1diff --git a/TODO.md b/TODO.md
  2index 05a283f..d130719 100644
  3--- a/TODO.md
  4+++ b/TODO.md
  5@@ -43,7 +43,6 @@ Many of these formulas can be written by allowing the Sheet and Parser to return
  6 
  7 
  8 ### Easy formulas to write
  9-* PROPER
 10 * REGEXEXTRACT - May be difficult considering language differences.
 11 * REGEXMATCH - May be difficult considering language differences.
 12 * REGEXREPLACE - May be difficult considering language differences.
 13diff --git a/dist/Formulas/AllFormulas.js b/dist/Formulas/AllFormulas.js
 14index 9a25942..c45d66e 100644
 15--- a/dist/Formulas/AllFormulas.js
 16+++ b/dist/Formulas/AllFormulas.js
 17@@ -237,6 +237,7 @@ exports.REPT = Text_1.REPT;
 18 exports.VALUE = Text_1.VALUE;
 19 exports.CLEAN = Text_1.CLEAN;
 20 exports.MID = Text_1.MID;
 21+exports.PROPER = Text_1.PROPER;
 22 var Date_1 = require("./Date");
 23 exports.DATE = Date_1.DATE;
 24 exports.DATEVALUE = Date_1.DATEVALUE;
 25diff --git a/dist/Formulas/Text.js b/dist/Formulas/Text.js
 26index e3d1aa0..e45322b 100644
 27--- a/dist/Formulas/Text.js
 28+++ b/dist/Formulas/Text.js
 29@@ -888,3 +888,11 @@ var MID = function (text, start, number) {
 30     return text.substring(start - 1, start + number - 1);
 31 };
 32 exports.MID = MID;
 33+var PROPER = function (text) {
 34+    ArgsChecker_1.ArgsChecker.checkLength(arguments, 1, "PROPER");
 35+    text = TypeConverter_1.TypeConverter.firstValueAsString(text);
 36+    return text.replace(/\w\S*/g, function (txt) {
 37+        return txt.charAt(0).toUpperCase() + txt.substr(1).toLowerCase();
 38+    });
 39+};
 40+exports.PROPER = PROPER;
 41diff --git a/src/Formulas/AllFormulas.ts b/src/Formulas/AllFormulas.ts
 42index d620625..e266c8a 100644
 43--- a/src/Formulas/AllFormulas.ts
 44+++ b/src/Formulas/AllFormulas.ts
 45@@ -244,7 +244,8 @@ import {
 46   REPT,
 47   VALUE,
 48   CLEAN,
 49-  MID
 50+  MID,
 51+  PROPER
 52 } from "./Text"
 53 import {
 54   DATE,
 55@@ -549,5 +550,6 @@ export {
 56   REPT,
 57   VALUE,
 58   CLEAN,
 59-  MID
 60+  MID,
 61+  PROPER
 62 }
 63\ No newline at end of file
 64diff --git a/src/Formulas/Text.ts b/src/Formulas/Text.ts
 65index 4de1a97..957d506 100644
 66--- a/src/Formulas/Text.ts
 67+++ b/src/Formulas/Text.ts
 68@@ -920,6 +920,15 @@ let MID = function (text, start, number) {
 69   return text.substring(start - 1, start + number - 1);
 70 };
 71 
 72+
 73+let PROPER = function (text) {
 74+  ArgsChecker.checkLength(arguments, 1, "PROPER");
 75+  text = TypeConverter.firstValueAsString(text);
 76+  return text.replace(/\w\S*/g, function(txt) {
 77+    return txt.charAt(0).toUpperCase() + txt.substr(1).toLowerCase();
 78+  });
 79+};
 80+
 81 export {
 82   ARABIC,
 83   CHAR,
 84@@ -942,5 +951,6 @@ export {
 85   REPT,
 86   VALUE,
 87   CLEAN,
 88-  MID
 89+  MID,
 90+  PROPER
 91 }
 92\ No newline at end of file
 93diff --git a/tests/Formulas/TextTest.ts b/tests/Formulas/TextTest.ts
 94index e46266a..f5c98e5 100644
 95--- a/tests/Formulas/TextTest.ts
 96+++ b/tests/Formulas/TextTest.ts
 97@@ -20,7 +20,8 @@ import {
 98   REPT,
 99   VALUE,
100   CLEAN,
101-  MID
102+  MID,
103+  PROPER
104 } from "../../src/Formulas/Text";
105 import * as ERRORS from "../../src/Errors";
106 import {
107@@ -538,3 +539,18 @@ test("MID", function(){
108     MID.apply(this, [1, 2]);
109   }, ERRORS.NA_ERROR);
110 });
111+
112+test("PROPER", function(){
113+  assertEquals(PROPER("hey there"), "Hey There");
114+  assertEquals(PROPER("hEY tHERE"), "Hey There");
115+  assertEquals(PROPER("there once was a man, and he lived on the moon."), "There Once Was A Man, And He Lived On The Moon.");
116+  assertEquals(PROPER("my name is h.s. thompson"), "My Name Is H.s. Thompson");
117+  assertEquals(PROPER(true), "True");
118+  assertEquals(PROPER(10), "10");
119+  catchAndAssertEquals(function () {
120+    PROPER.apply(this, []);
121+  }, ERRORS.NA_ERROR);
122+  catchAndAssertEquals(function () {
123+    PROPER.apply(this, [1, 2]);
124+  }, ERRORS.NA_ERROR);
125+});
126diff --git a/tests/SheetFormulaTest.ts b/tests/SheetFormulaTest.ts
127index 899d77c..65d1f1d 100644
128--- a/tests/SheetFormulaTest.ts
129+++ b/tests/SheetFormulaTest.ts
130@@ -1085,6 +1085,10 @@ test("Sheet MID", function(){
131   assertFormulaEquals('=MID("hey there", 5, 4)', "ther");
132 });
133 
134+test("Sheet PROPER", function(){
135+  assertFormulaEquals('=PROPER("hey there")', "Hey There");
136+});
137+
138 test("Sheet parsing error", function(){
139   assertFormulaEqualsError('= 10e', PARSE_ERROR);
140   assertFormulaEqualsError('= SUM(', PARSE_ERROR);