diff --git a/tinygrad/codegen/gpu.py b/tinygrad/codegen/gpu.py
index 7de2823a04..d1d355d8d8 100644
--- a/tinygrad/codegen/gpu.py
+++ b/tinygrad/codegen/gpu.py
@@ -341,4 +341,4 @@ class GPUCodegen(ASTKernel):
     return ASTRunner(function_name, prg.replace("KERNEL_NAME_PLACEHOLDER", function_name), self.bufs_to_delete,
       list(self.output_shape[::-1]) if len(self.output_shape) > 0 else [1],
       (self.group_for_reduce[::-1] + [1]*(len(self.output_shape)-len(self.group_for_reduce))) if self.group_for_reduce else None,
-      op_estimate=self.info.flops, mem_estimate=sum(4*prod(x._base_shape) for x in self.bufs if x is not None))
+      op_estimate=self.info.flops, mem_estimate=sum(x.dtype.itemsize*prod(x._base_shape) for x in self.bufs if x is not None))
diff --git a/tinygrad/codegen/llvm.py b/tinygrad/codegen/llvm.py
index 420c473d19..db79b008af 100644
--- a/tinygrad/codegen/llvm.py
+++ b/tinygrad/codegen/llvm.py
@@ -212,4 +212,4 @@ class LLVMCodegen(ASTKernel):
     loop_entry[-1].branch(loop_exit[-1]._block)
     loop_exit[0].ret_void()
 
-    return ASTRunner('exec', str(module), op_estimate=self.info.flops, mem_estimate=sum(4*prod(x._base_shape) for x in self.bufs))
+    return ASTRunner('exec', str(module), op_estimate=self.info.flops, mem_estimate=sum(x.dtype.itemsize*prod(x._base_shape) for x in self.bufs))