diff --git a/include/arena.h b/include/arena.h
index 18a9470..b55c4c1 100644
--- a/include/arena.h
+++ b/include/arena.h
@@ -36,6 +36,14 @@ typedef struct {
     };
 } ArenaResult;
 
+typedef struct {
+    bool is_valid;
+    union {
+        ArenaErr err;
+        size_t val;
+    };
+} SizeResult;
+
 ArenaResult arena_init(size_t size);
 void arena_destroy(Arena *arena);
 
@@ -43,6 +51,7 @@ ArenaPointer arena_alloc(Arena *arena, size_t size, size_t alignment);
 ArenaErr arena_push(Arena *arena, void *data, size_t size, size_t alignment);
 ArenaErr arena_realloc(Arena *arena, size_t new_size);
 
-size_t align_arena_offset(Arena *arena, size_t alignment);
+SizeResult align_arena_offset(Arena *arena, size_t alignment);
+SizeResult arena_compute_necessary_capacity(size_t capacity, size_t elem_size);
 
 #endif // !ARENA_H
diff --git a/src/arena.c b/src/arena.c
index f084b39..4022d62 100644
--- a/src/arena.c
+++ b/src/arena.c
@@ -55,8 +55,16 @@ ArenaPointer arena_alloc(Arena *arena, size_t size, size_t alignment) {
         return err;
     }
 
-    size_t new_offset = align_arena_offset(arena, alignment);
-    if (new_offset + size >= arena->size) {
+    SizeResult new_offset = align_arena_offset(arena, alignment);
+    if (!new_offset.is_valid) {
+        ArenaPointer err = {
+            .is_valid = false,
+            .err = new_offset.err,
+        };
+        return err;
+    }
+
+    if (new_offset.val + size >= arena->size) {
         ArenaPointer err = {
             .is_valid = false,
             .err = ARENA_OUT_OF_SPACE,
@@ -64,7 +72,7 @@ ArenaPointer arena_alloc(Arena *arena, size_t size, size_t alignment) {
         return err;
     }
 
-    arena->offset = new_offset;
+    arena->offset = new_offset.val;
 
     ArenaPointer val = {
         .is_valid = true,
@@ -81,13 +89,18 @@ ArenaErr arena_push(Arena *arena, void *data, size_t size, size_t alignment) {
     ArenaPointer pointer = arena_alloc(arena, size, alignment);
 
     if (!pointer.is_valid) {
-        size_t new_size = arena->size * 2;
-        ArenaErr err = arena_realloc(arena, new_size);
+        SizeResult new_size = arena_compute_necessary_capacity(arena->size, size);
+        if (!new_size.is_valid) {
+            return new_size.err;
+        }
+
+        ArenaErr err = arena_realloc(arena, new_size.val);
         if (err != ARENA_OK) {
             return err;
         }
-    }
 
+        pointer = arena_alloc(arena, size, alignment);
+    }
 
     memcpy(
         pointer.address,
@@ -111,3 +124,5 @@ ArenaErr arena_realloc(Arena *arena, size_t new_size) {
     arena->size = new_size;
     return ARENA_OK;
 }
+
+