diff --git a/NDSFactory.pro b/NDSFactory.pro
index f4196f6..c0c4f89 100644
--- a/NDSFactory.pro
+++ b/NDSFactory.pro
@@ -41,7 +41,8 @@ HEADERS += \
     ndsheader.h \
     ndsfactory.h \
     aboutdialog.h \
-    fatstruct.h
+    fatstruct.h \
+    crctable.h
 
 FORMS += \
         mainwindow.ui \
diff --git a/crctable.h b/crctable.h
new file mode 100644
index 0000000..8c8c29a
--- /dev/null
+++ b/crctable.h
@@ -0,0 +1,43 @@
+#ifndef CRCTABLE_H
+#define CRCTABLE_H
+
+#include <cstdint>
+
+
+static const uint16_t lCRCTable[] =
+{
+    0x0000, 0xC0C1, 0xC181, 0x0140, 0xC301, 0x03C0, 0x0280, 0xC241,
+    0xC601, 0x06C0, 0x0780, 0xC741, 0x0500, 0xC5C1, 0xC481, 0x0440,
+    0xCC01, 0x0CC0, 0x0D80, 0xCD41, 0x0F00, 0xCFC1, 0xCE81, 0x0E40,
+    0x0A00, 0xCAC1, 0xCB81, 0x0B40, 0xC901, 0x09C0, 0x0880, 0xC841,
+    0xD801, 0x18C0, 0x1980, 0xD941, 0x1B00, 0xDBC1, 0xDA81, 0x1A40,
+    0x1E00, 0xDEC1, 0xDF81, 0x1F40, 0xDD01, 0x1DC0, 0x1C80, 0xDC41,
+    0x1400, 0xD4C1, 0xD581, 0x1540, 0xD701, 0x17C0, 0x1680, 0xD641,
+    0xD201, 0x12C0, 0x1380, 0xD341, 0x1100, 0xD1C1, 0xD081, 0x1040,
+    0xF001, 0x30C0, 0x3180, 0xF141, 0x3300, 0xF3C1, 0xF281, 0x3240,
+    0x3600, 0xF6C1, 0xF781, 0x3740, 0xF501, 0x35C0, 0x3480, 0xF441,
+    0x3C00, 0xFCC1, 0xFD81, 0x3D40, 0xFF01, 0x3FC0, 0x3E80, 0xFE41,
+    0xFA01, 0x3AC0, 0x3B80, 0xFB41, 0x3900, 0xF9C1, 0xF881, 0x3840,
+    0x2800, 0xE8C1, 0xE981, 0x2940, 0xEB01, 0x2BC0, 0x2A80, 0xEA41,
+    0xEE01, 0x2EC0, 0x2F80, 0xEF41, 0x2D00, 0xEDC1, 0xEC81, 0x2C40,
+    0xE401, 0x24C0, 0x2580, 0xE541, 0x2700, 0xE7C1, 0xE681, 0x2640,
+    0x2200, 0xE2C1, 0xE381, 0x2340, 0xE101, 0x21C0, 0x2080, 0xE041,
+    0xA001, 0x60C0, 0x6180, 0xA141, 0x6300, 0xA3C1, 0xA281, 0x6240,
+    0x6600, 0xA6C1, 0xA781, 0x6740, 0xA501, 0x65C0, 0x6480, 0xA441,
+    0x6C00, 0xACC1, 0xAD81, 0x6D40, 0xAF01, 0x6FC0, 0x6E80, 0xAE41,
+    0xAA01, 0x6AC0, 0x6B80, 0xAB41, 0x6900, 0xA9C1, 0xA881, 0x6840,
+    0x7800, 0xB8C1, 0xB981, 0x7940, 0xBB01, 0x7BC0, 0x7A80, 0xBA41,
+    0xBE01, 0x7EC0, 0x7F80, 0xBF41, 0x7D00, 0xBDC1, 0xBC81, 0x7C40,
+    0xB401, 0x74C0, 0x7580, 0xB541, 0x7700, 0xB7C1, 0xB681, 0x7640,
+    0x7200, 0xB2C1, 0xB381, 0x7340, 0xB101, 0x71C0, 0x7080, 0xB041,
+    0x5000, 0x90C1, 0x9181, 0x5140, 0x9301, 0x53C0, 0x5280, 0x9241,
+    0x9601, 0x56C0, 0x5780, 0x9741, 0x5500, 0x95C1, 0x9481, 0x5440,
+    0x9C01, 0x5CC0, 0x5D80, 0x9D41, 0x5F00, 0x9FC1, 0x9E81, 0x5E40,
+    0x5A00, 0x9AC1, 0x9B81, 0x5B40, 0x9901, 0x59C0, 0x5880, 0x9841,
+    0x8801, 0x48C0, 0x4980, 0x8941, 0x4B00, 0x8BC1, 0x8A81, 0x4A40,
+    0x4E00, 0x8EC1, 0x8F81, 0x4F40, 0x8D01, 0x4DC0, 0x4C80, 0x8C41,
+    0x4400, 0x84C1, 0x8581, 0x4540, 0x8701, 0x47C0, 0x4680, 0x8641,
+    0x8201, 0x42C0, 0x4380, 0x8341, 0x4100, 0x81C1, 0x8081, 0x4040
+};
+
+#endif // CRCTABLE_H
diff --git a/mainwindow.h b/mainwindow.h
index 233b8b5..b075a68 100644
--- a/mainwindow.h
+++ b/mainwindow.h
@@ -54,6 +54,8 @@ private slots:
 
     void on_fatPatchingPatchFatBtn_clicked();
 
+    void on_packerCalcHeaderCrcBtn_clicked();
+
 private:
     Ui::MainWindow *ui;
     NDSFactory ndsFactory;
@@ -74,7 +76,9 @@ private:
     bool dumpEverything(QString dirPath);
 
     void populatePackerSectionHeader(NDSHeader *ndsHeader);
+    void generateHeader(NDSHeader* pRomHeader);
     bool writeHeader(const std::string& savePath);
+    void calcHeaderCrc16();
     bool writeArm9Bin(const std::string& savePath, bool isArm9FooterPresent);
     bool writeArm7Bin(const std::string& savePath);
     bool writeFnt(const std::string& savePath);
diff --git a/mainwindow.ui b/mainwindow.ui
index e8ff17a..999aba0 100644
--- a/mainwindow.ui
+++ b/mainwindow.ui
@@ -1626,6 +1626,13 @@
                </property>
               </spacer>
              </item>
+             <item>
+              <widget class="QPushButton" name="packerCalcHeaderCrcBtn">
+               <property name="text">
+                <string>Calc Header CRC</string>
+               </property>
+              </widget>
+             </item>
              <item>
               <widget class="QPushButton" name="packerLoadHeaderBtn">
                <property name="sizePolicy">
diff --git a/ndsfactory.cpp b/ndsfactory.cpp
index 6d95f3f..0647f40 100644
--- a/ndsfactory.cpp
+++ b/ndsfactory.cpp
@@ -4,6 +4,7 @@
 #include <cmath>
 #include "ndsfactory.h"
 #include "fatstruct.h"
+#include "crctable.h"
 
 
 NDSFactory::NDSFactory()
@@ -145,3 +146,21 @@ bool NDSFactory::patchFat(const std::string& fatSectionPath, uint32_t shiftSize,
 
     return writeBytesToFile(fatBytes, savePath, 0, static_cast<uint32_t>(sectionSize));
 }
+
+uint16_t NDSFactory::calcHeaderCrc16(const std::vector<char>& romHeader)
+{
+    uint8_t loc;
+    uint16_t crc = 0xFFFF;
+    size_t size = 0x15E;
+    size_t index = 0;
+
+   while (size--)
+   {
+       loc = static_cast<unsigned char>(romHeader[index] ^ crc);
+       index++;
+       crc >>= 8;
+       crc ^= lCRCTable[loc];
+   }
+   return crc;
+
+}
diff --git a/ndsfactory.h b/ndsfactory.h
index ad8f8b1..cad54eb 100644
--- a/ndsfactory.h
+++ b/ndsfactory.h
@@ -21,6 +21,7 @@ public:
     int getCardSizeInBytes(int cardType);
     bool checkArm9FooterPresence(const std::string& sectionPath, uint32_t size);
     bool patchFat(const std::string& sectionPath, uint32_t shiftSize, const std::string& savePath);
+    uint16_t calcHeaderCrc16(const std::vector<char>& romHeader);
 
 private:
 
diff --git a/packertabfunctions.cpp b/packertabfunctions.cpp
index 9b7c00e..dce5c75 100644
--- a/packertabfunctions.cpp
+++ b/packertabfunctions.cpp
@@ -58,12 +58,8 @@ void MainWindow::populatePackerSectionHeader(NDSHeader *ndsHeader)
     ui->packerDebugRamAddrEdt->setText(QString::number(ndsHeader->DebugRamAddr, 16));
 }
 
-
-bool MainWindow::writeHeader(const std::string& savePath)
+void MainWindow::generateHeader(NDSHeader* pRomHeader)
 {
-    std::vector<char> romHeader(sizeof(NDSHeader));
-    NDSHeader* pRomHeader = reinterpret_cast<NDSHeader*>(romHeader.data());
-
     std::copy_n(ui->packerGameTitleEdt->text().toLatin1().data(), 0xc, std::begin(pRomHeader->GameTitle));
     std::copy_n(ui->packerGameCodeEdt->text().toStdString().data(), 0x4, std::begin(pRomHeader->GameCode));
     std::copy_n(ui->packerMakerCodeEdt->text().toStdString().data(), 0x2, std::begin(pRomHeader->MakerCode));
@@ -121,10 +117,30 @@ bool MainWindow::writeHeader(const std::string& savePath)
 
     std::fill(std::begin(pRomHeader->Reserved3), std::end(pRomHeader->Reserved3), 0);
     std::fill(std::begin(pRomHeader->Reserved4), std::end(pRomHeader->Reserved4), 0);
+}
+
+
+bool MainWindow::writeHeader(const std::string& savePath)
+{
+    std::vector<char> romHeader(sizeof(NDSHeader));
+    NDSHeader* pRomHeader = reinterpret_cast<NDSHeader*>(romHeader.data());
+
+    generateHeader(pRomHeader);
 
     return ndsFactory.writeBytesToFile(romHeader, savePath, 0, sizeof(NDSHeader));;
 }
 
+void MainWindow::calcHeaderCrc16()
+{
+    std::vector<char> romHeader(sizeof(NDSHeader));
+    NDSHeader* pRomHeader = reinterpret_cast<NDSHeader*>(romHeader.data());
+
+    generateHeader(pRomHeader);
+
+    ui->packerHeaderCRCEdt->setText(QString::number(ndsFactory.calcHeaderCrc16(romHeader), 16));
+
+}
+
 bool MainWindow::writeArm9Bin(const std::string& savePath, bool isArm9FooterPresent)
 {
     uint32_t size =  ui->packerARM9SizeEdt->text().toUInt(nullptr, 16);
@@ -309,7 +325,6 @@ bool MainWindow::writeRomPadding(const std::string& savePath)
                  size);
 }
 
-
 bool MainWindow::writeEverything(const std::string& savePath)
 {
     bool res = true;
diff --git a/packertabsignals.cpp b/packertabsignals.cpp
index 1cfae90..7a4d3e6 100644
--- a/packertabsignals.cpp
+++ b/packertabsignals.cpp
@@ -183,3 +183,8 @@ void MainWindow::on_packerBuildNDSRomBtn_clicked()
     }
 }
 
+
+void MainWindow::on_packerCalcHeaderCrcBtn_clicked()
+{
+    calcHeaderCrc16();
+}