1diff --git a/src/Formulas/Math.ts b/src/Formulas/Math.ts
 2index 80a582f..dd69b4e 100644
 3--- a/src/Formulas/Math.ts
 4+++ b/src/Formulas/Math.ts
 5@@ -714,7 +714,6 @@ var ROUNDUP = function (...values) {
 6  * @param values[2] (optional) The range to be summed, if different from range.
 7  * @returns {number}
 8  * @constructor
 9- * TODO: This needs to take nested range values.
10  */
11 var SUMIF = function (...values) {
12   ArgsChecker.checkLengthWithin(values, 2, 3);
13@@ -730,13 +729,17 @@ var SUMIF = function (...values) {
14   var sum = 0;
15   for (var i = 0; i < range.length; i++) {
16     var x = range[i];
17-    if (sumRange && i > sumRange.length-1) {
18-      continue;
19-    }
20-    if (values.length === 2 && TypeCaster.canCoerceToNumber(x) && criteriaEvaluation(x)) {
21-      sum = sum + TypeCaster.valueToNumber(x);
22-    } else if (values.length === 3 && TypeCaster.canCoerceToNumber(sumRange[i]) && criteriaEvaluation(x)) {
23-      sum = sum + TypeCaster.valueToNumber(sumRange[i]);
24+    if (x instanceof Array) {
25+      sum += SUMIF.apply(this, [x, criteria]);
26+    } else {
27+      if (sumRange && i > sumRange.length-1) {
28+        continue;
29+      }
30+      if (values.length === 2 && TypeCaster.canCoerceToNumber(x) && criteriaEvaluation(x)) {
31+        sum = sum + TypeCaster.valueToNumber(x);
32+      } else if (values.length === 3 && TypeCaster.canCoerceToNumber(sumRange[i]) && criteriaEvaluation(x)) {
33+        sum = sum + TypeCaster.valueToNumber(sumRange[i]);
34+      }
35     }
36   }
37   return sum;
38diff --git a/tests/Formulas/MathTest.ts b/tests/Formulas/MathTest.ts
39index 6ae5f6b..4606a89 100644
40--- a/tests/Formulas/MathTest.ts
41+++ b/tests/Formulas/MathTest.ts
42@@ -935,6 +935,9 @@ test("SUM", function(){
43 
44 
45 test("SUMIF", function(){
46+  assertEquals(SUMIF([1, 5, 10, [1, 1, 1, 1, 1], []], 1), 6);
47+  assertEquals(SUMIF([], 1), 0);
48+  assertEquals(SUMIF([1, 5, 10, [1, 1, "1.0", "1", 1]], 1), 4);
49   assertEquals(SUMIF([1, 5, 10], 5), 5);
50   assertEquals(SUMIF([1, 5, 5, 5, 10, 5], 5), 20);
51   assertEquals(SUMIF([1, 5, 5, 5, 10, 5], 10), 10);