diff --git a/apps/studio/components/interfaces/SQLEditor/UtilityPanel/ChartConfig.tsx b/apps/studio/components/interfaces/SQLEditor/UtilityPanel/ChartConfig.tsx
index a54a698c6e2..870d33a0c18 100644
--- a/apps/studio/components/interfaces/SQLEditor/UtilityPanel/ChartConfig.tsx
+++ b/apps/studio/components/interfaces/SQLEditor/UtilityPanel/ChartConfig.tsx
@@ -25,6 +25,7 @@ import { Admonition } from 'ui-patterns'
 import { ButtonTooltip } from '@/components/ui/ButtonTooltip'
 import BarChart from '@/components/ui/Charts/BarChart'
 import NoDataPlaceholder from '@/components/ui/Charts/NoDataPlaceholder'
+import { getCumulativeResults } from '@/components/ui/QueryBlock/QueryBlock.utils'
 import { useLocalStorageQuery } from '@/hooks/misc/useLocalStorage'
 
 type Results = { rows: readonly any[] }
@@ -40,21 +41,6 @@ export type ChartConfig = {
   logScale?: boolean
 }
 
-const getCumulativeResults = (results: Results, config: ChartConfig) => {
-  if (!results?.rows?.length) {
-    return []
-  }
-
-  const cumulativeResults = results.rows.reduce((acc, row) => {
-    const prev = acc[acc.length - 1] || {}
-    const next = {
-      ...row,
-      [config.yKey]: (prev[config.yKey] || 0) + row[config.yKey],
-    }
-    return [...acc, next]
-  }, [])
-  return cumulativeResults
-}
 const VALID_RESULT_KEY_TYPES = ['number', 'string', 'date']
 
 type ChartConfigProps = {
diff --git a/apps/studio/components/ui/QueryBlock/QueryBlock.utils.ts b/apps/studio/components/ui/QueryBlock/QueryBlock.utils.ts
index 7a7ffbb9708..342f5b17a60 100644
--- a/apps/studio/components/ui/QueryBlock/QueryBlock.utils.ts
+++ b/apps/studio/components/ui/QueryBlock/QueryBlock.utils.ts
@@ -1,4 +1,4 @@
-import { ChartConfig } from '@/components/interfaces/SQLEditor/UtilityPanel/ChartConfig'
+import type { ChartConfig } from '@/components/interfaces/SQLEditor/UtilityPanel/ChartConfig'
 
 export const checkHasNonPositiveValues = (data: Record<string, unknown>[], key: string): boolean =>
   data.some((row) => (row[key] as number) <= 0)
@@ -47,16 +47,19 @@ export const formatLogTick = (value: number): string => {
   return value.toLocaleString()
 }
 
-export const getCumulativeResults = (results: { rows: any[] }, config: ChartConfig) => {
+export const getCumulativeResults = (results: { rows: readonly any[] }, config: ChartConfig) => {
   if (!results?.rows?.length) {
     return []
   }
 
   const cumulativeResults = results.rows.reduce((acc, row) => {
     const prev = acc[acc.length - 1] || {}
+    // Coerce to Number before adding: Postgres returns `bigint`, `numeric`,
+    // `money` and `count(*)` columns as strings, so a bare `+` would
+    // concatenate (e.g. "10" + "20" -> "1020") instead of summing.
     const next = {
       ...row,
-      [config.yKey]: (prev[config.yKey] || 0) + row[config.yKey],
+      [config.yKey]: (Number(prev[config.yKey]) || 0) + (Number(row[config.yKey]) || 0),
     }
     return [...acc, next]
   }, [])
diff --git a/apps/studio/tests/components/ui/QueryBlock/QueryBlock.utils.test.ts b/apps/studio/tests/components/ui/QueryBlock/QueryBlock.utils.test.ts
index 99c99109098..b48ad9aafaf 100644
--- a/apps/studio/tests/components/ui/QueryBlock/QueryBlock.utils.test.ts
+++ b/apps/studio/tests/components/ui/QueryBlock/QueryBlock.utils.test.ts
@@ -156,4 +156,52 @@ describe('getCumulativeResults', () => {
     const output = getCumulativeResults(results, config)
     expect(output).toEqual([{ x: 'a', y: 42 }])
   })
+
+  // Postgres returns `bigint`, `numeric`, `money` and `count(*)` columns as
+  // strings, so the running total must sum numerically rather than concatenate.
+  it('sums numeric string yKey values instead of concatenating them', () => {
+    const results = {
+      rows: [
+        { x: 'a', y: '10' },
+        { x: 'b', y: '20' },
+        { x: 'c', y: '30' },
+      ],
+    }
+    const config = {
+      type: 'bar' as const,
+      xKey: 'x',
+      yKey: 'y',
+      cumulative: true,
+      showLabels: false,
+      showGrid: false,
+    }
+    const output = getCumulativeResults(results, config)
+    expect(output).toEqual([
+      { x: 'a', y: 10 },
+      { x: 'b', y: 30 },
+      { x: 'c', y: 60 },
+    ])
+  })
+
+  it('treats null/undefined and non-numeric yKey values as 0', () => {
+    const results = {
+      rows: [
+        { x: 'a', y: null },
+        { x: 'b', y: '5' },
+        { x: 'c', y: undefined },
+        { x: 'd', y: 'not-a-number' },
+        { x: 'e', y: 4 },
+      ],
+    }
+    const config = {
+      type: 'bar' as const,
+      xKey: 'x',
+      yKey: 'y',
+      cumulative: true,
+      showLabels: false,
+      showGrid: false,
+    }
+    const output = getCumulativeResults(results, config)
+    expect(output.map((row: { y: number }) => row.y)).toEqual([0, 5, 5, 5, 9])
+  })
 })