diff --git a/modules/processing.py b/modules/processing.py
index 02441d7b..a8ce9831 100644
--- a/modules/processing.py
+++ b/modules/processing.py
@@ -1186,14 +1186,14 @@ def process_extra_images(processed: Processed):
     processed.extra_images = extra_images
 
 
-def old_hires_fix_first_pass_dimensions(width, height):
+def old_hires_fix_first_pass_dimensions(width: int, height: int) -> tuple[int, int]:
     """old algorithm for auto-calculating first pass size"""
 
     desired_pixel_count = 512 * 512
     actual_pixel_count = width * height
     scale = math.sqrt(desired_pixel_count / actual_pixel_count)
-    width = math.ceil(scale * width / 64) * 64
-    height = math.ceil(scale * height / 64) * 64
+    width = round(scale * width / 64.0) * 64
+    height = round(scale * height / 64.0) * 64
 
     return width, height
 
@@ -1261,32 +1261,23 @@ class StableDiffusionProcessingTxt2Img(StableDiffusionProcessing):
 
         if self.hr_resize_x == 0 and self.hr_resize_y == 0:
             self.extra_generation_params["Hires upscale"] = self.hr_scale
-            self.hr_upscale_to_x = int(self.width * self.hr_scale)
-            self.hr_upscale_to_y = int(self.height * self.hr_scale)
+            self.hr_upscale_to_x = round(self.width * self.hr_scale / 64.0) * 64
+            self.hr_upscale_to_y = round(self.height * self.hr_scale / 64.0) * 64
         else:
-            self.extra_generation_params["Hires resize"] = f"{self.hr_resize_x}x{self.hr_resize_y}"
-
             if self.hr_resize_y == 0:
                 self.hr_upscale_to_x = self.hr_resize_x
-                self.hr_upscale_to_y = self.hr_resize_x * self.height // self.width
+                self.hr_upscale_to_y = self.hr_resize_x * (self.height / self.width)
             elif self.hr_resize_x == 0:
-                self.hr_upscale_to_x = self.hr_resize_y * self.width // self.height
+                self.hr_upscale_to_x = self.hr_resize_y * (self.width / self.height)
                 self.hr_upscale_to_y = self.hr_resize_y
             else:
-                target_w = self.hr_resize_x
-                target_h = self.hr_resize_y
-                src_ratio = self.width / self.height
-                dst_ratio = self.hr_resize_x / self.hr_resize_y
+                self.hr_upscale_to_x = self.hr_resize_x
+                self.hr_upscale_to_y = self.hr_resize_y
 
-                if src_ratio < dst_ratio:
-                    self.hr_upscale_to_x = self.hr_resize_x
-                    self.hr_upscale_to_y = self.hr_resize_x * self.height // self.width
-                else:
-                    self.hr_upscale_to_x = self.hr_resize_y * self.width // self.height
-                    self.hr_upscale_to_y = self.hr_resize_y
+            self.hr_upscale_to_x = round(self.hr_upscale_to_x / 64.0) * 64
+            self.hr_upscale_to_y = round(self.hr_upscale_to_y / 64.0) * 64
 
-                self.truncate_x = (self.hr_upscale_to_x - target_w) // opt_f
-                self.truncate_y = (self.hr_upscale_to_y - target_h) // opt_f
+            self.extra_generation_params["Hires resize"] = f"{self.hr_upscale_to_x}x{self.hr_upscale_to_y}"
 
     @staticmethod
     def get_hr_prompt(p, index, prompt_text, **kwargs):