diff --git a/app/presenters/response_rate_presenter.rb b/app/presenters/response_rate_presenter.rb
index 7e2b39d6..80193519 100644
--- a/app/presenters/response_rate_presenter.rb
+++ b/app/presenters/response_rate_presenter.rb
@@ -27,6 +27,10 @@ class ResponseRatePresenter
     percentage > 75 ? '#49416D' : '#FFC857'
   end
 
+  def hover_message
+    "Percentages based on #{ actual_count } out of #{ respondents_count.round } #{ focus }s completing at least 25% of the survey."
+  end
+
   private
 
   def cap_at_100(value)
diff --git a/app/views/overview/_response_rate.html.erb b/app/views/overview/_response_rate.html.erb
index 5ec1c145..46dd71ca 100644
--- a/app/views/overview/_response_rate.html.erb
+++ b/app/views/overview/_response_rate.html.erb
@@ -1,8 +1,14 @@
-<div class="overall-response-rate-container">
+<div 
+  class="overall-response-rate-container"
+  data-bs-toggle="popover" 
+  data-bs-trigger="hover focus" 
+  data-bs-content="<%= response_rate_presenter.hover_message %>"
+  data-bs-placement="top"
+>
   <div>Response Rates as of <%= response_rate_presenter.date.to_date.strftime("%m/%d/%y") %> </div>
   <div style="display: flex; justify-content:space-between; width: 100px;">
   <div><%= response_rate_presenter.focus.capitalize %> </div>
   <%= render partial: "response_rate_graphic", locals: {response_rate_presenter: response_rate_presenter}, cached: true %>
   <div><%= response_rate_presenter.percentage %>% </div>
   </div>
-</div>
+</div>
\ No newline at end of file