diff --git a/Source/YOChartImageKit/YOBarChartImage.h b/Source/YOChartImageKit/YOBarChartImage.h
index 0ebf1e6..6984775 100644
--- a/Source/YOChartImageKit/YOBarChartImage.h
+++ b/Source/YOChartImageKit/YOBarChartImage.h
@@ -29,6 +29,12 @@ typedef NS_ENUM(NSInteger, YOBarChartImageBarStyle){
  */
 @property (nonnull, nonatomic) NSArray<NSNumber *> *values;
 
+/**
+ *  The maximum value to use for the chart. Setting this will override the 
+ *  default behavior of using the highest value as maxValue.
+ */
+@property (nonnull, nonatomic) NSNumber* maxValue;
+
 /**
  *  The style of the bar chart.
  */
diff --git a/Source/YOChartImageKit/YOBarChartImage.m b/Source/YOChartImageKit/YOBarChartImage.m
index c03d9ac..d4c10d0 100644
--- a/Source/YOChartImageKit/YOBarChartImage.m
+++ b/Source/YOChartImageKit/YOBarChartImage.m
@@ -17,12 +17,16 @@ - (instancetype)init
     return self;
 }
 
+- (NSNumber *) maxValue {
+    return _maxValue ? _maxValue : [NSNumber numberWithFloat:[[_values valueForKeyPath:@"@max.floatValue"] floatValue]];
+}
+
 const CGFloat kBarPaddingMultipler = 20.0f;
 
 - (UIImage *)drawImage:(CGRect)frame scale:(CGFloat)scale {
     NSAssert(_values.count > 0, @"YOBarChartImage // must assign values property which is an array of NSNumber");
 
-    CGFloat maxValue = [[_values valueForKeyPath:@"@max.floatValue"] floatValue];
+    CGFloat maxValue = _maxValue ? [_maxValue floatValue] : [[_values valueForKeyPath:@"@max.floatValue"] floatValue];
     CGFloat dataCount = (CGFloat)_values.count;
 
     CGFloat padding;
diff --git a/Source/YOChartImageKit/YOLineChartImage.h b/Source/YOChartImageKit/YOLineChartImage.h
index b6a38ad..aa96f89 100644
--- a/Source/YOChartImageKit/YOLineChartImage.h
+++ b/Source/YOChartImageKit/YOLineChartImage.h
@@ -13,6 +13,12 @@
  */
 @property (nonnull, nonatomic) NSArray<NSNumber *> *values;
 
+/**
+ *  The maximum value to use for the chart. Setting this will override the
+ *  default behavior of using the highest value as maxValue.
+ */
+@property (nonnull, nonatomic) NSNumber* maxValue;
+
 /**
  *  The width of chart's stroke. 
  *  The default width is `1.0`.
diff --git a/Source/YOChartImageKit/YOLineChartImage.m b/Source/YOChartImageKit/YOLineChartImage.m
index 77f86c7..9317ada 100644
--- a/Source/YOChartImageKit/YOLineChartImage.m
+++ b/Source/YOChartImageKit/YOLineChartImage.m
@@ -12,13 +12,17 @@ - (instancetype)init {
     return self;
 }
 
+- (NSNumber *) maxValue {
+    return _maxValue ? _maxValue : [NSNumber numberWithFloat:[[_values valueForKeyPath:@"@max.floatValue"] floatValue]];
+}
+
 - (UIImage *)drawImage:(CGRect)frame scale:(CGFloat)scale {
     NSAssert(_values.count > 0, @"YOLineChartImage // must assign values property which is an array of NSNumber");
     
     NSUInteger valuesCount = _values.count;
     CGFloat pointX = frame.size.width / (valuesCount - 1);
     NSMutableArray<NSValue *> *points = [NSMutableArray array];
-    CGFloat maxValue = [[_values valueForKeyPath:@"@max.floatValue"] floatValue];
+    CGFloat maxValue = _maxValue ? [_maxValue floatValue] : [[_values valueForKeyPath:@"@max.floatValue"] floatValue];
 
     [_values enumerateObjectsUsingBlock:^(NSNumber *number, NSUInteger idx, BOOL *_) {
         CGFloat ratioY = number.floatValue / maxValue;