diff --git a/README.md b/README.md
index da0bec6..feab2bd 100644
--- a/README.md
+++ b/README.md
@@ -15,6 +15,7 @@ pip install -e .
 ```
 
 ## Overview
+
 Columbus.pdf contains a overview of columbus.
 
 ## Layout of the Repo
@@ -27,6 +28,7 @@ There exist two ways to implement new envs:
 
 - Subclassing ColumbusEnv and expanding _init_ and overriding _setup_.
 - Using the ColumbusConfigDefined with a desired configuration. This makes configuring ColumbusEnvs via ClusterWorks2-configs possible. (See configs/example.yaml for an example of how the parameters are supposed to look like (uses yaml format)
+- We now support using units (px, em, ct) in config files, examples can be found in configs/Example_Units.yaml
 - The environments used in my thesis can also be found in configs/
 
 ##### Some caveats / infos
diff --git a/columbus/env.py b/columbus/env.py
index c76aea1..1814915 100644
--- a/columbus/env.py
+++ b/columbus/env.py
@@ -839,6 +839,45 @@ class ColumbusConfigDefined(ColumbusEnv):
             observable=observable, fps=fps, env_seed=env_seed, **kw)
         self.entities_definitions = entities
 
+    def is_unit(self, s):
+        if type(s) in [int, float]:
+            return True
+        if s.replace('.', '', 1).isdigit():
+            return True
+        num, unit = s[:-2], s[-2:]
+        if unit in ['px', 'em', 'rx', 'ry', 'ct']:
+            if num.replace('.', '', 1).isdigit():
+                return True
+        return False
+
+    def conv_unit(self, s, target='px', axis='x'):
+        assert self.is_unit(s)
+        if type(s) in [int, float]:
+            return s
+        if s.replace('.', '', 1).isdigit():
+            return float(s)
+        num, unit = s[:-2], s[-2:]
+        num = float(num)
+        if unit == 'rx':
+            unit = 'px'
+            axis = 'x'
+        elif unit == 'ry':
+            unit = 'px'
+            axis = 'y'
+        if unit == 'em':
+            em = num
+        elif unit == 'px':
+            em = num / ({'x': self.width, 'y': self.height}[axis])
+        elif unit == 'ct':
+            em = num / 100
+        else:
+            raise Exception('Conversion not implemented')
+
+        if target == 'em':
+            return em
+        elif target == 'px':
+            return em * ({'x': self.width, 'y': self.height}[axis])
+
     def setup(self):
         self.agent.pos = self.start_pos
         for i, e in enumerate(self.entities_definitions):
@@ -848,7 +887,15 @@ class ColumbusConfigDefined(ColumbusEnv):
                 conf = {k: v for k, v in e.items() if str(
                     k) not in ['num', 'num_rand', 'type']}
 
-                for k, v in conf.items():
+                for k, v_raw in conf.items():
+                    if k == 'pos':
+                        v = self.conv_unit(v_raw[0], target='em', axis='x'), self.conv_unit(
+                            v_raw[1], target='em', axis='y')
+                    elif k in ['width', 'height', 'radius']:
+                        v = self.conv_unit(
+                            v_raw, target='px', axis='y' if k == 'height' else 'x')
+                    else:
+                        v = v_raw
                     if k.endswith('_rand'):
                         n = k.replace('_rand', '')
                         cur = getattr(
diff --git a/configs/Example_Units.yaml b/configs/Example_Units.yaml
new file mode 100644
index 0000000..14c005e
--- /dev/null
+++ b/configs/Example_Units.yaml
@@ -0,0 +1,85 @@
+name: "DEFAULT"
+
+# Supported Units:
+# px: Pixels
+# em: 1em = Full Width / Height
+# ct: 100ct = Full Width / Height
+# rx: pixels relative to width
+# ry: pixels relative to height
+#
+# When no unit is given, we use the folowing defaults
+# (compatible with legacy behavior)
+# pos: em
+# all other: px
+#
+# ct is the recommendet unit...
+
+params:
+  task:
+    task: columbus
+    env_name: ColumbusConfigDefined-v0
+    env_args:
+      observable:
+        - type: State
+          coordsAgent: True
+          speedAgent: True
+          coordsRelativeToAgent: False
+          coordsRewards: True
+          coordsEnemys: False
+          enemysNoBarriers: True
+          rewardsTimeouts: False
+          include_rand: True
+        - type: State
+          coordsAgent: False
+          speedAgent: False
+          coordsRelativeToAgent: True
+          coordsRewards: True
+          coordsEnemys: False
+          enemysNoBarriers: True
+          rewardsTimeouts: False
+          include_rand: True
+        - type: Compass
+        - type: RayCast
+          num_rays: 6
+          chans: [Enemy]
+      entities:
+        - type: RectBarrier
+          num: 1
+          width: 50ct
+          height: 50ct
+          pos: [0ct, 0ct]
+        - type: RectBarrier
+          num: 1
+          width: 50ct
+          height: 50ct
+          pos: [50ct, 50ct]
+        - type: RectBarrier
+          num: 1
+          width: 25rx
+          height: 25ry
+          pos: [0.75em, 30px]
+        - type: RectBarrier
+          num: 1
+          width: 25ry
+          height: 25rx
+          pos: [0.75em, 60px]
+        - type: OnceReward
+          reward: 100
+          radius: 3ct
+          pos: [0.3, 0.8]
+      start_pos: [0.1, 0.21]
+      default_collision_elasticity: 0.8
+      start_score: 10
+      speed_fac: 0.01
+      acc_fac: 0.1
+      die_on_zero: False #True
+      agent_drag: 0.1 # 0.05
+      controll_type: ACC # SPEED
+      aux_reward_max: 1
+      aux_penalty_max: 0.01
+      void_damage: 5 #1
+      terminate_on_reward: True
+      agent_draw_path: True
+      clear_path_on_reset: False
+      max_steps: 450 # 1800
+---
\ No newline at end of file