diff --git a/src/lib/domain/calculate-project-health/calculate-project-health.ts b/src/lib/domain/calculate-project-health/calculate-project-health.ts
new file mode 100644
index 0000000000..36a00defd3
--- /dev/null
+++ b/src/lib/domain/calculate-project-health/calculate-project-health.ts
@@ -0,0 +1,65 @@
+import { hoursToMilliseconds } from 'date-fns';
+import type { IProjectHealthReport } from 'lib/types';
+import type { IFeatureType } from 'lib/types/stores/feature-type-store';
+
+const getPotentiallyStaleCount = (
+    features: Array<{
+        stale?: boolean;
+        createdAt?: Date;
+        type?: string;
+    }>,
+    featureTypes: IFeatureType[],
+) => {
+    const today = new Date().valueOf();
+
+    return features.filter((feature) => {
+        const diff = today - feature.createdAt?.valueOf();
+        const featureTypeExpectedLifetime = featureTypes.find(
+            (t) => t.id === feature.type,
+        )?.lifetimeDays;
+
+        return (
+            !feature.stale &&
+            diff >= featureTypeExpectedLifetime * hoursToMilliseconds(24)
+        );
+    }).length;
+};
+
+export const calculateProjectHealth = (
+    features: Array<{
+        stale?: boolean;
+        createdAt?: Date;
+        type?: string;
+    }>,
+    featureTypes: IFeatureType[],
+): Pick<
+    IProjectHealthReport,
+    'staleCount' | 'potentiallyStaleCount' | 'activeCount'
+> => ({
+    potentiallyStaleCount: getPotentiallyStaleCount(features, featureTypes),
+    activeCount: features.filter((f) => !f.stale).length,
+    staleCount: features.filter((f) => f.stale).length,
+});
+
+export const getHealthRating = (
+    features: Array<{
+        stale?: boolean;
+        createdAt?: Date;
+        type?: string;
+    }>,
+    featureTypes: IFeatureType[],
+): number => {
+    const { potentiallyStaleCount, activeCount, staleCount } =
+        calculateProjectHealth(features, featureTypes);
+    const toggleCount = activeCount + staleCount;
+
+    const startPercentage = 100;
+    const stalePercentage = (staleCount / toggleCount) * 100 || 0;
+    const potentiallyStalePercentage =
+        (potentiallyStaleCount / toggleCount) * 100 || 0;
+    const rating = Math.round(
+        startPercentage - stalePercentage - potentiallyStalePercentage,
+    );
+
+    return rating;
+};
diff --git a/src/lib/services/project-health-service.ts b/src/lib/services/project-health-service.ts
index 86ede7b754..1d0de140d2 100644
--- a/src/lib/services/project-health-service.ts
+++ b/src/lib/services/project-health-service.ts
@@ -1,18 +1,20 @@
 import { IUnleashStores } from '../types/stores';
 import { IUnleashConfig } from '../types/option';
 import { Logger } from '../logger';
-import {
-    FeatureToggle,
-    IFeatureOverview,
-    IProject,
-    IProjectHealthReport,
-} from '../types/model';
-import { IFeatureToggleStore } from '../types/stores/feature-toggle-store';
-import { IFeatureTypeStore } from '../types/stores/feature-type-store';
-import { IProjectStore } from '../types/stores/project-store';
+import type { IProject, IProjectHealthReport } from '../types/model';
+import type { IFeatureToggleStore } from '../types/stores/feature-toggle-store';
+import type {
+    IFeatureType,
+    IFeatureTypeStore,
+} from '../types/stores/feature-type-store';
+import type { IProjectStore } from '../types/stores/project-store';
 import { hoursToMilliseconds } from 'date-fns';
 import Timer = NodeJS.Timer;
 import ProjectService from './project-service';
+import {
+    calculateProjectHealth,
+    getHealthRating,
+} from '../domain/calculate-project-health/calculate-project-health';
 
 export default class ProjectHealthService {
     private logger: Logger;
@@ -23,7 +25,7 @@ export default class ProjectHealthService {
 
     private featureToggleStore: IFeatureToggleStore;
 
-    private featureTypes: Map<string, number>;
+    private featureTypes: IFeatureType[];
 
     private healthRatingTimer: Timer;
 
@@ -45,7 +47,7 @@ export default class ProjectHealthService {
         this.projectStore = projectStore;
         this.featureTypeStore = featureTypeStore;
         this.featureToggleStore = featureToggleStore;
-        this.featureTypes = new Map();
+        this.featureTypes = [];
         this.healthRatingTimer = setInterval(
             () => this.setHealthRating(),
             hoursToMilliseconds(1),
@@ -57,85 +59,38 @@ export default class ProjectHealthService {
     async getProjectHealthReport(
         projectId: string,
     ): Promise<IProjectHealthReport> {
+        if (this.featureTypes.length === 0) {
+            this.featureTypes = await this.featureTypeStore.getAll();
+        }
+
         const overview = await this.projectService.getProjectOverview(
             projectId,
             false,
             undefined,
         );
+
+        const healthRating = calculateProjectHealth(
+            overview.features,
+            this.featureTypes,
+        );
+
         return {
             ...overview,
-            potentiallyStaleCount: await this.potentiallyStaleCount(
-                overview.features,
-            ),
-            activeCount: this.activeCount(overview.features),
-            staleCount: this.staleCount(overview.features),
+            ...healthRating,
         };
     }
 
-    private async potentiallyStaleCount(
-        features: Pick<FeatureToggle, 'createdAt' | 'stale' | 'type'>[],
-    ): Promise<number> {
-        const today = new Date().valueOf();
-        if (this.featureTypes.size === 0) {
-            const types = await this.featureTypeStore.getAll();
-            types.forEach((type) => {
-                this.featureTypes.set(
-                    type.name.toLowerCase(),
-                    type.lifetimeDays,
-                );
-            });
-        }
-        return features.filter((feature) => {
-            const diff = today - feature.createdAt.valueOf();
-            const featureTypeExpectedLifetime = this.featureTypes.get(
-                feature.type,
-            );
-            return (
-                !feature.stale &&
-                diff >= featureTypeExpectedLifetime * hoursToMilliseconds(24)
-            );
-        }).length;
-    }
-
-    private activeCount(features: IFeatureOverview[]): number {
-        return features.filter((f) => !f.stale).length;
-    }
-
-    private staleCount(features: IFeatureOverview[]): number {
-        return features.filter((f) => f.stale).length;
-    }
-
     async calculateHealthRating(project: IProject): Promise<number> {
+        if (this.featureTypes.length === 0) {
+            this.featureTypes = await this.featureTypeStore.getAll();
+        }
+
         const toggles = await this.featureToggleStore.getAll({
             project: project.id,
             archived: false,
         });
 
-        const activeToggles = toggles.filter((feature) => !feature.stale);
-        const staleToggles = toggles.length - activeToggles.length;
-        const potentiallyStaleToggles = await this.potentiallyStaleCount(
-            activeToggles,
-        );
-        return this.getHealthRating(
-            toggles.length,
-            staleToggles,
-            potentiallyStaleToggles,
-        );
-    }
-
-    private getHealthRating(
-        toggleCount: number,
-        staleToggleCount: number,
-        potentiallyStaleCount: number,
-    ): number {
-        const startPercentage = 100;
-        const stalePercentage = (staleToggleCount / toggleCount) * 100 || 0;
-        const potentiallyStalePercentage =
-            (potentiallyStaleCount / toggleCount) * 100 || 0;
-        const rating = Math.round(
-            startPercentage - stalePercentage - potentiallyStalePercentage,
-        );
-        return rating;
+        return getHealthRating(toggles, this.featureTypes);
     }
 
     async setHealthRating(): Promise<void> {