1diff --git a/src/RawFormulas/RawFormulas.ts b/src/RawFormulas/RawFormulas.ts
  2index c45bcca..3e0c3a2 100644
  3--- a/src/RawFormulas/RawFormulas.ts
  4+++ b/src/RawFormulas/RawFormulas.ts
  5@@ -119,7 +119,6 @@ var EOMONTH = function (start_date, months) {
  6   var edate = moment(start_date).add(months, 'months');
  7   return new Date(edate.year(), edate.month(), edate.daysInMonth());
  8 };
  9-var ERF = Formula["ERF"];
 10 var ERFC = Formula["ERFC"];
 11 var EXPONDIST = Formula["EXPONDIST"];
 12 var __COMPLEX = {
 13@@ -129,6 +128,61 @@ var __COMPLEX = {
 14 var YEARFRAC = Formula["YEARFRAC"];
 15 
 16 
 17+/**
 18+ * Returns the error function integrated between lower_limit and upper_limit.
 19+ * @param values[0] lower_limit - The lower bound for integrating ERF.
 20+ * @param values[1] upper_limit - [Optional]. The upper bound for integrating ERF. If omitted, ERF integrates between
 21+ * zero and lower_limit.
 22+ * @returns {number} error function integrated between lower_limit and upper_limit
 23+ * @constructor
 24+ */
 25+var ERF = function (...values) : number {
 26+  ArgsChecker.checkLengthWithin(values, 1, 2);
 27+  var lower = TypeCaster.firstValueAsNumber(values[0]);
 28+  var upper = values.length === 2 ? TypeCaster.firstValueAsNumber(values[1]) : 0;
 29+
 30+  // erf function from jStat [http://www.jstat.org/]
 31+  function erf(x) {
 32+    var cof = [-1.3026537197817094, 6.4196979235649026e-1, 1.9476473204185836e-2,
 33+      -9.561514786808631e-3, -9.46595344482036e-4, 3.66839497852761e-4,
 34+      4.2523324806907e-5, -2.0278578112534e-5, -1.624290004647e-6,
 35+      1.303655835580e-6, 1.5626441722e-8, -8.5238095915e-8,
 36+      6.529054439e-9, 5.059343495e-9, -9.91364156e-10,
 37+      -2.27365122e-10, 9.6467911e-11, 2.394038e-12,
 38+      -6.886027e-12, 8.94487e-13, 3.13092e-13,
 39+      -1.12708e-13, 3.81e-16, 7.106e-15,
 40+      -1.523e-15, -9.4e-17, 1.21e-16,
 41+      -2.8e-17];
 42+    var j = cof.length - 1;
 43+    var isneg = false;
 44+    var d = 0;
 45+    var dd = 0;
 46+    var t, ty, tmp, res;
 47+
 48+    if (x < 0) {
 49+      x = -x;
 50+      isneg = true;
 51+    }
 52+
 53+    t = 2 / (2 + x);
 54+    ty = 4 * t - 2;
 55+
 56+    for(; j > 0; j--) {
 57+      tmp = d;
 58+      d = ty * d - dd + cof[j];
 59+      dd = tmp;
 60+    }
 61+
 62+    res = t * Math.exp(-x * x + 0.5 * (cof[0] + ty * d) - dd);
 63+    return isneg ? res - 1 : 1 - res;
 64+  }
 65+
 66+  return values.length === 1 ? erf(lower) : erf(upper) - erf(lower);
 67+
 68+};
 69+
 70+
 71+
 72 /**
 73  * Calculates the depreciation of an asset for a specified period using the double-declining balance method.
 74  * @param values[0] cost - The initial cost of the asset.
 75diff --git a/tests/FormulasTest.ts b/tests/FormulasTest.ts
 76index e43a062..3fd8931 100644
 77--- a/tests/FormulasTest.ts
 78+++ b/tests/FormulasTest.ts
 79@@ -884,7 +884,25 @@ assertEquals(EFFECT(0.99, 12), 1.5890167507927795);
 80 
 81 assertEqualsDates(EOMONTH(DATE(1992, 6, 24), 1), new Date('7/31/1992'));
 82 
 83+
 84+// Test ERF
 85 assertEquals(ERF(2), 0.9953222650189527);
 86+assertEquals(ERF("2"), 0.9953222650189527);
 87+assertEquals(ERF(0), 1.1102230246251565e-16);
 88+assertEquals(ERF(1), 0.8427007929497149);
 89+assertEquals(ERF(true), 0.8427007929497149);
 90+assertEquals(ERF(false), 1.1102230246251565e-16);
 91+catchAndAssertEquals(function() {
 92+  ERF();
 93+}, ERRORS.NA_ERROR);
 94+catchAndAssertEquals(function() {
 95+  ERF([]);
 96+}, ERRORS.REF_ERROR);
 97+assertEquals(ERF(1, 2), 0.15262147206923782);
 98+assertEquals(ERF(2, 1), -0.15262147206923782);
 99+
100+
101+
102 
103 assertEquals(ERFC(2), 0.004677734981047288);
104