elasticsearch/docs/reference/aggregations/search-aggregations-metrics-max-aggregation.md
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---
navigation_title: "Max"
mapped_pages:
- https://www.elastic.co/guide/en/elasticsearch/reference/current/search-aggregations-metrics-max-aggregation.html
---
# Max aggregation [search-aggregations-metrics-max-aggregation]
A `single-value` metrics aggregation that keeps track and returns the maximum value among the numeric values extracted from the aggregated documents.
::::{note}
The `min` and `max` aggregation operate on the `double` representation of the data. As a consequence, the result may be approximate when running on longs whose absolute value is greater than `2^53`.
::::
Computing the max price value across all documents
```console
POST /sales/_search?size=0
{
"aggs": {
"max_price": { "max": { "field": "price" } }
}
}
```
Response:
```console-result
{
...
"aggregations": {
"max_price": {
"value": 200.0
}
}
}
```
As can be seen, the name of the aggregation (`max_price` above) also serves as the key by which the aggregation result can be retrieved from the returned response.
## Script [_script_6]
If you need to get the `max` of something more complex than a single field, run an aggregation on a [runtime field](docs-content://manage-data/data-store/mapping/runtime-fields.md).
```console
POST /sales/_search
{
"size": 0,
"runtime_mappings": {
"price.adjusted": {
"type": "double",
"script": """
double price = doc['price'].value;
if (doc['promoted'].value) {
price *= 0.8;
}
emit(price);
"""
}
},
"aggs": {
"max_price": {
"max": { "field": "price.adjusted" }
}
}
}
```
## Missing value [_missing_value_10]
The `missing` parameter defines how documents that are missing a value should be treated. By default they will be ignored but it is also possible to treat them as if they had a value.
```console
POST /sales/_search
{
"aggs" : {
"grade_max" : {
"max" : {
"field" : "grade",
"missing": 10 <1>
}
}
}
}
```
1. Documents without a value in the `grade` field will fall into the same bucket as documents that have the value `10`.
## Histogram fields [search-aggregations-metrics-max-aggregation-histogram-fields]
When `max` is computed on [histogram fields](/reference/elasticsearch/mapping-reference/histogram.md), the result of the aggregation is the maximum of all elements in the `values` array. Note, that the `counts` array of the histogram is ignored.
For example, for the following index that stores pre-aggregated histograms with latency metrics for different networks:
```console
PUT metrics_index
{
"mappings": {
"properties": {
"latency_histo": { "type": "histogram" }
}
}
}
PUT metrics_index/_doc/1?refresh
{
"network.name" : "net-1",
"latency_histo" : {
"values" : [0.1, 0.2, 0.3, 0.4, 0.5],
"counts" : [3, 7, 23, 12, 6]
}
}
PUT metrics_index/_doc/2?refresh
{
"network.name" : "net-2",
"latency_histo" : {
"values" : [0.1, 0.2, 0.3, 0.4, 0.5],
"counts" : [8, 17, 8, 7, 6]
}
}
POST /metrics_index/_search?size=0&filter_path=aggregations
{
"aggs" : {
"max_latency" : { "max" : { "field" : "latency_histo" } }
}
}
```
The `max` aggregation will return the maximum value of all histogram fields:
```console-result
{
"aggregations": {
"max_latency": {
"value": 0.5
}
}
}
```