diff --git a/espresso/src/com.oracle.truffle.espresso/src/com/oracle/truffle/espresso/impl/ObjectKlass.java b/espresso/src/com.oracle.truffle.espresso/src/com/oracle/truffle/espresso/impl/ObjectKlass.java
index 0af0fe3678f3..dfab92ae123e 100644
--- a/espresso/src/com.oracle.truffle.espresso/src/com/oracle/truffle/espresso/impl/ObjectKlass.java
+++ b/espresso/src/com.oracle.truffle.espresso/src/com/oracle/truffle/espresso/impl/ObjectKlass.java
@@ -60,6 +60,7 @@
 import com.oracle.truffle.espresso.analysis.hierarchy.SingleImplementor;
 import com.oracle.truffle.espresso.blocking.EspressoLock;
 import com.oracle.truffle.espresso.classfile.ConstantPool;
+import com.oracle.truffle.espresso.classfile.JavaKind;
 import com.oracle.truffle.espresso.classfile.ParserField;
 import com.oracle.truffle.espresso.classfile.ParserKlass;
 import com.oracle.truffle.espresso.classfile.ParserMethod;
@@ -1710,6 +1711,22 @@ public Source getSource() {
         return getKlassVersion().getSource();
     }
 
+    public long getInstanceSize() {
+        return computeInstanceSize();
+    }
+
+    @TruffleBoundary
+    private long computeInstanceSize() {
+        if (fieldTable.length == 0) {
+            return 0L;
+        }
+        long size = 0L;
+        for (Field f : getFieldTable()) {
+            size += f.getKind() == JavaKind.Object ? JavaKind.Long.getByteCount() : f.getKind().getByteCount();
+        }
+        return size;
+    }
+
     public final class KlassVersion {
         final Assumption assumption;
         final RuntimeConstantPool pool;
diff --git a/espresso/src/com.oracle.truffle.espresso/src/com/oracle/truffle/espresso/runtime/staticobject/StaticObject.java b/espresso/src/com.oracle.truffle.espresso/src/com/oracle/truffle/espresso/runtime/staticobject/StaticObject.java
index 7b8d22b721ce..76fa839d4d7e 100644
--- a/espresso/src/com.oracle.truffle.espresso/src/com/oracle/truffle/espresso/runtime/staticobject/StaticObject.java
+++ b/espresso/src/com.oracle.truffle.espresso/src/com/oracle/truffle/espresso/runtime/staticobject/StaticObject.java
@@ -34,6 +34,7 @@
 import com.oracle.truffle.espresso.EspressoLanguage;
 import com.oracle.truffle.espresso.blocking.BlockingSupport;
 import com.oracle.truffle.espresso.blocking.EspressoLock;
+import com.oracle.truffle.espresso.classfile.JavaKind;
 import com.oracle.truffle.espresso.descriptors.EspressoSymbols.Types;
 import com.oracle.truffle.espresso.impl.ArrayKlass;
 import com.oracle.truffle.espresso.impl.EspressoType;
@@ -190,6 +191,27 @@ public final boolean isStaticStorage() {
         return this == getKlass().getStatics();
     }
 
+    public final long getObjectSize(EspressoLanguage language) {
+        if (isNull(this)) {
+            return 0L;
+        }
+        long size = 0L;
+        size += JavaKind.Long.getByteCount(); // Klass storage
+        size += JavaKind.Long.getByteCount(); // Monitor storage
+        if (isForeignObject()) {
+            size += JavaKind.Long.getByteCount(); // Foreign storage
+            size += JavaKind.Long.getByteCount(); // Type Argument storage
+        } else if (getKlass() instanceof ArrayKlass k) {
+            JavaKind componentKind = k.getComponentType().getJavaKind();
+            size += (long) (componentKind == JavaKind.Object ? JavaKind.Long.getByteCount() : componentKind.getByteCount()) * length(language);
+        } else if (getKlass() instanceof ObjectKlass k) {
+            size += k.getInstanceSize();
+        } else {
+            EspressoContext.get(null).getLogger().warning(() -> "Unknown static object with class " + getKlass());
+        }
+        return size;
+    }
+
     /**
      * Given a guest Class, get the corresponding Klass. This method has the disadvantage of not
      * being able to constant fold the {@link Meta} object that is extracted from {@code this} if
diff --git a/espresso/src/com.oracle.truffle.espresso/src/com/oracle/truffle/espresso/substitutions/Target_sun_instrument_InstrumentationImpl.java b/espresso/src/com.oracle.truffle.espresso/src/com/oracle/truffle/espresso/substitutions/Target_sun_instrument_InstrumentationImpl.java
index 3b2fc20a9758..0fdccf573456 100644
--- a/espresso/src/com.oracle.truffle.espresso/src/com/oracle/truffle/espresso/substitutions/Target_sun_instrument_InstrumentationImpl.java
+++ b/espresso/src/com.oracle.truffle.espresso/src/com/oracle/truffle/espresso/substitutions/Target_sun_instrument_InstrumentationImpl.java
@@ -26,6 +26,7 @@
 import java.util.List;
 
 import com.oracle.truffle.api.CompilerDirectives.TruffleBoundary;
+import com.oracle.truffle.espresso.EspressoLanguage;
 import com.oracle.truffle.espresso.classfile.ClasspathEntry;
 import com.oracle.truffle.espresso.descriptors.EspressoSymbols.Names;
 import com.oracle.truffle.espresso.descriptors.EspressoSymbols.Signatures;
@@ -134,10 +135,9 @@ private static StaticObject toGuestClassArray(EspressoContext context, List<Klas
     public static long getObjectSize0(
                     @SuppressWarnings("unused") StaticObject self,
                     @SuppressWarnings("unused") long agentId,
-                    @SuppressWarnings("unused") @JavaType(Object.class) StaticObject object,
-                    @Inject EspressoContext context) {
-        throw context.getMeta().throwExceptionWithMessage(context.getMeta().java_lang_UnsupportedOperationException,
-                        "Espresso VM doesn't support getting object size from java agents. This restriction will be lifted in later versions.");
+                    @JavaType(Object.class) StaticObject object,
+                    @Inject EspressoLanguage language) {
+        return object.getObjectSize(language);
     }
 
     @Substitution(hasReceiver = true)