diff --git a/map.py b/map.py
index 1382ae6..aa3067c 100644
--- a/map.py
+++ b/map.py
@@ -167,20 +167,14 @@ def main():
     #         math.degrees(2 * math.atan(math.exp(y / zoom_scale)) - math.pi / 2.)
     #     )
 
-    map_width = 0
-    map_height = 0
-    min_x = 0
-    max_y = 0
-    for zoom_level in range(50):
-        zoom_scale = 2**zoom_level / 2 * math.pi
-        min_x, min_y = get_map_raw_coords(bounds.minlon, bounds.minlat)
-        max_x, max_y = get_map_raw_coords(bounds.maxlon, bounds.maxlat)
-        map_width = max_x - min_x
-        if map_width >= map_target_width:
-            map_height = abs(max_y - min_y)
-            break
+    zoom_level = 1 + int(-math.log2(((bounds.maxlon - bounds.minlon) * 2 * math.pi) / map_target_width))
+    zoom_scale = (2**zoom_level * map_target_width) / (2 * math.pi)
+    min_x, min_y = get_map_raw_coords(bounds.minlon, bounds.minlat)
+    max_x, max_y = get_map_raw_coords(bounds.maxlon, bounds.maxlat)
+    map_width = max_x - min_x
+    map_height = max_y - min_y
 
-    assert map_width > 0 and 0 < map_height < map_width * 3
+    assert map_width > 0 and 0 < map_height < map_width * 10
 
     def get_map_coords(lon: float, lat: float) -> tuple[int, int]:
         nonlocal min_x, max_y