diff --git a/README.md b/README.md
index f67a27b..39693c4 100644
--- a/README.md
+++ b/README.md
@@ -11,7 +11,7 @@ versions, can increment versions, etc.
 
 Versions used with go-version must follow [SemVer](http://semver.org/).
 
-## Installation and Usage
+# Installation and Usage
 
 Package documentation can be found on
 [GoDoc](http://godoc.org/github.com/6543/go-version).
@@ -22,7 +22,7 @@ Installation can be done with a normal `go get`:
 $ go get github.com/6543/go-version
 ```
 
-#### Version Parsing and Comparison
+# Version Parsing and Comparison
 
 ```go
 v1, err := version.NewVersion("1.2")
@@ -35,7 +35,7 @@ if v1.LessThan(v2) {
 }
 ```
 
-#### Version Constraints
+# Version Constraints
 
 ```go
 v1, err := version.NewVersion("1.2")
@@ -45,9 +45,38 @@ constraints, err := version.NewConstraint(">= 1.0, < 1.4")
 if constraints.Check(v1) {
 	fmt.Printf("%s satisfies constraints %s", v1, constraints)
 }
+
+### Tilde Range Comparisons (Patch)
+
+The tilde (`~`) comparison operator is for patch level ranges when a minor
+version is specified and major level changes when the minor number is missing.
+For example,
+
+* `~1.2.3` is equivalent to `>= 1.2.3, < 1.3.0`
+* `~1` is equivalent to `>= 1, < 2`
+* `~2.3` is equivalent to `>= 2.3, < 2.4`
+* `~1.2.x` is equivalent to `>= 1.2.0, < 1.3.0`
+* `~1.x` is equivalent to `>= 1, < 2`
+
+### Caret Range Comparisons (Major)
+
+The caret (`^`) comparison operator is for major level changes once a stable
+(1.0.0) release has occurred. Prior to a 1.0.0 release the minor versions acts
+as the API stability level. This is useful when comparisons of API versions as a
+major change is API breaking. For example,
+
+* `^1.2.3` is equivalent to `>= 1.2.3, < 2.0.0`
+* `^1.2.x` is equivalent to `>= 1.2.0, < 2.0.0`
+* `^2.3` is equivalent to `>= 2.3, < 3`
+* `^2.x` is equivalent to `>= 2.0.0, < 3`
+* `^0.2.3` is equivalent to `>=0.2.3 <0.3.0`
+* `^0.2` is equivalent to `>=0.2.0 <0.3.0`
+* `^0.0.3` is equivalent to `>=0.0.3 <0.0.4`
+* `^0.0` is equivalent to `>=0.0.0 <0.1.0`
+* `^0` is equivalent to `>=0.0.0 <1.0.0`
 ```
 
-#### Version Sorting
+# Version Sorting
 
 ```go
 versionsRaw := []string{"1.1", "0.7.1", "1.4-beta", "1.4", "2"}
@@ -61,7 +90,7 @@ for i, raw := range versionsRaw {
 sort.Sort(version.Collection(versions))
 ```
 
-## Issues and Contributing
+# Issues and Contributing
 
 If you find an issue with this library, please report an issue. If you'd
 like, we welcome any contributions. Fork this library and submit a pull
diff --git a/constraint.go b/constraint.go
index a2f638d..6d7ad2e 100644
--- a/constraint.go
+++ b/constraint.go
@@ -35,6 +35,8 @@ func init() {
 		">=": constraintGreaterThanEqual,
 		"<=": constraintLessThanEqual,
 		"~>": constraintPessimistic,
+		"^":  constraintCaret,
+		"~":  constraintTilde,
 	}
 
 	ops := make([]string, 0, len(constraintOperators))
@@ -197,3 +199,31 @@ func constraintPessimistic(v, c *Version) bool {
 	// be valid against the constraint
 	return c.segments[cs-1] <= v.segments[cs-1]
 }
+
+func constraintCaret(v, c *Version) bool {
+	if !prereleaseCheck(v, c) || v.LessThan(c) {
+		return false
+	}
+
+	if v.segments[0] != c.segments[0] {
+		return false
+	}
+
+	return true
+}
+
+func constraintTilde(v, c *Version) bool {
+	if !prereleaseCheck(v, c) || v.LessThan(c) {
+		return false
+	}
+
+	if v.segments[0] != c.segments[0] {
+		return false
+	}
+
+	if c.si > 1 && v.segments[1] != c.segments[1] {
+		return false
+	}
+
+	return true
+}
diff --git a/constraint_test.go b/constraint_test.go
index d3721dc..6d1479e 100644
--- a/constraint_test.go
+++ b/constraint_test.go
@@ -75,6 +75,45 @@ func TestConstraintCheck(t *testing.T) {
 		{">= 2.1.0-a", "2.1.1-beta", false},
 		{">= 2.1.0-a", "2.1.0", true},
 		{"<= 2.1.0-a", "2.0.0", true},
+		{"^1.1", "1.1.1", true},
+		{"^1.1", "1.2.3", true},
+		{"^1.1", "2.1.0", false},
+		{"^1.1.2", "1.1.1", false},
+		{"^1.1.2", "1.1.2", true},
+		{"^1.1.2", "1.1.2.3", true},
+		{"~1", "1.3.5", true},
+		{"~1", "2.1.0", false},
+		{"~1.1", "1.1.1", true},
+		{"~1.1", "1.2.3", false},
+		{"~1.1.2", "1.1.1", false},
+		{"~1.1.2", "1.1.2", true},
+		{"~1.1.2", "1.1.2.5", true},
+		{"~1.1.2", "1.1.2.3", true},
+		{"^1.0.0", "1.0.0", true},
+		{"^1.0.0", "1.0.1", true},
+		{"^1.0.0", "1.9.1", true},
+		{"^1.0.0", "2.0.0", false},
+		{"^0.1.0", "0.1.0", true},
+		{"^0.1.0", "0.2.0", true},
+		{"^0.1.0", "0.3.0", true},
+		{"^0.1.0", "0.1.4", true},
+		{"^0.0.1", "0.0.0", false},
+		{"^0.0.1", "0.0.1", true},
+		{"^0.0.1", "0.0.2", true},
+		{"^0.0.1", "0.2.0", true},
+		{"^1.2.3", "1.99.99", true},
+		{"^1.2.3", "2.00.00", false},
+		{"~1.0.0", "1.0.0", true},
+		{"~1.0.0", "1.0.1", true},
+		{"~1.0.0", "1.9.1", false},
+		{"~1.0.0", "2.0.0", false},
+		{"~0.1.0", "0.1.0", true},
+		{"~0.1.0", "0.2.0", false},
+		{"~0.1.0", "0.1.4", true},
+		{"~0.0.1", "0.0.0", false},
+		{"~0.0.1", "0.0.1", true},
+		{"~0.0.1", "0.0.2", true},
+		{"~0.0.1", "0.2.0", false},
 	}
 
 	for _, tc := range cases {
@@ -91,7 +130,7 @@ func TestConstraintCheck(t *testing.T) {
 		actual := c.Check(v)
 		expected := tc.check
 		if actual != expected {
-			t.Fatalf("Version: %s\nConstraint: %s\nExpected: %#v",
+			t.Fatalf("\nVersion: %s\nConstraint: %s\nExpected: %#v",
 				tc.version, tc.constraint, expected)
 		}
 	}