diff --git a/util/size_estimation.py b/util/size_estimation.py
new file mode 100644
index 0000000..2b9bab1
--- /dev/null
+++ b/util/size_estimation.py
@@ -0,0 +1,61 @@
+import sys, os
+sys.path.append(os.path.dirname(os.path.dirname(os.path.abspath(__file__))))
+from exllamav3 import Config, Model
+import argparse
+from exllamav3.loader.safetensors import SafetensorsCollection, VariantSafetensorsCollection
+import yaml
+
+
+def tsize(t):
+    return t.nelement() * t.element_size()
+
+
+def dsize(d):
+    size = 0
+    for _, v in d.items(): size += tsize(v)
+    return size
+
+
+def main(args):
+
+    # Config/model
+    config = Config.from_directory(args.in_dir)
+    model = Model.from_config(config)
+
+    # Tensor collection
+    stc = SafetensorsCollection(args.in_dir)
+
+    # Override tensors
+    if args.override:
+        with open(args.override, "r") as f:
+            comp = yaml.safe_load(f)
+        sources = {s["id"]: s["model_dir"] for s in comp["sources"]}
+        overrides = {o["key"]: sources[o["source"]] for o in comp["overrides"]}
+        collections = {}
+        for o_key, o_dir in overrides.items():
+            if o_dir not in collections:
+                collections[o_dir] = []
+            collections[o_dir].append(o_key)
+        if len(collections):
+            vstc = VariantSafetensorsCollection(config.stc)
+            for o_dir, o_keys in collections.items():
+                print(f" -- Overriding from: {o_dir}:")
+                for o_key in o_keys:
+                    print(f"      {o_key}")
+                vstc.add_stc(o_keys, SafetensorsCollection(o_dir))
+            config.stc = vstc
+
+    # New bpw etc.
+    bpw_layer, bpw_head, vram_bits = model.get_storage_info()
+    bpw_layer = round(bpw_layer, 2)
+    bpw_head = round(bpw_head)
+    print(f" -- New estimated model bitrate: {bpw_layer:.2f} bpw / {bpw_head:.2f} bpw (head)")
+    print(f" -- VRAM: {vram_bits / 8 / 1024**3:.0f} GiB")
+
+
+if __name__ == "__main__":
+    parser = argparse.ArgumentParser()
+    parser.add_argument("-i", "--in_dir", type = str, default = None, help = "Input model directory")
+    parser.add_argument("-or", "--override", type = str, help = "Tensor override spec (YAML)", default = None)
+    _args = parser.parse_args()
+    main(_args)