diff --git a/ClosedXML/Excel/Cells/XLCell.cs b/ClosedXML/Excel/Cells/XLCell.cs
index 2a163a9..ac179bb 100644
--- a/ClosedXML/Excel/Cells/XLCell.cs
+++ b/ClosedXML/Excel/Cells/XLCell.cs
@@ -241,7 +241,7 @@
                 var dtTest = (DateTime)Convert.ChangeType(value, typeof (DateTime));
                 Style.NumberFormat.NumberFormatId = dtTest.Date == dtTest ? 14 : 22;
 
-                _cellValue = dtTest.ToOADate().ToString();
+                _cellValue = dtTest.ToOADate().ToString(XLHelper.ParseCulture);
             }
             else if (
                 value is sbyte
@@ -266,7 +266,7 @@
                 else
                 {
                     _dataType = XLCellValues.Number;
-                    _cellValue = value.ToString();
+                    _cellValue = ((Double)Convert.ChangeType(value, typeof (Double))).ToString(XLHelper.ParseCulture);
                 }
             }
             else if (value is Boolean)
@@ -343,7 +343,7 @@
             if (_dataType == XLCellValues.DateTime || IsDateFormat())
             {
                 double dTest;
-                if (Double.TryParse(cValue, out dTest))
+                if (Double.TryParse(cValue, XLHelper.NumberStyle, XLHelper.ParseCulture, out dTest))
                 {
                     var format = GetFormat();
                     return DateTime.FromOADate(dTest).ToString(format);
@@ -355,7 +355,7 @@
             if (_dataType == XLCellValues.Number)
             {
                 double dTest;
-                if (Double.TryParse(cValue, out dTest))
+                if (Double.TryParse(cValue, XLHelper.NumberStyle, XLHelper.ParseCulture, out dTest))
                 {
                     var format = GetFormat();
                     return dTest.ToString(format);
@@ -418,10 +418,10 @@
                     return cellValue != "0";
 
                 if (_dataType == XLCellValues.DateTime)
-                    return DateTime.FromOADate(Double.Parse(cellValue));
+                    return DateTime.FromOADate(Double.Parse(cellValue, XLHelper.NumberStyle, XLHelper.ParseCulture));
 
                 if (_dataType == XLCellValues.Number)
-                    return Double.Parse(cellValue);
+                    return Double.Parse(cellValue, XLHelper.NumberStyle, XLHelper.ParseCulture);
 
                 if (_dataType == XLCellValues.TimeSpan)
                 {
@@ -813,9 +813,9 @@
                         DateTime dtTest;
                         double dblTest;
                         if (DateTime.TryParse(_cellValue, out dtTest))
-                            _cellValue = dtTest.ToOADate().ToString();
-                        else if (Double.TryParse(_cellValue, out dblTest))
-                            _cellValue = dblTest.ToString();
+                            _cellValue = dtTest.ToOADate().ToString(XLHelper.ParseCulture);
+                        else if (Double.TryParse(_cellValue, XLHelper.NumberStyle, XLHelper.ParseCulture, out dblTest))
+                            _cellValue = dblTest.ToString(XLHelper.ParseCulture);
                         else
                         {
                             throw new ArgumentException(
@@ -841,7 +841,7 @@
                         {
                             try
                             {
-                                _cellValue = (DateTime.FromOADate(Double.Parse(_cellValue)) - BaseDate).ToString();
+                                _cellValue = (DateTime.FromOADate(Double.Parse(_cellValue, XLHelper.NumberStyle, XLHelper.ParseCulture)) - BaseDate).ToString();
                             }
                             catch
                             {
@@ -855,8 +855,8 @@
                     else if (value == XLCellValues.Number)
                     {
                         double dTest;
-                        if (Double.TryParse(_cellValue, out dTest))
-                            _cellValue = Double.Parse(_cellValue).ToString();
+                        if (Double.TryParse(_cellValue, NumberStyles.AllowDecimalPoint, CultureInfo.InvariantCulture, out dTest))
+                            _cellValue = dTest.ToString(CultureInfo.InvariantCulture);
                         else
                         {
                             throw new ArgumentException(
@@ -1620,6 +1620,8 @@
                 val = string.Empty;
             else if (value is DateTime)
                 val = ((DateTime)value).ToString("o");
+            else if (value is double)
+                val = ((double)value).ToString(XLHelper.ParseCulture);
             else
                 val = value.ToString();
             _richText = null;
@@ -1645,7 +1647,7 @@
                     if (val.Contains(Environment.NewLine) && !style.Alignment.WrapText)
                         Style.Alignment.WrapText = true;
                 }
-                else if (value is TimeSpan || (!Double.TryParse(val, out dTest) && TimeSpan.TryParse(val, out tsTest)))
+                else if (value is TimeSpan || (!Double.TryParse(val, XLHelper.NumberStyle, XLHelper.ParseCulture, out dTest) && TimeSpan.TryParse(val, out tsTest)))
                 {
                     if (!(value is TimeSpan) && TimeSpan.TryParse(val, out tsTest))
                         val = tsTest.ToString();
@@ -1654,7 +1656,7 @@
                     if (style.NumberFormat.Format == String.Empty && style.NumberFormat.NumberFormatId == 0)
                         Style.NumberFormat.NumberFormatId = 46;
                 }
-                else if (val.Trim() != "NaN" &&  Double.TryParse(val, out dTest))
+                else if (val.Trim() != "NaN" &&  Double.TryParse(val, XLHelper.NumberStyle, XLHelper.ParseCulture, out dTest))
                     _dataType = XLCellValues.Number;
                 else if (DateTime.TryParse(val, out dtTest) && dtTest >= BaseDate)
                 {
@@ -1667,11 +1669,11 @@
                         DateTime forMillis;
                         if (value is DateTime && (forMillis = (DateTime)value).Millisecond > 0)
                         {
-                            val = forMillis.ToOADate().ToString();
+                            val = forMillis.ToOADate().ToString(XLHelper.ParseCulture);
                         }
                         else
                         {
-                            val = dtTest.ToOADate().ToString();
+                            val = dtTest.ToOADate().ToString(XLHelper.ParseCulture);
                         }
                     }
                     
diff --git a/ClosedXML/Excel/Ranges/XLRangeRow.cs b/ClosedXML/Excel/Ranges/XLRangeRow.cs
index 802342f..df4e9da 100644
--- a/ClosedXML/Excel/Ranges/XLRangeRow.cs
+++ b/ClosedXML/Excel/Ranges/XLRangeRow.cs
@@ -256,7 +256,7 @@
                         else if (thisCell.DataType == XLCellValues.TimeSpan)
                             comparison = thisCell.GetTimeSpan().CompareTo(otherCell.GetTimeSpan());
                         else
-                            comparison = Double.Parse(thisCell.InnerText).CompareTo(Double.Parse(otherCell.InnerText));
+                            comparison = Double.Parse(thisCell.InnerText, XLHelper.NumberStyle, XLHelper.ParseCulture).CompareTo(Double.Parse(otherCell.InnerText, XLHelper.NumberStyle, XLHelper.ParseCulture));
                     }
                     else if (e.MatchCase)
                         comparison = String.Compare(thisCell.GetString(), otherCell.GetString(), true);
diff --git a/ClosedXML/Excel/XLWorkbook_Load.cs b/ClosedXML/Excel/XLWorkbook_Load.cs
index bed27ac..58fa9ba 100644
--- a/ClosedXML/Excel/XLWorkbook_Load.cs
+++ b/ClosedXML/Excel/XLWorkbook_Load.cs
@@ -890,7 +890,7 @@
                     {
                         if (!XLHelper.IsNullOrWhiteSpace(cell.CellValue.Text))
                         {
-                            var sharedString = sharedStrings[Int32.Parse(cell.CellValue.Text)];
+                            var sharedString = sharedStrings[Int32.Parse(cell.CellValue.Text, XLHelper.NumberStyle, XLHelper.ParseCulture)];
 
                             var runs = sharedString.Elements<Run>();
                             var phoneticRuns = sharedString.Elements<PhoneticRun>();
@@ -950,7 +950,7 @@
                 else if (cell.DataType == CellValues.Date)
                 {
                     if (!XLHelper.IsNullOrWhiteSpace(cell.CellValue.Text))
-                        xlCell._cellValue = Double.Parse(cell.CellValue.Text, CultureInfo.InvariantCulture).ToString();
+                        xlCell._cellValue = Double.Parse(cell.CellValue.Text, CultureInfo.InvariantCulture).ToString(XLHelper.ParseCulture);
                     xlCell._dataType = XLCellValues.DateTime;
                 }
                 else if (cell.DataType == CellValues.Boolean)
@@ -961,7 +961,7 @@
                 else if (cell.DataType == CellValues.Number)
                 {
                     if (!XLHelper.IsNullOrWhiteSpace(cell.CellValue.Text))
-                        xlCell._cellValue = Double.Parse(cell.CellValue.Text, CultureInfo.InvariantCulture).ToString();
+                        xlCell._cellValue = Double.Parse(cell.CellValue.Text, CultureInfo.InvariantCulture).ToString(XLHelper.ParseCulture);
                     if (s == null)
                     {
                         xlCell._dataType = XLCellValues.Number;
@@ -987,7 +987,7 @@
                 {
                     var numberFormatId = ((CellFormat) (s.CellFormats).ElementAt(styleIndex)).NumberFormatId;
                     if (!XLHelper.IsNullOrWhiteSpace(cell.CellValue.Text))
-                        xlCell._cellValue = Double.Parse(cell.CellValue.Text, CultureInfo.InvariantCulture).ToString();
+                        xlCell._cellValue = Double.Parse(cell.CellValue.Text, CultureInfo.InvariantCulture).ToString(XLHelper.ParseCulture);
                     if (s.NumberingFormats != null &&
                         s.NumberingFormats.Any(nf => ((NumberingFormat) nf).NumberFormatId.Value == numberFormatId))
                     {
diff --git a/ClosedXML/Excel/XLWorkbook_Save.cs b/ClosedXML/Excel/XLWorkbook_Save.cs
index 0ad3737..c6084d6 100644
--- a/ClosedXML/Excel/XLWorkbook_Save.cs
+++ b/ClosedXML/Excel/XLWorkbook_Save.cs
@@ -3916,7 +3916,7 @@
                                 if (!XLHelper.IsNullOrWhiteSpace(opCell.InnerText))
                                 {
                                     var cellValue = new CellValue();
-                                    cellValue.Text = Double.Parse(opCell.InnerText).ToString(CultureInfo.InvariantCulture);
+                                    cellValue.Text = Double.Parse(opCell.InnerText, NumberStyles.AllowDecimalPoint, CultureInfo.InvariantCulture).ToString(CultureInfo.InvariantCulture);
                                     cell.CellValue = cellValue;
                                 }
                             }
diff --git a/ClosedXML/XLHelper.cs b/ClosedXML/XLHelper.cs
index d5f704d..a5983ec 100644
--- a/ClosedXML/XLHelper.cs
+++ b/ClosedXML/XLHelper.cs
@@ -25,6 +25,8 @@
         internal static readonly NumberFormatInfo NumberFormatForParse = CultureInfo.InvariantCulture.NumberFormat;
         internal static readonly Graphics Graphic = Graphics.FromImage(new Bitmap(200, 200));
         internal static readonly Double DpiX = Graphic.DpiX;
+        internal static readonly NumberStyles NumberStyle = NumberStyles.AllowDecimalPoint;
+        internal static readonly CultureInfo ParseCulture = CultureInfo.InvariantCulture;
 
         internal static readonly Regex A1SimpleRegex = new Regex(
             @"\A"