diff --git a/src/lib/server/hosts/capacity-history.ts b/src/lib/server/hosts/capacity-history.ts
index 9e78514..0fe3c40 100644
--- a/src/lib/server/hosts/capacity-history.ts
+++ b/src/lib/server/hosts/capacity-history.ts
@@ -1,5 +1,6 @@
 import { db } from '../db/index.js';
 import type { CapacityHistory, CapacityQuery, CapacityRange } from '../../capacity.js';
+import type { HostMode } from '../../hosts.js';
 import { readTemperatureHistory } from './temperatures.js';
 
 const windows: Record<CapacityRange, { duration: number; bucketMs: number }> = {
@@ -16,13 +17,14 @@ export function readCapacityHistory(query: CapacityQuery, now = Date.now()): Cap
     const count = duration / bucketMs;
     const hosts = handle
         .prepare(
-            `SELECT id,name,created_at FROM ec_hosts
+            `SELECT id,name,created_at,mode FROM ec_hosts
         WHERE deleted_at IS NULL ${query.hostId ? 'AND id=?' : ''} ORDER BY id`
         )
         .all(...(query.hostId ? [query.hostId] : [])) as {
         id: string;
         name: string;
         created_at: string;
+        mode: HostMode;
     }[];
     // The primary key bounds each host scan to the selected interval. Aggregate
     // before crossing the worker boundary; do not return raw heartbeat rows.
@@ -44,6 +46,9 @@ export function readCapacityHistory(query: CapacityQuery, now = Date.now()): Cap
         expectedHosts: 0
     }));
     for (const host of hosts) {
+        // Current mode determines available capacity; keep inactive hosts in
+        // the separate temperature history for diagnostics.
+        if (host.mode !== 'active') continue;
         const createdAt = Date.parse(host.created_at);
         for (const point of points) {
             if (createdAt <= Math.min(now, point.at + bucketMs)) point.expectedHosts++;
diff --git a/src/lib/ui/components/capacity/CapacityChart.svelte b/src/lib/ui/components/capacity/CapacityChart.svelte
index b93a0ee..f8e50bc 100644
--- a/src/lib/ui/components/capacity/CapacityChart.svelte
+++ b/src/lib/ui/components/capacity/CapacityChart.svelte
@@ -234,10 +234,11 @@
     <details class="about">
         <summary>About this chart</summary>
         <p class="note">
-            Available host resources after the operating-system reserve, averaged per period. Gaps
-            mean reporting is incomplete. Reporting-host coverage is shown for each selected period.
-            This history includes all workloads on the selected hosts; it does not reconstruct
-            historical launch eligibility, queued jobs, or port availability.
+            Available resources from currently active hosts after the operating-system reserve,
+            averaged per period. Disabled and draining hosts are excluded. Gaps mean reporting is
+            incomplete. Reporting-host coverage is shown for each selected period. This history
+            includes all workloads on the selected hosts; it does not reconstruct historical launch
+            eligibility, queued jobs, or port availability.
         </p>
         <details bind:open={tableOpen}>
             <summary>View history data · {$timeZone.replaceAll('_', ' ')}</summary>
diff --git a/tests/unit/capacity-history.test.ts b/tests/unit/capacity-history.test.ts
index 9f0c699..e79e767 100644
--- a/tests/unit/capacity-history.test.ts
+++ b/tests/unit/capacity-history.test.ts
@@ -161,6 +161,82 @@ describe('capacity history', () => {
         });
     });
 
+    it('excludes inactive hosts from resource totals and coverage while retaining their temperatures', async () => {
+        await host('active');
+        await host('disabled');
+        await host('draining');
+        await host('disabled-without-samples');
+        await sample('active', epoch - 45_000);
+        await sample('disabled', epoch - 45_000);
+        await sample('disabled', epoch - 90_000);
+        await sample('draining', epoch - 45_000);
+        const { db } = await import('../../src/lib/server/db/index.js');
+        db().prepare("UPDATE ec_hosts SET mode='disabled' WHERE id LIKE 'disabled%'").run();
+        db().prepare("UPDATE ec_hosts SET mode='draining' WHERE id='draining'").run();
+        const { recordTemperatures } = await import('../../src/lib/server/hosts/temperatures.js');
+        recordTemperatures(
+            'disabled',
+            {
+                temperatures: [
+                    {
+                        id: 'pkg',
+                        device: 'coretemp',
+                        kind: 'cpu-package',
+                        label: 'Package id 0',
+                        celsius: 65
+                    }
+                ]
+            },
+            new Date(epoch - 45_000).toISOString()
+        );
+        const { readCapacityHistory } =
+            await import('../../src/lib/server/hosts/capacity-history.js');
+        const history = readCapacityHistory(query, epoch);
+        expect(history.points.at(-1)).toMatchObject({
+            memoryBytesAvailable: 4 * GiB - 500_000_000,
+            reportingHosts: 1,
+            expectedHosts: 1
+        });
+        expect(history.points.at(-1)?.cpuCoresAvailable).toBeCloseTo(5.6);
+        expect(history.points.at(-2)).toMatchObject({
+            cpuCoresAvailable: null,
+            memoryBytesAvailable: null,
+            reportingHosts: 0,
+            expectedHosts: 1
+        });
+        expect(
+            history.temperatures.find((series) => series.hostId === 'disabled')?.points.at(-1)
+        ).toMatchObject({ celsius: 65 });
+    });
+
+    it.each(['disabled', 'draining'])(
+        'omits a selected %s host until it is active again',
+        async (mode) => {
+            await host('one');
+            await sample('one', epoch - 45_000);
+            const { db } = await import('../../src/lib/server/db/index.js');
+            db().prepare('UPDATE ec_hosts SET mode=? WHERE id=?').run(mode, 'one');
+            const { readCapacityHistory } =
+                await import('../../src/lib/server/hosts/capacity-history.js');
+            for (const hostId of [null, 'one']) {
+                const history = readCapacityHistory({ ...query, hostId }, epoch);
+                expect(
+                    history.points.every(
+                        (point) =>
+                            point.cpuCoresAvailable === null &&
+                            point.memoryBytesAvailable === null &&
+                            point.reportingHosts === 0 &&
+                            point.expectedHosts === 0
+                    )
+                ).toBe(true);
+            }
+            db().prepare("UPDATE ec_hosts SET mode='active' WHERE id='one'").run();
+            const history = readCapacityHistory({ ...query, hostId: 'one' }, epoch);
+            expect(history.points.at(-1)?.cpuCoresAvailable).toBeCloseTo(5.6);
+            expect(history.points.at(-1)).toMatchObject({ reportingHosts: 1, expectedHosts: 1 });
+        }
+    );
+
     it('scopes history to the selected registered host and does not add hosts before they existed', async () => {
         await host('one');
         await host('two', epoch - 30_000);