diff --git a/docs/content/guides/js-marker-clusterer/markers-cluster-with-js-marker-clusterer.md b/docs/content/guides/js-marker-clusterer/markers-cluster-with-js-marker-clusterer.md
index 21beb35da..6a0c58660 100644
--- a/docs/content/guides/js-marker-clusterer/markers-cluster-with-js-marker-clusterer.md
+++ b/docs/content/guides/js-marker-clusterer/markers-cluster-with-js-marker-clusterer.md
@@ -53,4 +53,16 @@ When you import the `AgmJsMarkerClustererModule`, you can use the `agmMarkerClus
     <agm-marker *ngFor="let marker of markers" [latitude]="marker.latitude" [longitude]="marker.longitude"></agm-marker>
   </agm-marker-cluster>
 </agm-map>
-```
\ No newline at end of file
+```
+
+### Specifying a custom calculator
+
+If you want to control how the cluster style is calculated, you can pass in a `CalculateFunction` via `calculator`:
+
+```html
+<agm-map [latitude]="0" [longitude]="0">
+  <agm-marker-cluster [calculator]="myCalculatorFn">
+    <agm-marker *ngFor="let marker of markers" [latitude]="marker.latitude" [longitude]="marker.longitude"></agm-marker>
+  </agm-marker-cluster>
+</agm-map>
+```
diff --git a/packages/js-marker-clusterer/directives/marker-cluster.ts b/packages/js-marker-clusterer/directives/marker-cluster.ts
index 7af0be6a1..767ed33e8 100644
--- a/packages/js-marker-clusterer/directives/marker-cluster.ts
+++ b/packages/js-marker-clusterer/directives/marker-cluster.ts
@@ -3,7 +3,7 @@ import {Directive, Input, OnDestroy, OnChanges, OnInit, SimpleChange} from '@ang
 import {ClusterManager} from '../services/managers/cluster-manager';
 import {MarkerManager, InfoWindowManager} from '@agm/core';
 
-import {ClusterOptions, ClusterStyle} from '../services/google-clusterer-types';
+import {CalculateFunction, ClusterOptions, ClusterStyle} from '../services/google-clusterer-types';
 
 /**
  * AgmMarkerCluster clusters map marker if they are near together
@@ -71,6 +71,11 @@ export class AgmMarkerCluster implements OnDestroy, OnChanges, OnInit, ClusterOp
    */
   @Input() styles: ClusterStyle;
 
+  /**
+   * A function that calculates the cluster style and text based on the markers in the cluster.
+   */
+  @Input() calculator: CalculateFunction;
+
   @Input() imagePath: string;
   @Input() imageExtension: string;
 
@@ -110,6 +115,9 @@ export class AgmMarkerCluster implements OnDestroy, OnChanges, OnInit, ClusterOp
     if (changes['imageExtension']) {
       this._clusterManager.setImageExtension(this);
     }
+    if (changes['calculator']) {
+      this._clusterManager.setCalculator(this);
+    }
   }
 
   /** @internal */
diff --git a/packages/js-marker-clusterer/services/managers/cluster-manager.spec.ts b/packages/js-marker-clusterer/services/managers/cluster-manager.spec.ts
index aac2d61b8..b954e2f8d 100644
--- a/packages/js-marker-clusterer/services/managers/cluster-manager.spec.ts
+++ b/packages/js-marker-clusterer/services/managers/cluster-manager.spec.ts
@@ -3,7 +3,7 @@ import {TestBed, async, inject} from '@angular/core/testing';
 
 import {AgmMarker} from '../../../core/directives/marker';
 import {GoogleMapsAPIWrapper} from '../../../core/services/google-maps-api-wrapper';
-import {Marker} from '../../../core/services/google-maps-types';
+import {AgmMarkerCluster} from '../../directives/marker-cluster';
 import {ClusterManager} from './cluster-manager';
 
 describe('ClusterManager', () => {
@@ -207,4 +207,34 @@ describe('ClusterManager', () => {
                  () => { expect(markerInstance.setZIndex).toHaveBeenCalledWith(zIndex); });
            })));
   });
+
+  describe('set calculator', () => {
+    it('should call the setCalculator method when the calculator changes and is a function',
+      inject(
+        [ClusterManager],
+        async (markerManager: ClusterManager) => {
+
+          const mockClusterer = { setCalculator: jest.fn() };
+          const instancePromise = Promise.resolve(mockClusterer);
+
+          const spy = jest.spyOn(markerManager, 'getClustererInstance')
+                          .mockImplementation(() => instancePromise);
+
+          const markerCluster: Partial<AgmMarkerCluster> = {};
+
+          // negative case
+          markerCluster.calculator = null;
+          markerManager.setCalculator(markerCluster as AgmMarkerCluster);
+          await instancePromise;
+          expect(mockClusterer.setCalculator).not.toHaveBeenCalled();
+
+          // positive case
+          markerCluster.calculator = jest.fn();
+          markerManager.setCalculator(markerCluster as AgmMarkerCluster);
+          await instancePromise;
+          expect(mockClusterer.setCalculator).toHaveBeenCalledTimes(1);
+
+          spy.mockRestore();
+        }));
+  });
 });
diff --git a/packages/js-marker-clusterer/services/managers/cluster-manager.ts b/packages/js-marker-clusterer/services/managers/cluster-manager.ts
index 66feabf00..d063d72df 100644
--- a/packages/js-marker-clusterer/services/managers/cluster-manager.ts
+++ b/packages/js-marker-clusterer/services/managers/cluster-manager.ts
@@ -30,8 +30,12 @@ export class ClusterManager extends MarkerManager {
     });
   }
 
+  getClustererInstance(): Promise<MarkerClustererInstance> {
+    return this._clustererInstance;
+  }
+
   addMarker(marker: AgmMarker): void {
-    const clusterPromise: Promise<MarkerClustererInstance> = this._clustererInstance;
+    const clusterPromise: Promise<MarkerClustererInstance> = this.getClustererInstance();
     const markerPromise = this._mapsWrapper
       .createMarker({
         position: {
@@ -65,7 +69,7 @@ export class ClusterManager extends MarkerManager {
     return m.then((m: Marker) => {
       this._zone.run(() => {
         m.setMap(null);
-        this._clustererInstance.then(cluster => {
+        this.getClustererInstance().then(cluster => {
           cluster.removeMarker(m);
           this._markers.delete(marker);
         });
@@ -74,31 +78,31 @@ export class ClusterManager extends MarkerManager {
   }
 
   clearMarkers(): Promise<void> {
-    return this._clustererInstance.then(cluster => {
+    return this.getClustererInstance().then(cluster => {
       cluster.clearMarkers();
     });
   }
 
   setGridSize(c: AgmMarkerCluster): void {
-    this._clustererInstance.then(cluster => {
+    this.getClustererInstance().then(cluster => {
       cluster.setGridSize(c.gridSize);
     });
   }
 
   setMaxZoom(c: AgmMarkerCluster): void {
-    this._clustererInstance.then(cluster => {
+    this.getClustererInstance().then(cluster => {
       cluster.setMaxZoom(c.maxZoom);
     });
   }
 
   setStyles(c: AgmMarkerCluster): void {
-    this._clustererInstance.then(cluster => {
+    this.getClustererInstance().then(cluster => {
       cluster.setStyles(c.styles);
     });
   }
 
   setZoomOnClick(c: AgmMarkerCluster): void {
-    this._clustererInstance.then(cluster => {
+    this.getClustererInstance().then(cluster => {
       if (c.zoomOnClick !== undefined) {
         cluster.zoomOnClick_ = c.zoomOnClick;
       }
@@ -106,7 +110,7 @@ export class ClusterManager extends MarkerManager {
   }
 
   setAverageCenter(c: AgmMarkerCluster): void {
-    this._clustererInstance.then(cluster => {
+    this.getClustererInstance().then(cluster => {
       if (c.averageCenter !== undefined) {
         cluster.averageCenter_ = c.averageCenter;
       }
@@ -114,7 +118,7 @@ export class ClusterManager extends MarkerManager {
   }
 
   setImagePath(c: AgmMarkerCluster): void {
-    this._clustererInstance.then(cluster => {
+    this.getClustererInstance().then(cluster => {
       if (c.imagePath !== undefined) {
         cluster.imagePath_ = c.imagePath;
       }
@@ -122,7 +126,7 @@ export class ClusterManager extends MarkerManager {
   }
 
   setMinimumClusterSize(c: AgmMarkerCluster): void {
-    this._clustererInstance.then(cluster => {
+    this.getClustererInstance().then(cluster => {
       if (c.minimumClusterSize !== undefined) {
         cluster.minimumClusterSize_ = c.minimumClusterSize;
       }
@@ -130,10 +134,18 @@ export class ClusterManager extends MarkerManager {
   }
 
   setImageExtension(c: AgmMarkerCluster): void {
-    this._clustererInstance.then(cluster => {
+    this.getClustererInstance().then(cluster => {
       if (c.imageExtension !== undefined) {
         cluster.imageExtension_ = c.imageExtension;
       }
     });
   }
+
+  setCalculator (c: AgmMarkerCluster): void {
+    this.getClustererInstance().then(cluster => {
+      if (typeof c.calculator === 'function') {
+        cluster.setCalculator(c.calculator);
+      }
+    });
+  }
 }