diff --git a/apps/start/src/components/profiles/profile-activity.tsx b/apps/start/src/components/profiles/profile-activity.tsx
index a4e4a21a..f8509e1f 100644
--- a/apps/start/src/components/profiles/profile-activity.tsx
+++ b/apps/start/src/components/profiles/profile-activity.tsx
@@ -7,6 +7,7 @@ import {
   format,
   formatISO,
   isSameMonth,
+  isToday,
   startOfMonth,
   subMonths,
 } from 'date-fns';
@@ -18,15 +19,26 @@ import {
   WidgetTitle,
 } from '../overview/overview-widget';
 import { Button } from '../ui/button';
+import { Tooltiper } from '../ui/tooltip';
 
 type Props = {
   data: { count: number; date: string }[];
 };
 
+function getOpacityLevel(count: number, maxCount: number): number {
+  if (count === 0 || maxCount === 0) return 0;
+  const ratio = count / maxCount;
+  if (ratio <= 0.25) return 0.25;
+  if (ratio <= 0.5) return 0.5;
+  if (ratio <= 0.75) return 0.75;
+  return 1;
+}
+
 const MonthCalendar = ({
   month,
   data,
-}: { month: Date; data: Props['data'] }) => (
+  maxCount,
+}: { month: Date; data: Props['data']; maxCount: number }) => (
   <div>
     <div className="mb-2 text-sm">{format(month, 'MMMM yyyy')}</div>
     <div className="-m-1 grid grid-cols-7 gap-1 p-1">
@@ -37,14 +49,42 @@ const MonthCalendar = ({
         const hit = data.find((item) =>
           item.date.includes(formatISO(date, { representation: 'date' })),
         );
+        const opacity = hit ? getOpacityLevel(hit.count, maxCount) : 0;
         return (
-          <div
+          <Tooltiper
             key={date.toISOString()}
-            className={cn(
-              'aspect-square w-full rounded',
-              hit ? 'bg-highlight' : 'bg-def-200',
-            )}
-          />
+            asChild
+            content={
+              <div className="text-sm col gap-1">
+                <div className="font-medium">{format(date, 'EEEE, MMM d')}</div>
+                {hit ? (
+                  <div className="text-muted-foreground">
+                    {hit.count} {hit.count === 1 ? 'event' : 'events'}
+                  </div>
+                ) : (
+                  <div className="text-muted-foreground">No activity</div>
+                )}
+              </div>
+            }
+          >
+            <div
+              className={cn(
+                'aspect-square w-full rounded cursor-default group hover:ring-1 hover:ring-foreground overflow-hidden',
+              )}
+            >
+              <div
+                className={cn(
+                  'size-full group-hover:shadow-[inset_0_0_0_2px_var(--background)] rounded',
+                  isToday(date)
+                    ? 'bg-highlight'
+                    : hit
+                      ? 'bg-foreground'
+                      : 'bg-def-200',
+                )}
+                style={hit && !isToday(date) ? { opacity } : undefined}
+              />
+            </div>
+          </Tooltiper>
         );
       })}
     </div>
@@ -53,6 +93,7 @@ const MonthCalendar = ({
 
 export const ProfileActivity = ({ data }: Props) => {
   const [startDate, setStartDate] = useState(startOfMonth(new Date()));
+  const maxCount = Math.max(...data.map((item) => item.count), 0);
 
   return (
     <Widget className="w-full">
@@ -83,6 +124,7 @@ export const ProfileActivity = ({ data }: Props) => {
               key={offset}
               month={subMonths(startDate, offset)}
               data={data}
+              maxCount={maxCount}
             />
           ))}
         </div>