diff --git a/Cargo.toml b/Cargo.toml
index 5ea3804..19871c7 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -139,6 +139,7 @@ reth-ipc = { git = "https://github.com/paradigmxyz/reth", tag = "v1.8.2", option
 
 # Reth-optimism dependencies (optional)
 op-alloy = { version = "0.20.0", features = ["full"], optional = true }
+op-alloy-flz = "0.13.1"
 reth-optimism-node = { git = "https://github.com/paradigmxyz/reth", tag = "v1.8.2", optional = true }
 reth-optimism-chainspec = { git = "https://github.com/paradigmxyz/reth", tag = "v1.8.2", optional = true }
 reth-optimism-forks = { git = "https://github.com/paradigmxyz/reth", tag = "v1.8.2", optional = true }
diff --git a/src/payload/exec.rs b/src/payload/exec.rs
index 6137d05..6d9ba54 100644
--- a/src/payload/exec.rs
+++ b/src/payload/exec.rs
@@ -428,15 +428,15 @@ impl<P: PlatformWithRpcTypes> IntoExecutable<P, Variant<7>>
 #[derive(Debug, Clone, PartialEq)]
 pub struct ExecutionResult<P: Platform> {
 	/// The executable used to produce this result.
-	source: Executable<P>,
+	pub(crate) source: Executable<P>,
 
 	/// For transactions this is guaranteed to be a single-element vector,
 	/// for bundles this is guaranteed to be a vector of results for each
 	/// transaction in the bundle.
-	results: Vec<types::TransactionExecutionResult<P>>,
+	pub(crate) results: Vec<types::TransactionExecutionResult<P>>,
 
 	/// The aggregated state executing all transactions from the source.
-	state: BundleState,
+	pub(crate) state: BundleState,
 }
 
 impl<P: Platform> ExecutionResult<P> {
diff --git a/src/platform/optimism/ext.rs b/src/platform/optimism/ext.rs
new file mode 100644
index 0000000..b84ca23
--- /dev/null
+++ b/src/platform/optimism/ext.rs
@@ -0,0 +1,84 @@
+use {
+	crate::{alloy, prelude::*, reth},
+	alloy::eips::Encodable2718,
+	op_alloy_flz,
+	reth::api::NodeTypes,
+};
+
+pub trait ExecutionResultOpExt<P: Platform> {
+	/// Data availability bytes used by this execution.
+	fn da_bytes_used(&self) -> u64;
+}
+
+impl<P: Platform> ExecutionResultOpExt<P> for ExecutionResult<P>
+where
+	P: Platform<
+		NodeTypes: NodeTypes<
+			ChainSpec = types::ChainSpec<Optimism>,
+			Primitives = types::Primitives<Optimism>,
+			Payload = types::PayloadTypes<Optimism>,
+		>,
+	>,
+{
+	fn da_bytes_used(&self) -> u64 {
+		self
+			.source
+			.transactions()
+			.iter()
+			.map(|tx| {
+				op_alloy_flz::tx_estimated_size_fjord_bytes(
+					tx.encoded_2718().as_slice(),
+				)
+			})
+			.sum()
+	}
+}
+
+pub trait SpanOpExt<P: Platform> {
+	/// Returns the total data availability bytes used by all checkpoints in this
+	/// span
+	fn da_bytes_used(&self) -> u64;
+}
+
+impl<P: Platform> SpanOpExt<P> for Span<P>
+where
+	P: Platform<
+		NodeTypes: NodeTypes<
+			ChainSpec = types::ChainSpec<Optimism>,
+			Primitives = types::Primitives<Optimism>,
+			Payload = types::PayloadTypes<Optimism>,
+		>,
+	>,
+{
+	fn da_bytes_used(&self) -> u64 {
+		self.iter().map(CheckpointOpExt::da_bytes_used).sum()
+	}
+}
+
+pub trait CheckpointOpExt<P: Platform> {
+	/// Data availability bytes used by this checkpoint.
+	fn da_bytes_used(&self) -> u64;
+
+	/// Returns the cumulative data availability bytes used by all checkpoints in
+	/// the history of this checkpoint, including this checkpoint itself.
+	fn cumulative_da_bytes_used(&self) -> u64;
+}
+
+impl<P: Platform> CheckpointOpExt<P> for Checkpoint<P>
+where
+	P: Platform<
+		NodeTypes: NodeTypes<
+			ChainSpec = types::ChainSpec<Optimism>,
+			Primitives = types::Primitives<Optimism>,
+			Payload = types::PayloadTypes<Optimism>,
+		>,
+	>,
+{
+	fn da_bytes_used(&self) -> u64 {
+		self.result().map_or(0, |result| result.da_bytes_used())
+	}
+
+	fn cumulative_da_bytes_used(&self) -> u64 {
+		self.history().da_bytes_used()
+	}
+}
diff --git a/src/platform/optimism/mod.rs b/src/platform/optimism/mod.rs
index 5f63d33..9fd16e9 100644
--- a/src/platform/optimism/mod.rs
+++ b/src/platform/optimism/mod.rs
@@ -20,6 +20,7 @@ use {
 	serde::{Deserialize, Serialize},
 };
 
+pub mod ext;
 mod limits;
 pub use limits::OptimismDefaultLimits;