diff --git a/README.md b/README.md
index 62c52e6..3894681 100644
--- a/README.md
+++ b/README.md
@@ -18,6 +18,8 @@ Utopia Core SCSS outputs in two formats: mixins & functions. Mixins generate act
 
 All mixins/functions default `relativeTo` to `viewport` (`vi`), but can be overriden to `container` (`cqi`), or `viewport-width` (`vw`).
 
+All mixins/functions also default to a base unit of `0.0625rem` for pixel to relative unit conversions. Change this with the `baseUnit` if you have altered the root font size. For instance, setting the root font size to `62.5%` will, given default browser setting, set `1rem` to the equivalent of `10px`. To correct this in Utopia you will then have to set `baseUnit` to `0.1rem` (or whatever the relative size will result in `1px` size).
+
 ## Mixins
 
 ### `generateTypeScale()`
@@ -40,6 +42,7 @@ Generate a fluid type scale between two widths, sizes and scales. Set the number
     "negativeSteps": 2,
     /* Optional params */
     "relativeTo": "viewport",
+    "baseUnit": 0.1rem,
     "prefix": "step-",
   ));
 
@@ -72,6 +75,7 @@ Generate a set of fluid spaces from min/max width/base sizes, and a number of po
     "customSizes": ("s-l",),
     "usePx": true,
     "relativeTo": "container",
+    "baseUnit": 0.1rem,
     "prefix": "space-",
     "allPairs": false,
   ));
@@ -113,6 +117,7 @@ Generate multiple clamps from a single set of min/max widths. Supply an array of
     /* Optional params */
     "usePx": true,
     "relativeTo": "container",
+    "baseUnit": 0.1rem,
     "prefix": "space-",
   ))
 
@@ -139,6 +144,7 @@ Generate a single clamp custom property from a min/max width & size. Default to
     /* Optional params */
     "usePx": true,
     "relativeTo": "container",
+    "baseUnit": 0.1rem,
     "prefix": "space-",
   ))
 
@@ -167,6 +173,7 @@ $typeScale: utopia.calculateTypeScale((
   "negativeSteps": 2,
   /* Optional params */
   "relativeTo": "container",
+  "baseUnit": 0.1rem,
 ))
 
 // $typeScale == (
@@ -196,6 +203,7 @@ $spaceScales: utopia.calculateSpaceScale((
   "customSizes": ("s-l", "l-s",),
   /* Optional params */
   "relativeTo": "container",
+  "baseUnit": 0.1rem,
 ))
 
 // $spaceScales == (
@@ -230,7 +238,8 @@ $clamps: utopia.calculateClamps((
   ),
   /* Optional params */
   "usePx": true,
-  "relativeTo": "container"
+  "relativeTo": "container",
+  "baseUnit": 0.1rem,
 ))
 
 // $clamps == (
@@ -259,10 +268,9 @@ $clamp: utopia.calculateClamp((
   "maxSize": 48,
   /* Optional params */
   "usePx": true,
-  "relativeTo": "container"
+  "relativeTo": "container",
+  "baseUnit": 0.1rem,
 ))
 
 // clamp(1rem, 0.3043rem + 3.4783vi, 3rem);
 ```
-
-
diff --git a/src/utopia.scss b/src/utopia.scss
index 3c6cf79..f0cf3ce 100644
--- a/src/utopia.scss
+++ b/src/utopia.scss
@@ -8,7 +8,7 @@
 // Singular clamp
 
 @function calculateClamp($params) {
-  $unit: 0.0625rem;
+  $unit: helpers.getDefault($params, "baseUnit", 0.0625rem);
   @if (map.get($params, "usePx")) {
     $unit: 1px;
   }
@@ -52,6 +52,7 @@
     "minSize": $minSize,
     "maxSize": $maxSize,
     "clamp": calculateClamp((
+      "baseUnit": map.get($config, "baseUnit"),
       "minWidth": map.get($config, "minWidth"),
       "maxWidth": map.get($config, "maxWidth"),
       "minSize": $minSize,
@@ -190,7 +191,7 @@
       $pairs: list.append($pairs, calculateSpacePair($config, $a, $b));
     }
   }
-  
+
   @return $pairs;
 }
 
@@ -274,7 +275,7 @@
     @each $size in map.get($scale, "oneUpPairs") {
       --#{$prefix}#{map.get($size, "label")}: #{map.get($size, $format)};
     }
-  
+
     @each $size in map.get($scale, "customPairs") {
       --#{$prefix}#{map.get($size, "label")}: #{map.get($size, $format)};
     }