Redshift Storage Calculator
Project Redshift storage after columnar compression and growth, and compare RA3 managed storage against DC2 local capacity.
Inputs
AZ64 and ZSTD encodings typically deliver 3x to 4x on warehouse data.
dc2.large offers 0.16 TB, dc2.8xlarge offers 2.56 TB.
Projected Compressed Size
11.20TB
Compressed Size Today
5.71TB
Projected Compressed Size
11 TiB
RA3 Managed Storage Cost
$275.25
DC2 Nodes Needed for Capacity
5nodes
Storage Model
RA3 decouples storage from compute — size the cluster for query concurrency and pay for storage separately
Step by step
Values used
Raw uncompressed data = 20 TB; Columnar compression ratio = 3.50 x; Annual data growth = 40 %; Plan ahead = 2 years; Node family = RA3 — managed storage billed separately; RA3 managed storage price = 0.0240 $/GB-month; DC2 storage per node = 2.56 TB
Redshift Storage
compressed = raw ÷ compression ratio; projected = compressed × (1 + annual growth)^years; DC2 nodes = ceil(projected TB ÷ TB per node).
Projected Compressed Size
= 11.20 TB
Compressed Size Today
= 5.71 TB
Projected Compressed Size
= 12,314,530,231,091
RA3 Managed Storage Cost
= 275.25
DC2 Nodes Needed for Capacity
= 5 nodes
Storage Model
= RA3 decouples storage from compute — size the cluster for query concurrency and pay for storage separately
How it works
Redshift stores data column by column and encodes each column separately, so 3x to 4x compression is normal and the raw figure badly overstates what you pay for. On RA3 that compressed volume is billed as managed storage at a flat GB-month rate and the node count is driven purely by query concurrency, whereas on DC2 the local SSD is bundled into the node and capacity alone can force nodes you do not need for compute. The managed-storage rate is an editable input with a realistic us-east-1 default — confirm current Redshift prices with AWS for your region. The RA3 versus DC2 decision is usually settled by this arithmetic: once capacity rather than concurrency dictates the DC2 node count, RA3 with separately billed managed storage is almost always cheaper.
Formula
Redshift Storage
compressed = raw ÷ compression ratio; projected = compressed × (1 + annual growth)^years; DC2 nodes = ceil(projected TB ÷ TB per node).
- compression ratio
- Raw bytes divided by stored bytes after column encoding
- RA3 managed storage
- S3-backed storage billed per GB-month, independent of node count
- DC2 local storage
- SSD attached to the node — capacity and compute scale together
Frequently Asked Questions
How is Redshift Storage calculated?
compressed = raw ÷ compression ratio; projected = compressed × (1 + annual growth)^years; DC2 nodes = ceil(projected TB ÷ TB per node). Redshift stores data column by column and encodes each column separately, so 3x to 4x compression is normal and the raw figure badly overstates what you pay for. On RA3 that compressed volume is billed as managed storage at a flat GB-month rate and the node count is driven purely by query concurrency, whereas on DC2 the local SSD is bundled into the node and capacity alone can force nodes you do not need for compute. The managed-storage rate is an editable input with a realistic us-east-1 default — confirm current Redshift prices with AWS for your region.
Why does Redshift Storage matter?
The RA3 versus DC2 decision is usually settled by this arithmetic: once capacity rather than concurrency dictates the DC2 node count, RA3 with separately billed managed storage is almost always cheaper.
What values do I need to enter?
This calculator takes 7 inputs: Raw uncompressed data, Columnar compression ratio, Annual data growth, Plan ahead, Node family, RA3 managed storage price, DC2 storage per node. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.
What compression ratio should I assume?
Run ANALYZE COMPRESSION on a representative table rather than guessing. Wide fact tables with low-cardinality columns often exceed 4x, while pre-compressed or high-entropy data such as hashes and encrypted blobs may barely compress at all.