diff --git a/include/rtc/datachannel.hpp b/include/rtc/datachannel.hpp
index 9a0e6c8..64e5009 100644
--- a/include/rtc/datachannel.hpp
+++ b/include/rtc/datachannel.hpp
@@ -46,6 +46,9 @@ public:
 	void send(const byte *data, size_t size);
 	std::optional<std::variant<binary, string>> receive();
 
+	size_t available() const;
+	size_t availableSize() const;
+
 	unsigned int stream() const;
 	string label() const;
 	string protocol() const;
@@ -69,6 +72,7 @@ private:
 	std::atomic<bool> mIsClosed = false;
 
 	Queue<message_ptr> mRecvQueue;
+	std::atomic<size_t> mRecvSize = 0;
 
 	friend class PeerConnection;
 };
diff --git a/src/datachannel.cpp b/src/datachannel.cpp
index 3a901d4..d8f330c 100644
--- a/src/datachannel.cpp
+++ b/src/datachannel.cpp
@@ -118,9 +118,11 @@ std::optional<std::variant<binary, string>> DataChannel::receive() {
 			break;
 		}
 		case Message::String:
+			mRecvSize -= message->size();
 			return std::make_optional(
 			    string(reinterpret_cast<const char *>(message->data()), message->size()));
 		case Message::Binary:
+			mRecvSize -= message->size();
 			return std::make_optional(std::move(*message));
 		}
 	}
@@ -128,6 +130,10 @@ std::optional<std::variant<binary, string>> DataChannel::receive() {
 	return nullopt;
 }
 
+size_t DataChannel::available() const { return mRecvQueue.size(); }
+
+size_t DataChannel::availableSize() const { return mRecvSize; }
+
 unsigned int DataChannel::stream() const { return mStream; }
 
 string DataChannel::label() const { return mLabel; }
@@ -197,6 +203,7 @@ void DataChannel::incoming(message_ptr message) {
 	}
 	case Message::String:
 	case Message::Binary:
+		mRecvSize += message->size();
 		mRecvQueue.push(message);
 		triggerAvailable(mRecvQueue.size());
 		break;