Project compound plus flat database growth, find the doubling time and the month the allocated storage runs out.
Real databases grow two ways at once, so the projection combines a geometric term for size-proportional growth with an annuity term for the fixed monthly feed. Doubling time comes from the compound rate alone and is the figure worth remembering: 6% a month doubles the database in under a year, which is why linear extrapolation from a single month always under-predicts. The storage rate is an editable input with a realistic us-east-1 default, so confirm the current price with AWS for your region. Storage runway is the input to the only two decisions that matter here — when to grow the volume and when to start archiving — and both need lead time measured in months, not the week before the volume fills.
Database Growth
size after m months = current × (1 + r)^m + flat × ((1 + r)^m − 1) ÷ r; doubling time = ln(2) ÷ ln(1 + r).
size after m months = current × (1 + r)^m + flat × ((1 + r)^m − 1) ÷ r; doubling time = ln(2) ÷ ln(1 + r). Real databases grow two ways at once, so the projection combines a geometric term for size-proportional growth with an annuity term for the fixed monthly feed. Doubling time comes from the compound rate alone and is the figure worth remembering: 6% a month doubles the database in under a year, which is why linear extrapolation from a single month always under-predicts. The storage rate is an editable input with a realistic us-east-1 default, so confirm the current price with AWS for your region.
Storage runway is the input to the only two decisions that matter here — when to grow the volume and when to start archiving — and both need lead time measured in months, not the week before the volume fills.
This calculator takes 6 inputs: Current database size, Compound monthly growth, Flat monthly additions, Allocated storage, Project ahead, Storage 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.
A fixed monthly addition also compounds once it lands, because next month's percentage growth applies to it too. The annuity term ((1 + r)^m − 1) ÷ r accumulates each deposit with the growth it earns after arriving, which simple multiplication misses.