diff --git a/modules/core/src/opencl/reduce.cl b/modules/core/src/opencl/reduce.cl
index e24c82a327..12e73b5b72 100644
--- a/modules/core/src/opencl/reduce.cl
+++ b/modules/core/src/opencl/reduce.cl
@@ -95,7 +95,11 @@
 #if cn != 3
 #define loadpix(addr) *(__global const srcT *)(addr)
 #define storepix(val, addr)  *(__global dstT *)(addr) = val
+#if kercn == 1
 #define srcTSIZE (int)sizeof(srcT)
+#else
+#define srcTSIZE (int)sizeof(srcT1)
+#endif
 #define dstTSIZE (int)sizeof(dstT)
 #else
 #define loadpix(addr) vload3(0, (__global const srcT1 *)(addr))
@@ -159,9 +163,53 @@
     dstT temp = convertToDT(loadpix(srcptr + src_index)), temp2 = convertToDT(loadpix(src2ptr + src2_index)); \
     FUNC(accumulator, temp, temp2)
 #else
+#if kercn == 1
 #define REDUCE_GLOBAL \
-    dstT temp = convertToDT(loadpix(srcptr + src_index)); \
+    dstTK temp = convertToDT(loadpix(srcptr + src_index)); \
     FUNC(accumulator, temp)
+#elif kercn == 2
+#define REDUCE_GLOBAL \
+    dstTK temp = convertToDT(loadpix(srcptr + src_index)); \
+    FUNC(accumulator, temp.s0); \
+    FUNC(accumulator, temp.s1)
+#elif kercn == 4
+#define REDUCE_GLOBAL \
+    dstTK temp = convertToDT(loadpix(srcptr + src_index)); \
+    FUNC(accumulator, temp.s0); \
+    FUNC(accumulator, temp.s1); \
+    FUNC(accumulator, temp.s2); \
+    FUNC(accumulator, temp.s3)
+#elif kercn == 8
+#define REDUCE_GLOBAL \
+    dstTK temp = convertToDT(loadpix(srcptr + src_index)); \
+    FUNC(accumulator, temp.s0); \
+    FUNC(accumulator, temp.s1); \
+    FUNC(accumulator, temp.s2); \
+    FUNC(accumulator, temp.s3); \
+    FUNC(accumulator, temp.s4); \
+    FUNC(accumulator, temp.s5); \
+    FUNC(accumulator, temp.s6); \
+    FUNC(accumulator, temp.s7)
+#elif kercn == 16
+#define REDUCE_GLOBAL \
+    dstTK temp = convertToDT(loadpix(srcptr + src_index)); \
+    FUNC(accumulator, temp.s0); \
+    FUNC(accumulator, temp.s1); \
+    FUNC(accumulator, temp.s2); \
+    FUNC(accumulator, temp.s3); \
+    FUNC(accumulator, temp.s4); \
+    FUNC(accumulator, temp.s5); \
+    FUNC(accumulator, temp.s6); \
+    FUNC(accumulator, temp.s7); \
+    FUNC(accumulator, temp.s8); \
+    FUNC(accumulator, temp.s9); \
+    FUNC(accumulator, temp.sA); \
+    FUNC(accumulator, temp.sB); \
+    FUNC(accumulator, temp.sC); \
+    FUNC(accumulator, temp.sD); \
+    FUNC(accumulator, temp.sE); \
+    FUNC(accumulator, temp.sF)
+#endif
 #endif
 
 #define SET_LOCAL_1 \
@@ -184,6 +232,11 @@
 #if kercn == 1
 #define REDUCE_GLOBAL \
     accumulator += loadpix(srcptr + src_index) == zero ? zero : one
+#elif kercn == 2
+#define REDUCE_GLOBAL \
+    srcT value = loadpix(srcptr + src_index); \
+    accumulator += value.s0 == zero ? zero : one; \
+    accumulator += value.s1 == zero ? zero : one
 #elif kercn == 4
 #define REDUCE_GLOBAL \
     srcT value = loadpix(srcptr + src_index); \
@@ -191,6 +244,17 @@
     accumulator += value.s1 == zero ? zero : one; \
     accumulator += value.s2 == zero ? zero : one; \
     accumulator += value.s3 == zero ? zero : one
+#elif kercn == 8
+#define REDUCE_GLOBAL \
+    srcT value = loadpix(srcptr + src_index); \
+    accumulator += value.s0 == zero ? zero : one; \
+    accumulator += value.s1 == zero ? zero : one; \
+    accumulator += value.s2 == zero ? zero : one; \
+    accumulator += value.s3 == zero ? zero : one; \
+    accumulator += value.s4 == zero ? zero : one; \
+    accumulator += value.s5 == zero ? zero : one; \
+    accumulator += value.s6 == zero ? zero : one; \
+    accumulator += value.s7 == zero ? zero : one
 #elif kercn == 16
 #define REDUCE_GLOBAL \
     srcT value = loadpix(srcptr + src_index); \
@@ -210,9 +274,8 @@
     accumulator += value.sD == zero ? zero : one; \
     accumulator += value.sE == zero ? zero : one; \
     accumulator += value.sF == zero ? zero : one
-#else
-#error "kercn should be either 1, 4 or 16"
 #endif
+
 #define SET_LOCAL_1 \
     localmem[lid] = accumulator
 #define REDUCE_LOCAL_1 \
diff --git a/modules/core/src/stat.cpp b/modules/core/src/stat.cpp
index e9fc538016..ae74acca26 100644
--- a/modules/core/src/stat.cpp
+++ b/modules/core/src/stat.cpp
@@ -473,8 +473,11 @@ static bool ocl_sum( InputArray _src, Scalar & res, int sum_op, InputArray _mask
 {
     CV_Assert(sum_op == OCL_OP_SUM || sum_op == OCL_OP_SUM_ABS || sum_op == OCL_OP_SUM_SQR);
 
-    int type = _src.type(), depth = CV_MAT_DEPTH(type), cn = CV_MAT_CN(type);
-    bool doubleSupport = ocl::Device::getDefault().doubleFPConfig() > 0;
+    bool doubleSupport = ocl::Device::getDefault().doubleFPConfig() > 0,
+            haveMask = _mask.kind() != _InputArray::NONE;
+    int type = _src.type(), depth = CV_MAT_DEPTH(type), cn = CV_MAT_CN(type),
+            kercn = cn == 1 && !haveMask ? ocl::predictOptimalVectorWidth(_src) : 1,
+            mcn = std::max(cn, kercn);
 
     if ( (!doubleSupport && depth == CV_64F) || cn > 4 )
         return false;
@@ -484,7 +487,6 @@ static bool ocl_sum( InputArray _src, Scalar & res, int sum_op, InputArray _mask
 
     int ddepth = std::max(sum_op == OCL_OP_SUM_SQR ? CV_32F : CV_32S, depth),
             dtype = CV_MAKE_TYPE(ddepth, cn);
-    bool haveMask = _mask.kind() != _InputArray::NONE;
     CV_Assert(!haveMask || _mask.type() == CV_8UC1);
 
     int wgs2_aligned = 1;
@@ -494,17 +496,19 @@ static bool ocl_sum( InputArray _src, Scalar & res, int sum_op, InputArray _mask
 
     static const char * const opMap[3] = { "OP_SUM", "OP_SUM_ABS", "OP_SUM_SQR" };
     char cvt[40];
-    ocl::Kernel k("reduce", ocl::core::reduce_oclsrc,
-                  format("-D srcT=%s -D srcT1=%s -D dstT=%s -D dstT1=%s -D ddepth=%d -D cn=%d"
-                         " -D convertToDT=%s -D %s -D WGS=%d -D WGS2_ALIGNED=%d%s%s%s%s",
-                         ocl::typeToStr(type), ocl::typeToStr(depth),
-                         ocl::typeToStr(dtype), ocl::typeToStr(ddepth), ddepth, cn,
-                         ocl::convertTypeStr(depth, ddepth, cn, cvt),
+    String opts = format("-D srcT=%s -D srcT1=%s -D dstT=%s -D dstTK=%s -D dstT1=%s -D ddepth=%d -D cn=%d"
+                         " -D convertToDT=%s -D %s -D WGS=%d -D WGS2_ALIGNED=%d%s%s%s%s -D kercn=%d",
+                         ocl::typeToStr(CV_MAKE_TYPE(depth, mcn)), ocl::typeToStr(depth),
+                         ocl::typeToStr(dtype), ocl::typeToStr(CV_MAKE_TYPE(ddepth, mcn)),
+                         ocl::typeToStr(ddepth), ddepth, cn,
+                         ocl::convertTypeStr(depth, ddepth, mcn, cvt),
                          opMap[sum_op], (int)wgs, wgs2_aligned,
                          doubleSupport ? " -D DOUBLE_SUPPORT" : "",
                          haveMask ? " -D HAVE_MASK" : "",
                          _src.isContinuous() ? " -D HAVE_SRC_CONT" : "",
-                         _mask.isContinuous() ? " -D HAVE_MASK_CONT" : ""));
+                         _mask.isContinuous() ? " -D HAVE_MASK_CONT" : "", kercn);
+
+    ocl::Kernel k("reduce", ocl::core::reduce_oclsrc, opts);
     if (k.empty())
         return false;
 
@@ -660,8 +664,8 @@ static bool ocl_countNonZero( InputArray _src, int & res )
     wgs2_aligned >>= 1;
 
     ocl::Kernel k("reduce", ocl::core::reduce_oclsrc,
-                  format("-D srcT=%s -D srcT1=%s -D cn=1 -D OP_COUNT_NON_ZERO -D WGS=%d "
-                         "-D kercn=%d -D WGS2_ALIGNED=%d%s%s",
+                  format("-D srcT=%s -D srcT1=%s -D cn=1 -D OP_COUNT_NON_ZERO"
+                         " -D WGS=%d -D kercn=%d -D WGS2_ALIGNED=%d%s%s",
                          ocl::typeToStr(CV_MAKE_TYPE(depth, kercn)),
                          ocl::typeToStr(depth), (int)wgs, kercn,
                          wgs2_aligned, doubleSupport ? " -D DOUBLE_SUPPORT" : "",
@@ -1292,7 +1296,7 @@ static bool ocl_minMaxIdx( InputArray _src, double* minVal, double* maxVal, int*
     CV_Assert( (_src.channels() == 1 && (_mask.empty() || _mask.type() == CV_8U)) ||
         (_src.channels() >= 1 && _mask.empty() && !minLoc && !maxLoc) );
 
-    int type = _src.type(), depth = CV_MAT_DEPTH(type);
+    int type = _src.type(), depth = CV_MAT_DEPTH(type), kercn = 1;
     bool doubleSupport = ocl::Device::getDefault().doubleFPConfig() > 0;
 
     if (depth == CV_64F && !doubleSupport)
@@ -1306,11 +1310,12 @@ static bool ocl_minMaxIdx( InputArray _src, double* minVal, double* maxVal, int*
         wgs2_aligned <<= 1;
     wgs2_aligned >>= 1;
 
-    String opts = format("-D DEPTH_%d -D srcT=%s -D OP_MIN_MAX_LOC%s -D WGS=%d -D WGS2_ALIGNED=%d%s%s%s",
+    String opts = format("-D DEPTH_%d -D srcT=%s -D OP_MIN_MAX_LOC%s -D WGS=%d"
+                         " -D WGS2_ALIGNED=%d%s%s%s -D kercn=%d",
                          depth, ocl::typeToStr(depth), _mask.empty() ? "" : "_MASK", (int)wgs,
                          wgs2_aligned, doubleSupport ? " -D DOUBLE_SUPPORT" : "",
                          _src.isContinuous() ? " -D HAVE_SRC_CONT" : "",
-                         _mask.isContinuous() ? " -D HAVE_MASK_CONT" : "");
+                         _mask.isContinuous() ? " -D HAVE_MASK_CONT" : "", kercn);
 
     ocl::Kernel k("reduce", ocl::core::reduce_oclsrc, opts);
     if (k.empty())
diff --git a/modules/core/src/umatrix.cpp b/modules/core/src/umatrix.cpp
index 07dd07fbe2..11148bcded 100644
--- a/modules/core/src/umatrix.cpp
+++ b/modules/core/src/umatrix.cpp
@@ -836,7 +836,7 @@ UMat UMat::mul(InputArray m, double scale) const
 
 static bool ocl_dot( InputArray _src1, InputArray _src2, double & res )
 {
-    int type = _src1.type(), depth = CV_MAT_DEPTH(type);
+    int type = _src1.type(), depth = CV_MAT_DEPTH(type), kercn = 1;
     bool doubleSupport = ocl::Device::getDefault().doubleFPConfig() > 0;
 
     if ( !doubleSupport && depth == CV_64F )
@@ -853,11 +853,13 @@ static bool ocl_dot( InputArray _src1, InputArray _src2, double & res )
 
     char cvt[40];
     ocl::Kernel k("reduce", ocl::core::reduce_oclsrc,
-                  format("-D srcT=%s -D dstT=%s -D ddepth=%d -D convertToDT=%s -D OP_DOT -D WGS=%d -D WGS2_ALIGNED=%d%s%s%s",
-                         ocl::typeToStr(depth), ocl::typeToStr(ddepth), ddepth, ocl::convertTypeStr(depth, ddepth, 1, cvt),
+                  format("-D srcT=%s -D dstT=%s -D ddepth=%d -D convertToDT=%s -D OP_DOT "
+                         "-D WGS=%d -D WGS2_ALIGNED=%d%s%s%s -D kercn=%d",
+                         ocl::typeToStr(depth), ocl::typeToStr(ddepth), ddepth,
+                         ocl::convertTypeStr(depth, ddepth, 1, cvt),
                          (int)wgs, wgs2_aligned, doubleSupport ? " -D DOUBLE_SUPPORT" : "",
                          _src1.isContinuous() ? " -D HAVE_SRC_CONT" : "",
-                         _src2.isContinuous() ? " -D HAVE_SRC2_CONT" : ""));
+                         _src2.isContinuous() ? " -D HAVE_SRC2_CONT" : "", kercn));
     if (k.empty())
         return false;