diff --git a/src/tools/raid-calculator/raid-calculator.service.ts b/src/tools/raid-calculator/raid-calculator.service.ts
index 9739b687..0e8ce506 100644
--- a/src/tools/raid-calculator/raid-calculator.service.ts
+++ b/src/tools/raid-calculator/raid-calculator.service.ts
@@ -11,6 +11,10 @@ const raidCalculations = {
       // total disks * size
       return (num * size) * unit;
     },
+    efficiency(num) {
+      // uses 100% of space
+      return 100;
+    },
     fault(num, size, unit) {
       return 'None';
     },
@@ -25,6 +29,10 @@ const raidCalculations = {
       // total size is size of a single drive
       return size * unit;
     },
+    efficiency(num) {
+      // 1/N
+      return (1 / num) * 100;
+    },
     fault(num, size, unit) {
       // FT = total - 1
       return `${num - 1} drive failures`;
@@ -40,6 +48,10 @@ const raidCalculations = {
       // (N-1) * S (one drive for parity)
       return ((num - 1) * size) * unit;
     },
+    efficiency(num) {
+      // 1 - (1/N)
+      return (1 - (1 / num)) * 100;
+    },
     fault(num, size, unit) {
       // always 1 failure
       return '1 drive failure';
@@ -55,6 +67,10 @@ const raidCalculations = {
       // (N-2) * S (2 parity)
       return ((num - 2) * size) * unit;
     },
+    efficiency(num) {
+      // 1 - (2/N)
+      return (1 - (2 / num)) * 100;
+    },
     fault(num, size, unit) {
       // always 2 drive failures
       return '2 drive failures';
@@ -70,6 +86,10 @@ const raidCalculations = {
       // Total disks (stripe)/2 (mirror)
       return ((num * size) / 2) * unit;
     },
+    efficiency(num) {
+      // 1/2 (1/strips per stripe, 2 in this case)
+      return 50;
+    },
     fault(num, size, unit) {
       // one per mirror
       return '1 drive failure per mirrored set';
diff --git a/src/tools/raid-calculator/raid-calculator.vue b/src/tools/raid-calculator/raid-calculator.vue
index d53f6006..10b9a890 100644
--- a/src/tools/raid-calculator/raid-calculator.vue
+++ b/src/tools/raid-calculator/raid-calculator.vue
@@ -28,6 +28,10 @@ const calculatedFaultTolerance = computed(() => {
   return raidCalculations[raidType.value].fault(diskTotal.value, diskSize.value, diskUnit.value);
 });
 
+const calculatedSpaceEfficiency = computed(() => {
+  return raidCalculations[raidType.value].efficiency(diskTotal.value);
+});
+
 function validateSetup() {
   // validate the selected RAID type against parameters
   return raidCalculations[raidType.value].validate(diskTotal.value, diskSize.value);
@@ -90,10 +94,18 @@ function validateSetup() {
             <td font-bold width="30%">
               Fault Tolerance
             </td>
-            <td :value="calculatedFaultTolerance">
+            <td>
               {{ calculatedFaultTolerance }}
             </td>
           </tr>
+          <tr>
+            <td font-bold width="30%">
+              Space Efficiency
+            </td>
+            <td>
+              {{ calculatedSpaceEfficiency }}%
+            </td>
+          </tr>
         </tbody>
       </n-table>
     </c-card>