Estimate how much RAM your Redis dataset will use.
Per key
202 B
Estimated dataset
192.64 MB
With ~25% fragmentation
240.80 MB
These are rough estimates. Actual Redis memory depends on version, internal encoding (ziplist/listpack vs hashtable), and allocator rounding. Always confirm against INFO memory and MEMORY USAGE on a real instance before capacity planning.
Enter your key count, key and value sizes, and data type to estimate how much memory Redis will need. The estimate includes the per-key overhead Redis adds — the dictionary entry, the value wrapper, and SDS string headers — which dominates memory when you store millions of small keys.
Collection types (hashes, lists, sets, sorted sets) cost more per element than a plain string, and sorted sets cost the most because each member also stores a score and skiplist pointers. Treat the result as a planning estimate: real usage depends on your Redis version, internal encoding, and allocator, so always confirm with `INFO memory` on a real instance.
Because every key carries overhead beyond its value: a hash-table entry, a value wrapper object, and string headers — often 50–100 bytes per key. With many small keys this overhead can exceed the data itself, which is why per-key cost matters more than value size at scale.
It is a rough planning figure, not an exact number. Actual memory depends on your Redis version, whether small collections use the compact listpack encoding, and jemalloc rounding. Always validate against `INFO memory` and `MEMORY USAGE key` on a real instance before sizing hardware.