diff --git a/.eslintrc b/.eslintrc
index 9a5dac9..ff5e25c 100644
--- a/.eslintrc
+++ b/.eslintrc
@@ -14,6 +14,10 @@
     "node": true,
     "jest": true
   },
+  
+  "globals": {
+    "window": true
+  },
 
   "plugins": [
     "react",
diff --git a/README.md b/README.md
index 2df70b8..efa25d2 100644
--- a/README.md
+++ b/README.md
@@ -263,6 +263,45 @@ const styles = EStyleSheet.create({
   }
 });
 ```
+
+Here is an example of the orientation change:
+
+```js
+var styles = EStyleSheet.create({
+    card: {
+      height: 200,
+	  backgroundColor: 'green'
+    },
+    '@media all and (orientation: portrait)': {
+      card: {
+        width: '42%'
+      }
+    },
+    '@media all and (orientation: landscape)': {
+      card: {
+        width: '23%'
+      }
+    }
+});
+
+class example extends React.Component {
+	onLayoutChange(event){
+      var updatedStyles = EStyleSheet.orientationUpdate(event, styles); 
+      if(updatedStyles){
+        styles = updatedStyles;
+        this.forceUpdate();
+      }
+    }
+	
+	render() {
+      console.warn('render');
+      return (
+		<View onLayout={ this.onLayoutChange.bind(this) } style={styles.card}>...</View>
+	  )
+	}
+}
+```
+
 See full example [here](examples/media-queries).  
 \[[top](#)\]
 
diff --git a/src/__tests__/api.test.js b/src/__tests__/api.test.js
index 8713985..de5bfdb 100644
--- a/src/__tests__/api.test.js
+++ b/src/__tests__/api.test.js
@@ -120,4 +120,24 @@ describe('EStyleSheet API', function () {
     const fn = () => api.subscribe('build', null);
     expect(fn).toThrowError('Listener should be a function.');
   });
+  
+  it('should update styles in orientation change', function () {
+	api.build({});
+    let defaultStyles = api.create({
+      card: {
+        width: '50%',
+      }
+    });
+	
+	var layout = {nativeEvent:{layout:{width:50, height: 100}}};
+	let landscapeStyles = api.orientationUpdate(layout, defaultStyles); 
+	expect(defaultStyles).not.toEqual(landscapeStyles);
+	
+	layout = {nativeEvent:{layout:{width:100, height: 50}}};
+	let portraitStyles = api.orientationUpdate(layout, defaultStyles); 
+    expect(defaultStyles).toEqual(portraitStyles);
+	
+	let portraitStyles2 = api.orientationUpdate(layout, landscapeStyles); 
+    expect(portraitStyles2).toEqual(false);
+  });
 });
diff --git a/src/api.js b/src/api.js
index 9bab280..f5064f0 100644
--- a/src/api.js
+++ b/src/api.js
@@ -8,6 +8,8 @@ import Value from './value';
 import vars from './replacers/vars';
 import memoize from './memoize';
 import child from './child';
+import utils from './utils';
+
 
 const BUILD_EVENT = 'build';
 
@@ -37,9 +39,27 @@ export default class {
     } else {
       this.sheets.push(sheet);
     }
+    this._cacheSheetSource(sheet.getResult(), sheet);
+
     return sheet.getResult();
   }
 
+  /**
+   * Updates a specific stylesheet when the orientation changes
+   * @param {orientation} string
+   * @param {originalObj} obj
+   * @returns {Object}
+   */
+  orientationUpdate(event, originalObj) {
+    var dimensions = utils.setDimensions(event.nativeEvent.layout);
+    if(dimensions.updated == false){
+      return false;
+    }
+    var source = this._cacheSheetSource(originalObj);
+    let sheet = new Sheet(source);
+    sheet.calc(this.globalVars);
+    return sheet.getResult();
+  }
   /**
    * Builds all created stylesheets with passed variables
    * @param {Object} [gVars]
@@ -99,4 +119,17 @@ export default class {
       this.listeners[event].forEach(listener => listener());
     }
   }
+
+  _cacheSheetSource(key, sheet){
+    key = JSON.stringify(Object.keys(key));
+    if (!memoize.cache) {
+      memoize.cache = {};
+    }
+    if (!memoize.cache[key]) {
+      if(sheet){
+        memoize.cache[key] = sheet.source;
+      }
+    }
+    return memoize.cache[key];
+  }
 }
diff --git a/src/replacers/media-queries.js b/src/replacers/media-queries.js
index 4b0d1c1..5d68746 100644
--- a/src/replacers/media-queries.js
+++ b/src/replacers/media-queries.js
@@ -8,7 +8,7 @@
  * - aspect-ratio
  */
 
-import {Dimensions, Platform} from 'react-native';
+import {Platform} from 'react-native';
 import mediaQuery from 'css-mediaquery';
 import utils from '../utils';
 
@@ -64,11 +64,11 @@ function process(obj) {
  * @returns {Object}
  */
 function getMatchObject() {
-  const win = Dimensions.get('window');
+  const win = utils.getDimensions();
   return {
     width: win.width,
     height: win.height,
-    orientation: win.width > win.height ? 'landscape' : 'portrait',
+    orientation: win.orientation,
     'aspect-ratio': win.width / win.height,
     type: Platform.OS,
   };
diff --git a/src/replacers/percent.js b/src/replacers/percent.js
index d070a44..40afb84 100644
--- a/src/replacers/percent.js
+++ b/src/replacers/percent.js
@@ -1,10 +1,8 @@
 /**
  * Calculation of percent strings
  */
+import utils from '../utils';
 
-import {Dimensions} from 'react-native';
-
-const {width, height} = Dimensions.get('window');
 const V_PROPS = [
   'height',
   'top',
@@ -44,8 +42,9 @@ function isPercent(str) {
  * @returns {number}
  */
 function calc(str, prop) {
+  const win = utils.getDimensions();
   let percent = parseInt(str.substring(0, str.length - 1), 10);
-  let base = isVertical(prop) ? height : width;
+  let base = isVertical(prop) ? win.height : win.width;
   return base * percent / 100;
 }
 
diff --git a/src/utils.js b/src/utils.js
index e4d59ff..b0f3dd2 100644
--- a/src/utils.js
+++ b/src/utils.js
@@ -1,10 +1,13 @@
 /**
  * Utils
  */
+import {Dimensions} from 'react-native';
 
 export default {
   excludeKeys,
   isObject,
+  setDimensions,
+  getDimensions
 };
 
 /**
@@ -31,3 +34,27 @@ function excludeKeys(obj, keys) {
 function isObject(obj) {
   return typeof obj === 'object' && obj !== null;
 }
+
+function setDimensions(layout, defaultLayout){
+  defaultLayout = defaultLayout || false;
+  var updated = false;
+  if(!defaultLayout){
+    if(window.dimensions.width !== layout.width){
+      updated = true;
+    }
+  }
+  return window.dimensions = {
+    orientation: (layout.width < layout.height ? 'portrait' : 'landscape'),
+    width: layout.width,
+    height: layout.height,
+    default: defaultLayout,
+    updated: updated
+  }
+}
+
+function getDimensions(){
+  if(!window.dimensions){
+    setDimensions(Dimensions.get('window'), true);
+  }
+  return window.dimensions;
+}