diff --git a/pw_bytes/BUILD b/pw_bytes/BUILD
index baa3389..1e71763 100644
--- a/pw_bytes/BUILD
+++ b/pw_bytes/BUILD
@@ -30,6 +30,7 @@
     hdrs = [
         "public/pw_bytes/byte_builder.h",
         "public/pw_bytes/span.h",
+        "public/pw_bytes/endianness.h",
     ],
     includes = ["public"],
     deps = [
diff --git a/pw_bytes/BUILD.gn b/pw_bytes/BUILD.gn
index ab0ca28..d211198 100644
--- a/pw_bytes/BUILD.gn
+++ b/pw_bytes/BUILD.gn
@@ -29,6 +29,7 @@
   public = [
     "public/pw_bytes/byte_builder.h",
     "public/pw_bytes/span.h",
+    "public/pw_bytes/endianness.h",
   ]
   sources = [ "byte_builder.cc" ]
   public_deps = [
diff --git a/pw_bytes/public/pw_bytes/endianness.h b/pw_bytes/public/pw_bytes/endianness.h
new file mode 100644
index 0000000..69da843
--- /dev/null
+++ b/pw_bytes/public/pw_bytes/endianness.h
@@ -0,0 +1,98 @@
+// Copyright 2020 The Pigweed Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License"); you may not
+// use this file except in compliance with the License. You may obtain a copy of
+// the License at
+//
+//     https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+// WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+// License for the specific language governing permissions and limitations under
+// the License.
+#pragma once
+
+#include <cstddef>
+#include <cstring>
+#include <span>
+
+#include "pw_bytes/byte_builder.h"
+
+namespace pw {
+
+enum class IntSize { kUint8, kUint16, kUint32, kUint64 };
+
+size_t GetIntSize(IntSize int_size) {
+  if (int_size == IntSize::kUint8) {
+    return sizeof(uint8_t);
+  } else if (int_size == IntSize::kUint16) {
+    return sizeof(uint16_t);
+  } else if (int_size == IntSize::kUint32) {
+    return sizeof(uint32_t);
+  } else if (int_size == IntSize::kUint64){
+    return sizeof(uint64_t);
+  } else {
+    return 0;  // Indicate an error
+  }
+}
+
+void GetEndian(ConstByteSpan bytes,
+               void* value,
+               IntSize int_size,
+               ByteOrder kEndianness) {
+  if (int_size == IntSize::kUint8) {
+    ByteBuffer<1> bb;
+    bb.append(bytes);
+    auto it = bb.begin();
+    *static_cast<uint8_t*>(value) = it.ReadUint8();
+  } else if (int_size == IntSize::kUint16) {
+    ByteBuffer<2> bb;
+    bb.append(bytes);
+    auto it = bb.begin();
+    *static_cast<uint16_t*>(value) = it.ReadUint16(kEndianness);
+  } else if (int_size == IntSize::kUint32) {
+    ByteBuffer<4> bb;
+    bb.append(bytes);
+    auto it = bb.begin();
+    *static_cast<uint32_t*>(value) = it.ReadUint32(kEndianness);
+  } else if (int_size == IntSize::kUint64) {
+    ByteBuffer<8> bb;
+    bb.append(bytes);
+    auto it = bb.begin();
+    *static_cast<uint64_t*>(value) = it.ReadUint64(kEndianness);
+  }
+}
+
+void ConvertToEndian(void* value,
+                     ByteSpan bytes,
+                     IntSize int_size,
+                     ByteOrder kEndianness) {
+  if (int_size == IntSize::kUint8) {
+    ByteBuffer<1> bb;
+    bb.append(value, 1);
+    auto it = bb.begin();
+    uint8_t value_converted = it.ReadUint8();
+    std::memcpy(bytes.data(), &value_converted, sizeof(uint8_t));
+  } else if (int_size == IntSize::kUint16) {
+    ByteBuffer<2> bb;
+    bb.append(value, 2);
+    auto it = bb.begin();
+    uint16_t value_converted = it.ReadUint16(kEndianness);
+    std::memcpy(bytes.data(), &value_converted, sizeof(uint16_t));
+  } else if (int_size == IntSize::kUint32) {
+    ByteBuffer<4> bb;
+    bb.append(value, 4);
+    auto it = bb.begin();
+    uint32_t value_converted = it.ReadUint32(kEndianness);
+    std::memcpy(bytes.data(), &value_converted, sizeof(uint32_t));
+  } else if (int_size == IntSize::kUint64) {
+    ByteBuffer<8> bb;
+    bb.append(value, 8);
+    auto it = bb.begin();
+    uint64_t value_converted = it.ReadUint64(kEndianness);
+    std::memcpy(bytes.data(), &value_converted, sizeof(uint64_t));
+  }
+}
+
+}  // namespace pw
\ No newline at end of file