diff --git a/src/widgets/styles/qcommonstyle.cpp b/src/widgets/styles/qcommonstyle.cpp
index dc812fc15c8..2ea43027fb5 100644
--- a/src/widgets/styles/qcommonstyle.cpp
+++ b/src/widgets/styles/qcommonstyle.cpp
@@ -5050,14 +5050,16 @@ QSize QCommonStyle::sizeFromContents(ContentsType contentsType, const QStyleOpti
 #if QT_CONFIG(spinbox)
     case CT_SpinBox:
         if (const auto *spinBoxOpt = qstyleoption_cast<const QStyleOptionSpinBox *>(opt)) {
-            // Add button + frame widths
-            const qreal dpi = QStyleHelper::dpi(opt);
+            const int frameWidth = spinBoxOpt->frame
+                ? proxy()->pixelMetric(PM_SpinBoxFrameWidth, spinBoxOpt, widget)
+                : 0;
+            size += QSize(2 * frameWidth, 2 * frameWidth);
             const bool hasButtons = (spinBoxOpt->buttonSymbols != QAbstractSpinBox::NoButtons);
-            const int buttonWidth = hasButtons ? qRound(QStyleHelper::dpiScaled(16, dpi)) : 0;
-            const int frameWidth = spinBoxOpt->frame ? proxy()->pixelMetric(PM_SpinBoxFrameWidth,
-                                                                         spinBoxOpt, widget) : 0;
-
-            size += QSize(buttonWidth + 2 * frameWidth, 2 * frameWidth);
+            if (hasButtons) {
+                const auto height = qMax(8, size.height() / 2 - frameWidth);
+                const auto buttonWidth = qMax(16, qMin(height * 8 / 5, size.width() / 3));
+                size.rwidth() += buttonWidth;
+            }
         }
         break;
 #endif