diff --git a/storm/Big.cpp b/storm/Big.cpp
index 141f3fc..93f8017 100644
--- a/storm/Big.cpp
+++ b/storm/Big.cpp
@@ -81,6 +81,10 @@ int32_t SBigIsOne(BigData* a) {
     return IsOne(a->Primary());
 }
 
+int32_t SBigIsZero(BigData* a) {
+    return IsZero(a->Primary());
+}
+
 void SBigMod(BigData* a, BigData* b, BigData* c) {
     uint32_t allocCount = 0;
     auto& scratch = a->Stack().Alloc(&allocCount);
diff --git a/storm/Big.hpp b/storm/Big.hpp
index f7968e6..36e783d 100644
--- a/storm/Big.hpp
+++ b/storm/Big.hpp
@@ -34,6 +34,8 @@ int32_t SBigIsOdd(BigData* a);
 
 int32_t SBigIsOne(BigData* a);
 
+int32_t SBigIsZero(BigData* a);
+
 void SBigMod(BigData* a, BigData* b, BigData* c);
 
 void SBigMul(BigData* a, BigData* b, BigData* c);
diff --git a/storm/big/Ops.cpp b/storm/big/Ops.cpp
index c96064c..5b30274 100644
--- a/storm/big/Ops.cpp
+++ b/storm/big/Ops.cpp
@@ -225,6 +225,11 @@ int32_t IsOne(const BigBuffer &num) {
     return num.Count() == 1 && num[0] == 1;
 }
 
+int32_t IsZero(const BigBuffer &num) {
+    num.Trim();
+    return num.Count() == 0;
+}
+
 uint64_t MakeLarge(uint32_t low, uint32_t high) {
     return low + (static_cast<uint64_t>(high) << 32);
 }
diff --git a/storm/big/Ops.hpp b/storm/big/Ops.hpp
index 84e54cb..5dd3b8d 100644
--- a/storm/big/Ops.hpp
+++ b/storm/big/Ops.hpp
@@ -39,6 +39,8 @@ int32_t IsOdd(const BigBuffer &num);
 
 int32_t IsOne(const BigBuffer &num);
 
+int32_t IsZero(const BigBuffer &num);
+
 uint64_t MakeLarge(uint32_t low, uint32_t high);
 
 void Mul(BigBuffer& a, const BigBuffer& b, uint64_t c);
diff --git a/test/Big.cpp b/test/Big.cpp
index 36ccac9..3620523 100644
--- a/test/Big.cpp
+++ b/test/Big.cpp
@@ -486,6 +486,26 @@ TEST_CASE("SBigIsOne", "[big]") {
     }
 }
 
+TEST_CASE("SBigIsZero", "[big]") {
+    BigDataTest a;
+
+    SECTION("unset is zero") {
+        CHECK(SBigIsZero(a));
+    }
+
+    SECTION("0 is 0") {
+        SBigFromUnsigned(a, 0);
+        CHECK(SBigIsZero(a));
+    }
+
+    SECTION("numbers are not 0") {
+        auto v = GENERATE(1ULL, 2ULL, 10ULL, 0xFFFFFFFFULL, 10000000000000ULL, 0xFF00000000000000ULL);
+
+        SBigFromStr(a, std::to_string(v).c_str());
+        CHECK_FALSE(SBigIsZero(a));
+    }
+}
+
 TEST_CASE("SBigMod", "[big]") {
     SECTION("mods 7 by 4") {
         BigData* a;