user-supplied list prices to confirm on the AWS S3 pricing page for your region. Doubling time is the number that makes a growth rate feel real to a budget owner, and the cumulative figure is what a multi-year commitment or reserved capacity decision has to be justified against.
Cloud Storage Growth Forecast
size(month m) = base x (1 + rate)^m; doubling time = ln(2) ÷ ln(1 + rate); blended rate = hot rate x (1 − cold share) + cold rate x cold share.
size(month m) = base x (1 + rate)^m; doubling time = ln(2) ÷ ln(1 + rate); blended rate = hot rate x (1 − cold share) + cold rate x cold share. Storage growth compounds, so the arithmetic is a geometric series rather than a straight line: 4% a month is 60% a year, not 48%, and the cumulative bill is the sum of every intermediate month rather than the final month times the horizon. Applying a blended rate models the fact that lifecycle rules move a predictable share of the footprint to a cheaper tier as it ages. Both rates are user-supplied list prices to confirm on the AWS S3 pricing page for your region.
Doubling time is the number that makes a growth rate feel real to a budget owner, and the cumulative figure is what a multi-year commitment or reserved capacity decision has to be justified against.
This calculator takes 6 inputs: Data stored today, Monthly growth rate, Forecast horizon, Share that lifecycle rules move to a cold tier, Hot tier price, Cold tier price. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.
Because you pay for every month along the curve. The cumulative figure is a geometric sum, so over 24 months of 4% growth it lands near 16 times the first month's bill rather than 24 times it.