diff --git a/src/main/java/io/github/avegera/predicate4j/api/WhereList.java b/src/main/java/io/github/avegera/predicate4j/api/WhereList.java
index 6efeac1..9690717 100644
--- a/src/main/java/io/github/avegera/predicate4j/api/WhereList.java
+++ b/src/main/java/io/github/avegera/predicate4j/api/WhereList.java
@@ -8,11 +8,9 @@ public interface WhereList<T, R> extends WhereObject<T, List<R>> {
 
     RichPredicate<T> notEmpty();
 
-    RichPredicate<T> hasSize(int size);
-
-    RichPredicate<T> notHaveSize(int size);
-
     RichPredicate<T> contains(R element);
 
     RichPredicate<T> notContains(R element);
+
+    WhereNumber<T, Integer> size();
 }
\ No newline at end of file
diff --git a/src/main/java/io/github/avegera/predicate4j/impl/WhereListImpl.java b/src/main/java/io/github/avegera/predicate4j/impl/WhereListImpl.java
index 78b73fd..cfd2597 100644
--- a/src/main/java/io/github/avegera/predicate4j/impl/WhereListImpl.java
+++ b/src/main/java/io/github/avegera/predicate4j/impl/WhereListImpl.java
@@ -3,6 +3,7 @@
 import io.github.avegera.predicate4j.Predicates;
 import io.github.avegera.predicate4j.api.RichPredicate;
 import io.github.avegera.predicate4j.api.WhereList;
+import io.github.avegera.predicate4j.api.WhereNumber;
 
 import java.util.List;
 import java.util.function.Function;
@@ -28,22 +29,21 @@ public RichPredicate<T> notEmpty() {
     }
 
     @Override
-    public RichPredicate<T> hasSize(int size) {
-        return getPredicate(Predicates.hasSize(size));
+    public RichPredicate<T> contains(R element) {
+        return getPredicate(Predicates.containsElement(element));
     }
 
     @Override
-    public RichPredicate<T> notHaveSize(int size) {
-        return getPredicate(Predicates.notHaveSize(size));
+    public RichPredicate<T> notContains(R element) {
+        return getPredicate(Predicates.notContainsElement(element));
     }
 
     @Override
-    public RichPredicate<T> contains(R element) {
-        return getPredicate(Predicates.containsElement(element));
+    public WhereNumber<T, Integer> size() {
+        return new WhereNumberImpl<>(this::getSize, previousPredicate);
     }
 
-    @Override
-    public RichPredicate<T> notContains(R element) {
-        return getPredicate(Predicates.notContainsElement(element));
+    private Integer getSize(T object) {
+        return getInt(object, List::size);
     }
 }
\ No newline at end of file
diff --git a/src/main/java/io/github/avegera/predicate4j/impl/WhereObjectImpl.java b/src/main/java/io/github/avegera/predicate4j/impl/WhereObjectImpl.java
index 611312e..5a8c5d6 100644
--- a/src/main/java/io/github/avegera/predicate4j/impl/WhereObjectImpl.java
+++ b/src/main/java/io/github/avegera/predicate4j/impl/WhereObjectImpl.java
@@ -73,6 +73,14 @@ protected RichPredicate<T> getPredicate(Predicate<R> predicate) {
         return new RichPredicateImpl<>(previousPredicate.and(currentPredicate));
     }
 
+    protected Integer getInt(T object, Function<R, Integer> intFunction) {
+        if (mapper == null) {
+            return null;
+        }
+        R result = mapper.apply(object);
+        return result != null ? intFunction.apply(result) : 0;
+    }
+
     private Predicate<T> getPredicateWithMapper(Function<T, R> mapper, Predicate<R> predicate) {
         return object -> object != null && predicate != null && predicate.test(mapper.apply(object));
     }
diff --git a/src/main/java/io/github/avegera/predicate4j/impl/WhereStringImpl.java b/src/main/java/io/github/avegera/predicate4j/impl/WhereStringImpl.java
index 7a8f3e6..2fbcf07 100644
--- a/src/main/java/io/github/avegera/predicate4j/impl/WhereStringImpl.java
+++ b/src/main/java/io/github/avegera/predicate4j/impl/WhereStringImpl.java
@@ -73,10 +73,6 @@ public WhereNumber<T, Integer> length() {
     }
 
     private Integer getLength(T object) {
-        if (mapper == null) {
-            return null;
-        }
-        String string = mapper.apply(object);
-        return string != null ? string.length() : 0;
+        return getInt(object, String::length);
     }
 }
\ No newline at end of file
diff --git a/src/test/java/io/github/avegera/predicate4j/WhereTest.java b/src/test/java/io/github/avegera/predicate4j/WhereTest.java
index 0cc1f26..38208a9 100644
--- a/src/test/java/io/github/avegera/predicate4j/WhereTest.java
+++ b/src/test/java/io/github/avegera/predicate4j/WhereTest.java
@@ -1218,8 +1218,8 @@ void mappedListIsEmpty() {
         }
 
         @Nested
-        @DisplayName(".hasSize(size)")
-        class HasSize {
+        @DisplayName(".size().isEqualTo(size)")
+        class SizeIsEqualTo {
 
             @Nested
             @DisplayName("returns true when")
@@ -1228,21 +1228,21 @@ class ReturnsTrueWhen {
                 @Test
                 @DisplayName("mapped list has the specified size")
                 void mappedListHasSpecifiedSize() {
-                    Predicate<Customer> predicate = where().list(Customer::roles).hasSize(2);
+                    Predicate<Customer> predicate = where().list(Customer::roles).size().isEqualTo(2);
                     assertThat(predicate).accepts(new Customer(asList("Admin", "User"), null));
                 }
 
                 @Test
                 @DisplayName("mapped list is empty and specified size is zero")
                 void mappedListIsEmptyAndSpecifiedSizeIsZero() {
-                    Predicate<Customer> predicate = where().list(Customer::roles).hasSize(0);
+                    Predicate<Customer> predicate = where().list(Customer::roles).size().isEqualTo(0);
                     assertThat(predicate).accepts(new Customer(new ArrayList<>(), null));
                 }
 
                 @Test
                 @DisplayName("mapped list is null and specified size is zero")
                 void mappedListIsNullAndSpecifiedSizeIsZero() {
-                    Predicate<Customer> predicate = where().list(Customer::roles).hasSize(0);
+                    Predicate<Customer> predicate = where().list(Customer::roles).size().isEqualTo(0);
                     assertThat(predicate).accepts(new Customer(new ArrayList<>(), null));
                 }
             }
@@ -1254,29 +1254,29 @@ class ReturnsFalseWhen {
                 @Test
                 @DisplayName("mapped list has a different size than specified")
                 void mappedListHasDifferentSize() {
-                    Predicate<Customer> predicate = where().list(Customer::roles).hasSize(3);
+                    Predicate<Customer> predicate = where().list(Customer::roles).size().isEqualTo(3);
                     assertThat(predicate).rejects(new Customer(asList("Admin", "User"), null));
                 }
 
                 @Test
                 @DisplayName("mapped list is empty and size is not zero")
                 void mappedListIsEmptyAndSizeIsNotZero() {
-                    Predicate<Customer> predicate = where().list(Customer::roles).hasSize(1);
+                    Predicate<Customer> predicate = where().list(Customer::roles).size().isEqualTo(1);
                     assertThat(predicate).rejects(new Customer(new ArrayList<>(), null));
                 }
 
                 @Test
                 @DisplayName("mapped list is null and size is not zero")
                 void mappedListIsNullAndSizeIsNotZero() {
-                    Predicate<Customer> predicate = where().list(Customer::roles).hasSize(2);
+                    Predicate<Customer> predicate = where().list(Customer::roles).size().isEqualTo(2);
                     assertThat(predicate).rejects(new Customer(null, null));
                 }
             }
         }
 
         @Nested
-        @DisplayName(".notHaveSize(size)")
-        class NotHaveSize {
+        @DisplayName(".size().notEqualTo(size)")
+        class SizeNotEqualTo {
 
             @Nested
             @DisplayName("returns true when")
@@ -1285,21 +1285,21 @@ class ReturnsTrueWhen {
                 @Test
                 @DisplayName("mapped list does not have the specified size")
                 void mappedListDoesNotHaveSpecifiedSize() {
-                    Predicate<Customer> predicate = where().list(Customer::roles).notHaveSize(3);
+                    Predicate<Customer> predicate = where().list(Customer::roles).size().notEqualTo(3);
                     assertThat(predicate).accepts(new Customer(asList("Admin", "User"), null));
                 }
 
                 @Test
                 @DisplayName("mapped list is null and specified size is not zero")
                 void mappedListIsNullAndSpecifiedSizeIsNotZero() {
-                    Predicate<Customer> predicate = where().list(Customer::roles).notHaveSize(2);
+                    Predicate<Customer> predicate = where().list(Customer::roles).size().notEqualTo(2);
                     assertThat(predicate).accepts(new Customer(null, null));
                 }
 
                 @Test
                 @DisplayName("mapped list is empty and size is not zero")
                 void mappedListIsEmptyAndSizeIsNotZero() {
-                    Predicate<Customer> predicate = where().list(Customer::roles).notHaveSize(1);
+                    Predicate<Customer> predicate = where().list(Customer::roles).size().notEqualTo(1);
                     assertThat(predicate).accepts(new Customer(new ArrayList<>(), null));
                 }
             }
@@ -1311,21 +1311,21 @@ class ReturnsFalseWhen {
                 @Test
                 @DisplayName("mapped list has the specified size")
                 void mappedListHasSpecifiedSize() {
-                    Predicate<Customer> predicate = where().list(Customer::roles).notHaveSize(2);
+                    Predicate<Customer> predicate = where().list(Customer::roles).size().notEqualTo(2);
                     assertThat(predicate).rejects(new Customer(asList("Admin", "User"), null));
                 }
 
                 @Test
                 @DisplayName("mapped list is empty and specified size is zero")
                 void mappedListIsEmptyAndSpecifiedSizeIsZero() {
-                    Predicate<Customer> predicate = where().list(Customer::roles).notHaveSize(0);
+                    Predicate<Customer> predicate = where().list(Customer::roles).size().notEqualTo(0);
                     assertThat(predicate).rejects(new Customer(new ArrayList<>(), null));
                 }
 
                 @Test
                 @DisplayName("mapped list is null and specified size is zero")
                 void mappedListIsNullAndSpecifiedSizeIsZero() {
-                    Predicate<Customer> predicate = where().list(Customer::roles).notHaveSize(0);
+                    Predicate<Customer> predicate = where().list(Customer::roles).size().notEqualTo(0);
                     assertThat(predicate).rejects(new Customer(new ArrayList<>(), null));
                 }
             }