1diff --git a/src/RawFormulas/RawFormulas.ts b/src/RawFormulas/RawFormulas.ts
  2index d17701a..1e075cb 100644
  3--- a/src/RawFormulas/RawFormulas.ts
  4+++ b/src/RawFormulas/RawFormulas.ts
  5@@ -128,11 +128,49 @@ var __COMPLEX = {
  6   "F.DIST": Formula["FDIST"],
  7   "F.INV": Formula["FINV"]
  8 };
  9-var SUMPRODUCT = Formula["SUMPRODUCT"];
 10 var SUMX2MY2 = Formula["SUMX2MY2"];
 11 var SUMX2PY2 = Formula["SUMX2PY2"];
 12 var YEARFRAC = Formula["YEARFRAC"];
 13 
 14+/**
 15+ * Calculates the sum of the products of corresponding entries in two equal-sized arrays or ranges.
 16+ * @param values Arrays or ranges whose entries will be multiplied with corresponding entries in the second such array
 17+ * or range.
 18+ * @returns {number} sum of the products
 19+ * @constructor
 20+ */
 21+var SUMPRODUCT = function (...values) : number {
 22+  ArgsChecker.checkAtLeastLength(values, 1);
 23+  // Ensuring that all values are array values
 24+  for (var x = 0; x < values.length; x++) {
 25+    if (!Array.isArray(values[x])) {
 26+      values[x] = [values[x]];
 27+    }
 28+  }
 29+
 30+  // Flatten any nested ranges (arrays) and check for mismatched range sizes
 31+  var flattenedValues = [Filter.flattenAndThrow(values[0])];
 32+  for (var x = 1; x < values.length; x++) {
 33+    flattenedValues.push(Filter.flattenAndThrow(values[x]));
 34+    if (flattenedValues[x].length !== flattenedValues[0].length) {
 35+      throw new CellError(ERRORS.VALUE_ERROR, "SUMPRODUCT has mismatched range sizes. Expected count: "
 36+        + flattenedValues[0].length + ". Actual count: " + flattenedValues[0].length + ".");
 37+    }
 38+  }
 39+
 40+  // Do the actual math
 41+  var result = 0;
 42+  for (var i = 0; i < flattenedValues[0].length; i++) {
 43+    var product = 1;
 44+    for (var x = 0; x < flattenedValues.length; x++) {
 45+      product *= TypeCaster.valueToNumberGracefully(flattenedValues[x][i]);
 46+    }
 47+    result += product;
 48+  }
 49+  return result;
 50+};
 51+
 52+
 53 
 54 /**
 55  * Returns the Fisher transformation of a specified value.
 56diff --git a/src/RawFormulas/Utils.ts b/src/RawFormulas/Utils.ts
 57index 447d62a..a135858 100644
 58--- a/src/RawFormulas/Utils.ts
 59+++ b/src/RawFormulas/Utils.ts
 60@@ -116,6 +116,20 @@ class TypeCaster {
 61     }
 62     return 0;
 63   }
 64+
 65+  /**
 66+   * Converts any value to a number, defaulting to 0 value in cases in which it cannot coerce it to a number type
 67+   * @param value to conver
 68+   * @returns {number} to return. Will always return a number or 0.
 69+   */
 70+  static valueToNumberGracefully(value: any) : number {
 71+    try {
 72+      return TypeCaster.valueToNumber(value);
 73+    } catch (e) {
 74+      return 0;
 75+    }
 76+  }
 77+
 78   /**
 79    * Converts any value to a boolean or throws an error if it cannot coerce it to the boolean type.
 80    * @param value to convert
 81@@ -245,7 +259,7 @@ class Filter {
 82   }
 83 
 84   /**
 85-   * Flatten an array of arrays of ...
 86+   * Flatten an array of arrays of ...etc.
 87    * @param values array of values
 88    * @returns {Array} flattened array
 89    */
 90@@ -255,6 +269,20 @@ class Filter {
 91     }, []);
 92   }
 93 
 94+  /**
 95+   * Flatten an array of arrays of... etc, but throw an error if any are empty references.
 96+   * @param values array of values
 97+   * @returns {Array} flattened array
 98+   */
 99+  static flattenAndThrow(values: Array<any>) : Array<any> {
100+    return values.reduce(function (flat, toFlatten) {
101+      if (Array.isArray(toFlatten) && toFlatten.length === 0) {
102+        throw new CellError(ERRORS.REF_ERROR, "Reference does not exist.");
103+      }
104+      return flat.concat(Array.isArray(toFlatten) ? Filter.flatten(toFlatten) : toFlatten);
105+    }, []);
106+  }
107+
108   /**
109    * Filter out all strings from an array.
110    * @param arr to filter
111diff --git a/tests/FormulasTest.ts b/tests/FormulasTest.ts
112index 178a5b4..8a2341a 100644
113--- a/tests/FormulasTest.ts
114+++ b/tests/FormulasTest.ts
115@@ -1534,7 +1534,28 @@ catchAndAssertEquals(function() {
116 }, ERRORS.NA_ERROR);
117 
118 
119+// Test SUMPRODUCT
120+assertEquals(SUMPRODUCT([1, 5, 10], [2, 2, 2]), 32);
121+assertEquals(SUMPRODUCT([1, 5, 10], [2, 2, 2], [2, 2, 2]), 64);
122+assertEquals(SUMPRODUCT([1, 5, 10], [1, 2, 2], [1, 4, 4]), 121);
123 assertEquals(SUMPRODUCT([1, 5, 10]), 16);
124+assertEquals(SUMPRODUCT([1, 5, 10, ""]), 16);
125+assertEquals(SUMPRODUCT([1, 5, 10, 200], [2, 2, 2, ""]), 32);
126+assertEquals(SUMPRODUCT([1, 5, 10, "str"]), 16);
127+assertEquals(SUMPRODUCT([10, 10, 22, "str"], [2, 2, [2, 2]]), 84);
128+assertEquals(SUMPRODUCT(1, 5, 10), 50);
129+assertEquals(SUMPRODUCT([1, 5, 10]), 16);
130+catchAndAssertEquals(function() {
131+  SUMPRODUCT([1, 5, 10], [2, 2]);
132+}, ERRORS.VALUE_ERROR);
133+catchAndAssertEquals(function() {
134+  SUMPRODUCT([1, 5, 10], [2, 2, 2, []]);
135+}, ERRORS.REF_ERROR);
136+catchAndAssertEquals(function() {
137+  SUMPRODUCT();
138+}, ERRORS.NA_ERROR);
139+
140+
141 
142 // Test SUMSQ
143 assertEquals(SUMSQ([1, 5, 10], 10), 226);
144diff --git a/tests/SheetFormulaTest.ts b/tests/SheetFormulaTest.ts
145index 3a23768..b14cf85 100644
146--- a/tests/SheetFormulaTest.ts
147+++ b/tests/SheetFormulaTest.ts
148@@ -368,7 +368,7 @@ testFormula('=SUM(10, 10)', 20);
149 testFormula('=SUMIF([1, 5, 10], 5)', 5);
150 
151 // Test SUMPRODUCT
152-testFormula('=SUMPRODUCT([1, 5, 10])', 16);
153+testFormula('=SUMPRODUCT([1, 5, 10], [2, 2, 2])', 32);
154 
155 // Test SUMSQ
156 testFormula('=SUMSQ([1, 5, 10], 10)', 226);