diff --git a/src/components/ModifierRow.tsx b/src/components/ModifierRow.tsx
index 95afbc3..ba1ce79 100644
--- a/src/components/ModifierRow.tsx
+++ b/src/components/ModifierRow.tsx
@@ -65,10 +65,12 @@ const ModifierRow: Component<ModifierRowProps> = (props) => {
                         value={props.modifier.value}
                         onUpdate={(val) => props.onUpdate(props.modifier.id, { value: val })}
                         class="w-20 text-right text-sm border-b border-dashed border-border focus:border-primary outline-none bg-transparent text-primary font-medium"
-                        placeholder="0.00"
+                        placeholder={props.modifier.moduleId === 'man-hours' ? "Factor" : "0.00"}
                     />
-                    <Show when={props.modifier.valueType === 'unit' && props.modifier.unitLabel}>
-                        <span class="text-[10px] font-bold text-primary/60">{props.modifier.unitLabel}</span>
+                    <Show when={(props.modifier.valueType === 'unit' && props.modifier.unitLabel) || props.modifier.moduleId === 'man-hours'}>
+                        <span class="text-[10px] font-bold text-primary/60">
+                            {props.modifier.moduleId === 'man-hours' ? 'factor' : props.modifier.unitLabel}
+                        </span>
                     </Show>
                 </div>
 
diff --git a/src/utils/modifier-registry.ts b/src/utils/modifier-registry.ts
index 4609b82..479ba97 100644
--- a/src/utils/modifier-registry.ts
+++ b/src/utils/modifier-registry.ts
@@ -28,15 +28,15 @@ const TaxModule: ModifierModule = {
 const ManHoursModule: ModifierModule = {
     id: 'man-hours',
     name: 'Man-Hours',
-    description: 'Calculates estimated labor hours. Does not affect monetary total.',
+    description: 'Calculates labor hours by dividing the sub-scope subtotal by a production factor.',
     defaultLabel: 'Estimated Hours',
-    defaultValue: 0,
+    defaultValue: 30,
     defaultValueType: 'unit',
-    defaultUnitLabel: 'hrs',
+    defaultUnitLabel: 'factor',
     calculate: () => 0,
     calculateDisplay: (m, base) => {
-        if (m.valueType === 'percent') return base * (m.value / 100);
-        return m.value;
+        const factor = m.value || 1;
+        return base / factor;
     }
 };