diff --git a/templates/dashboard/_chart_migrations.html b/templates/dashboard/_chart_migrations.html
index 0e48e37..dc8a47d 100644
--- a/templates/dashboard/_chart_migrations.html
+++ b/templates/dashboard/_chart_migrations.html
@@ -13,7 +13,9 @@
                 </div>
                 <div id="currentCpuStdBlock" class="flex items-center gap-1 text-xs">
                     <div class="w-3 h-0.5 bg-error/60"></div>
-                    <span class="text-error/60">±0.5σ: <span id="currentCpuStd">0</span>%</span>
+                    <span class="tooltip tooltip-top text-error/60 cursor-help" data-tip="σ = √(Σ(xᵢ−μ)²/n)" aria-label="Формула расчёта ±0.5σ">
+                        <span class="text-error/60">±0.5σ: <span id="currentCpuStd">0</span>%</span>
+                    </span>
                 </div>
             </div>
         </div>