{
  "id": "tdigest.rank",
  "title": "TDIGEST.RANK",
  "url": "https://redis.io/docs/latest/commands/tdigest.rank/",
  "summary": "Returns, for each floating-point input value, the estimated rank of the value (the number of observations in the sketch that are smaller than the value + half the number of observations that are equal to the value)",
  "tags": [
    "docs",
    "develop",
    "stack",
    "oss",
    "rs",
    "rc",
    "oss",
    "kubernetes",
    "clients"
  ],
  "last_updated": "2026-04-09T10:29:34-04:00",
  "page_type": "content",
  "content_hash": "c1dec25a0b8213d07beb4ee9e029d66d8991dc59c00217434915806618be56dd",
  "sections": [
    {
      "id": "overview",
      "title": "Overview",
      "role": "overview",
      "text": "Returns, for each floating-point input value, the estimated rank of the value (_the number of observations in the sketch that are smaller than the value_ + _half the number of observations that are equal to the value_).\nMultiple ranks can be retrieved in a single call."
    },
    {
      "id": "required-arguments",
      "title": "Required arguments",
      "role": "content",
      "text": "<details open><summary><code>key</code></summary>\n\nis the key name for an existing t-digest sketch.\n</details>\n\n<details open><summary><code>value</code></summary>\n\nis the input value for which the rank should be estimated.\n</details>"
    },
    {
      "id": "examples",
      "title": "Examples",
      "role": "example",
      "text": "redis> TDIGEST.CREATE s COMPRESSION 1000\nOK\nredis> TDIGEST.ADD s 10 20 30 40 50 60\nOK\nredis> TDIGEST.RANK s 0 10 20 30 40 50 60 70\n1) (integer) -1\n2) (integer) 0\n3) (integer) 1\n4) (integer) 2\n5) (integer) 3\n6) (integer) 4\n7) (integer) 5\n8) (integer) 6\nredis> TDIGEST.REVRANK s 0 10 20 30 40 50 60 70\n1) (integer) 6\n2) (integer) 5\n3) (integer) 4\n4) (integer) 3\n5) (integer) 2\n6) (integer) 1\n7) (integer) 0\n8) (integer) -1  \n\n  \n\nredis> TDIGEST.CREATE s COMPRESSION 1000\nOK\nredis> TDIGEST.ADD s 10 10 10 10 20 20\nOK\nredis> TDIGEST.RANK s 10 20\n1) (integer) 2\n2) (integer) 5\nredis> TDIGEST.REVRANK s 10 20\n1) (integer) 4\n2) (integer) 1"
    },
    {
      "id": "redis-software-and-redis-cloud-compatibility",
      "title": "Redis Software and Redis Cloud compatibility",
      "role": "content",
      "text": "| Redis<br />Software | Redis<br />Cloud | <span style=\"min-width: 9em; display: table-cell\">Notes</span> |\n|:----------------------|:-----------------|:------|\n| <span title=\"Supported\">&#x2705; Supported</span><br /> | <span title=\"Supported\"><nobr>&#x2705; Flexible & Annual</nobr></span><br /><span title=\"Supported\">&#x2705; Free & Fixed</nobr></span> |  |"
    },
    {
      "id": "return-information",
      "title": "Return information",
      "role": "returns",
      "text": "**RESP2:**\n\nOne of the following:\n\n* [Array]() of [integers]() populated with rank_1, rank_2, ..., rank_V:\n    * `-1` when `value` is smaller than the value of the smallest observation.\n    * The number of observations when `value` is larger than the value of the largest observation.\n    * Otherwise, an estimation of the number of (_observations smaller than `value`_ + _half the observations equal to `value`_).\n\n    `0` is the rank of the value of the smallest observation.\n\n    _n_-1 is the rank of the value of the largest observation, where _n_ denotes the number of observations added to the sketch.\n\n    All values are `-2` if the sketch is empty.\n* [Simple error reply]() in these cases: the given key does not exist or is of an incorrect type, quantile parsing errors, or incorrect number of arguments.\n\n**RESP3:**\n\nOne of the following:\n\n* [Array]() of [integers]() populated with rank_1, rank_2, ..., rank_V:\n    * `-1` when `value` is smaller than the value of the smallest observation.\n    * The number of observations when `value` is larger than the value of the largest observation.\n    * Otherwise, an estimation of the number of (_observations smaller than `value`_ + _half the observations equal to `value`_).\n\n    `0` is the rank of the value of the smallest observation.\n\n    _n_-1 is the rank of the value of the largest observation, where _n_ denotes the number of observations added to the sketch.\n\n    All values are `-2` if the sketch is empty.\n* [Simple error reply]() in these cases: the given key does not exist or is of an incorrect type, quantile parsing errors, or incorrect number of arguments."
    }
  ],
  "examples": []
}