diff --git a/src/calculate-pr-avg-tat.ts b/src/calculate-pr-avg-tat.ts
new file mode 100644
index 0000000..67fe135
--- /dev/null
+++ b/src/calculate-pr-avg-tat.ts
@@ -0,0 +1,58 @@
+import {
+  contributorAggregateQueries,
+  activityQueries,
+  Database,
+  Logger,
+} from "@ohcnetwork/leaderboard-api";
+import { ActivityDefinition } from "./activity";
+import { formatDuration, intervalToDuration } from "date-fns";
+
+export async function calculatePrAvgTat(db: Database, logger: Logger) {
+  const allActivities = await activityQueries.getAll(db);
+  const activities = allActivities.filter(activity => activity.activity_definition === ActivityDefinition.PR_MERGED);
+
+  const contributorPRs = new Map<string, typeof activities>();
+  for (const activity of activities) {
+    if (!activity.contributor) continue;
+
+    const prs = contributorPRs.get(activity.contributor) || [];
+    prs.push(activity);
+    contributorPRs.set(activity.contributor, prs);
+  }
+
+  for (const [username, prs] of contributorPRs) {
+    let totalTat = 0;
+    let prCount = 0;
+
+    for (const pr of prs) {
+      const meta = pr.meta as any;
+      if (meta?.created_at && meta?.merged_at) {
+        totalTat += new Date(meta.merged_at).getTime() - new Date(meta.created_at).getTime();
+        prCount++;
+      }
+    }
+
+    if (prCount === 0) continue;
+
+    const avgTat = totalTat / prCount;
+    const avgTatHours = avgTat / (1000 * 60 * 60);
+
+    const duration = intervalToDuration({ start: 0, end: avgTat });
+    const formattedDuration = formatDuration(duration, { format: ['months', 'weeks', 'days', 'hours'] });
+
+    await contributorAggregateQueries.upsert(db, {
+      aggregate: "avg_tat",
+      contributor: username,
+      value: {
+        type: "string",
+        value: formattedDuration,
+      },
+      meta: {
+        calculated_at: new Date().toISOString(),
+        pr_count: prCount,
+      },
+    });
+  }
+
+  logger.info(`Calculated PR avg TAT for ${contributorPRs.size} contributors`);
+}
\ No newline at end of file
diff --git a/src/get-activities.ts b/src/get-activities.ts
index e66426f..9a20052 100644
--- a/src/get-activities.ts
+++ b/src/get-activities.ts
@@ -701,9 +701,10 @@ function activitiesFromPullRequests(
         link: pullRequest.url,
         points: null,
         meta: {
-          pr_avg_tat:
-            new Date(pullRequest.merged_at).getTime() -
-            new Date(pullRequest.created_at).getTime(),
+          created_at: pullRequest.created_at,
+          merged_at: pullRequest.merged_at,
+          pr_number: pullRequest.number,
+          repo: repo,
         },
       });
     }
diff --git a/src/index.ts b/src/index.ts
index 7cc04d2..d22c1f7 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -1,10 +1,12 @@
-/**
+/**  
  * Leaderboard github plugin
  */
 
 import { getActivities } from "@/src/get-activities";
 import type { Plugin, PluginContext } from "@ohcnetwork/leaderboard-api";
 import { ActivityDefinition } from "./activity";
+import { calculatePrAvgTat } from "./calculate-pr-avg-tat";
+import { contributorAggregateDefinitionQueries } from "@ohcnetwork/leaderboard-api";
 
 const plugin: Plugin = {
   name: "@leaderboard/plugin-leaderboard-github-plugin",
@@ -96,6 +98,13 @@ const plugin: Plugin = {
       );
     }
 
+    await contributorAggregateDefinitionQueries.upsert(ctx.db, {
+      slug: "avg_tat",
+      name: "PR Merge Turn Around Time",
+      description: "Average time taken from opening to merging a PR",
+      hidden: false,
+    });
+
     ctx.logger.info("Setup complete");
   },
 
@@ -103,8 +112,11 @@ const plugin: Plugin = {
     ctx.logger.info("Starting leaderboard-github-plugin data scraping...");
 
     await getActivities(ctx);
+
+    await calculatePrAvgTat(ctx.db, ctx.logger);
+
     ctx.logger.info("Scraping complete");
   },
 };
 
-export default plugin;
+export default plugin;
\ No newline at end of file