diff --git a/renderdoc/driver/gl/gl_replay.cpp b/renderdoc/driver/gl/gl_replay.cpp
index 264b739bc..890595119 100644
--- a/renderdoc/driver/gl/gl_replay.cpp
+++ b/renderdoc/driver/gl/gl_replay.cpp
@@ -457,8 +457,30 @@ FetchTexture GLReplay::GetTexture(ResourceId id)
 	if(res.resource.name == gl.m_FakeBB_Color || res.resource.name == gl.m_FakeBB_DepthStencil)
 		tex.creationFlags |= eTextureCreate_SwapBuffer;
 
+	GLint compressed;
+	gl.glGetTexLevelParameteriv(levelQueryType, 0, eGL_TEXTURE_COMPRESSED, &compressed);
 	tex.byteSize = 0;
-	GLNOTIMP("Not calculating bytesize");
+	for(uint32_t a=0; a < tex.arraysize; a++)
+	{
+		for(uint32_t m=0; m < tex.mips; m++)
+		{
+			if(compressed)
+			{
+				gl.glGetTexLevelParameteriv(levelQueryType, m, eGL_TEXTURE_COMPRESSED_IMAGE_SIZE, &compressed);
+				tex.byteSize += compressed;
+			}
+			else if(tex.format.special)
+			{
+				tex.byteSize += GetByteSize(RDCMAX(1U, tex.width>>m), RDCMAX(1U, tex.height>>m), RDCMAX(1U, tex.depth>>m), 
+																		(GLenum)fmt, (GLenum)fmt, 1);
+			}
+			else
+			{
+				tex.byteSize += RDCMAX(1U, tex.width>>m)*RDCMAX(1U, tex.height>>m)*RDCMAX(1U, tex.depth>>m)*
+													tex.format.compByteWidth*tex.format.compCount;
+			}
+		}
+	}
 
 	return tex;
 }
@@ -495,7 +517,6 @@ FetchBuffer GLReplay::GetBuffer(ResourceId id)
 	gl.glBindBuffer(res.curType, res.resource.name);
 
 	ret.structureSize = 0;
-	GLNOTIMP("Not fetching structure size (if there's an equivalent)");
 
 	ret.creationFlags = 0;
 	switch(res.curType)
diff --git a/renderdoc/driver/gl/gl_resources.cpp b/renderdoc/driver/gl/gl_resources.cpp
index c1e07b6f7..8758f5c74 100644
--- a/renderdoc/driver/gl/gl_resources.cpp
+++ b/renderdoc/driver/gl/gl_resources.cpp
@@ -25,10 +25,31 @@
 
 #include "gl_resources.h"
 
-size_t GetByteSize(GLsizei w, GLsizei h, GLsizei d, GLenum format, GLenum type, int level, int align)
+size_t GetByteSize(GLsizei w, GLsizei h, GLsizei d, GLenum format, GLenum type, int align)
 {
 	size_t elemSize = 0;
 
+	GLsizei alignMask = ~0x0;
+	GLsizei alignAdd = 0;
+	switch(align)
+	{
+		default:
+		case 1:
+			break;
+		case 2:
+			alignMask = ~0x1;
+			alignAdd = 1;
+			break;
+		case 4:
+			alignMask = ~0x3;
+			alignAdd = 3;
+			break;
+		case 8:
+			alignMask = ~0x7;
+			alignAdd = 7;
+			break;
+	}
+
 	switch(type)
 	{
 		case eGL_UNSIGNED_BYTE:
@@ -47,19 +68,28 @@ size_t GetByteSize(GLsizei w, GLsizei h, GLsizei d, GLenum format, GLenum type,
 			break;
 		case eGL_UNSIGNED_BYTE_3_3_2:
 		case eGL_UNSIGNED_BYTE_2_3_3_REV:
-			return w*h*d;
+			return ((w + alignAdd) & alignMask)*h*d;
 		case eGL_UNSIGNED_SHORT_5_6_5:
 		case eGL_UNSIGNED_SHORT_5_6_5_REV:
 		case eGL_UNSIGNED_SHORT_4_4_4_4:
 		case eGL_UNSIGNED_SHORT_4_4_4_4_REV:
 		case eGL_UNSIGNED_SHORT_5_5_5_1:
 		case eGL_UNSIGNED_SHORT_1_5_5_5_REV:
-			return w*h*d*2;
+			return ((w*2 + alignAdd) & alignMask)*h*d;
 		case eGL_UNSIGNED_INT_8_8_8_8:
 		case eGL_UNSIGNED_INT_8_8_8_8_REV:
 		case eGL_UNSIGNED_INT_10_10_10_2:
 		case eGL_UNSIGNED_INT_2_10_10_10_REV:
-			return w*h*d*4;
+			return ((w*4 + alignAdd) & alignMask)*h*d;
+		case eGL_DEPTH_COMPONENT16:
+			return ((w*2 + alignAdd) & alignMask)*h*d;
+		case eGL_DEPTH_COMPONENT24:
+		case eGL_DEPTH24_STENCIL8:
+		case eGL_DEPTH_COMPONENT32:
+		case eGL_DEPTH_COMPONENT32F:
+			return ((w*4 + alignAdd) & alignMask)*h*d;
+		case eGL_DEPTH32F_STENCIL8:
+			return ((w*5 + alignAdd) & alignMask)*h*d;
 		default:
 			RDCERR("Unhandled Byte Size type %d!", type);
 			break;
@@ -73,20 +103,20 @@ size_t GetByteSize(GLsizei w, GLsizei h, GLsizei d, GLenum format, GLenum type,
 		case eGL_GREEN_INTEGER:
 		case eGL_BLUE:
 		case eGL_BLUE_INTEGER:
-			return w*h*d*elemSize;
+			return ((w*elemSize + alignAdd) & alignMask)*h*d;
 		case eGL_RG:
 		case eGL_RG_INTEGER:
-			return w*h*d*elemSize*2;
+			return ((w*elemSize*2 + alignAdd) & alignMask)*h*d;
 		case eGL_RGB:
 		case eGL_RGB_INTEGER:
 		case eGL_BGR:
 		case eGL_BGR_INTEGER:
-			return w*h*d*elemSize*3;
+			return ((w*elemSize*3 + alignAdd) & alignMask)*h*d;
 		case eGL_RGBA:
 		case eGL_RGBA_INTEGER:
 		case eGL_BGRA:
 		case eGL_BGRA_INTEGER:
-			return w*h*d*elemSize*4;
+			return ((w*elemSize*4 + alignAdd) & alignMask)*h*d;
 		default:
 			RDCERR("Unhandled Byte Size format %d!", format);
 			break;
diff --git a/renderdoc/driver/gl/gl_resources.h b/renderdoc/driver/gl/gl_resources.h
index 67159c8a5..9d1a656dc 100644
--- a/renderdoc/driver/gl/gl_resources.h
+++ b/renderdoc/driver/gl/gl_resources.h
@@ -29,7 +29,7 @@
 
 #include "driver/gl/gl_common.h"
 
-size_t GetByteSize(GLsizei w, GLsizei h, GLsizei d, GLenum format, GLenum type, int level, int align);
+size_t GetByteSize(GLsizei w, GLsizei h, GLsizei d, GLenum format, GLenum type, int align);
 
 enum GLNamespace
 {
diff --git a/renderdoc/driver/gl/wrappers/gl_texture_funcs.cpp b/renderdoc/driver/gl/wrappers/gl_texture_funcs.cpp
index ac872e91e..025bc44ef 100644
--- a/renderdoc/driver/gl/wrappers/gl_texture_funcs.cpp
+++ b/renderdoc/driver/gl/wrappers/gl_texture_funcs.cpp
@@ -938,7 +938,7 @@ bool WrappedOpenGL::Serialise_glTextureSubImage1DEXT(GLuint texture, GLenum targ
 	GLint rowlen = 0;
 	m_Real.glGetIntegerv(eGL_UNPACK_ROW_LENGTH, &rowlen);
 
-	size_t subimageSize = GetByteSize(rowlen > 0 ? rowlen : Width, 1, 1, Format, Type, Level, align);
+	size_t subimageSize = GetByteSize(rowlen > 0 ? rowlen : Width, 1, 1, Format, Type, align);
 
 	SERIALISE_ELEMENT_BUF(byte *, buf, pixels, subimageSize);
 	
@@ -1012,7 +1012,7 @@ bool WrappedOpenGL::Serialise_glTextureSubImage2DEXT(GLuint texture, GLenum targ
 	GLint imgheight = 0;
 	m_Real.glGetIntegerv(eGL_UNPACK_IMAGE_HEIGHT, &imgheight);
 
-	size_t subimageSize = GetByteSize(rowlen > 0 ? rowlen : Width, imgheight > 0 ? imgheight : Height, 1, Format, Type, Level, align);
+	size_t subimageSize = GetByteSize(rowlen > 0 ? rowlen : Width, imgheight > 0 ? imgheight : Height, 1, Format, Type, align);
 
 	SERIALISE_ELEMENT_BUF(byte *, buf, pixels, subimageSize);
 	
@@ -1088,7 +1088,7 @@ bool WrappedOpenGL::Serialise_glTextureSubImage3DEXT(GLuint texture, GLenum targ
 	GLint imgheight = 0;
 	m_Real.glGetIntegerv(eGL_UNPACK_IMAGE_HEIGHT, &imgheight);
 
-	size_t subimageSize = GetByteSize(rowlen > 0 ? rowlen : Width, imgheight > 0 ? imgheight : Height, Depth, Format, Type, Level, align);
+	size_t subimageSize = GetByteSize(rowlen > 0 ? rowlen : Width, imgheight > 0 ? imgheight : Height, Depth, Format, Type, align);
 
 	SERIALISE_ELEMENT_BUF(byte *, buf, pixels, subimageSize);