diff --git a/src/sinks/redis.rs b/src/sinks/redis.rs
index 084ff21ffd0e3..611127b4641d0 100644
--- a/src/sinks/redis.rs
+++ b/src/sinks/redis.rs
@@ -290,10 +290,11 @@ fn encode_event(
     transformer.transform(&mut event);
 
     let mut bytes = BytesMut::new();
-    let byte_size = bytes.len();
 
     // Errors are handled by `Encoder`.
     encoder.encode(event, &mut bytes).ok()?;
+
+    let byte_size = bytes.len();
     let value = bytes.freeze();
 
     let event = EncodedEvent::new(RedisKvEntry { key, value }, byte_size, event_byte_size);
diff --git a/src/sinks/vector/sink.rs b/src/sinks/vector/sink.rs
index 09eede27d1844..229867194ddfd 100644
--- a/src/sinks/vector/sink.rs
+++ b/src/sinks/vector/sink.rs
@@ -7,7 +7,7 @@ use tower::Service;
 use vector_common::json_size::JsonSize;
 use vector_core::{
     stream::{BatcherSettings, DriverResponse},
-    ByteSizeOf,
+    ByteSizeOf, EstimatedJsonEncodedSizeOf,
 };
 
 use super::service::VectorRequest;
@@ -20,6 +20,7 @@ use crate::{
 /// Data for a single event.
 struct EventData {
     byte_size: usize,
+    json_byte_size: JsonSize,
     finalizers: EventFinalizers,
     wrapper: EventWrapper,
 }
@@ -30,6 +31,7 @@ struct EventCollection {
     pub finalizers: EventFinalizers,
     pub events: Vec<EventWrapper>,
     pub events_byte_size: usize,
+    pub events_json_byte_size: JsonSize,
 }
 
 pub struct VectorSink<S> {
@@ -48,6 +50,7 @@ where
         input
             .map(|mut event| EventData {
                 byte_size: event.size_of(),
+                json_byte_size: event.estimated_json_encoded_size_of(),
                 finalizers: event.take_finalizers(),
                 wrapper: EventWrapper::from(event),
             })
@@ -57,13 +60,14 @@ where
                     event_collection.finalizers.merge(item.finalizers);
                     event_collection.events.push(item.wrapper);
                     event_collection.events_byte_size += item.byte_size;
+                    event_collection.events_json_byte_size += item.json_byte_size;
                 },
             ))
             .map(|event_collection| {
                 let builder = RequestMetadataBuilder::new(
                     event_collection.events.len(),
                     event_collection.events_byte_size,
-                    JsonSize::new(event_collection.events_byte_size), // this is fine as it isn't being used
+                    event_collection.events_json_byte_size,
                 );
 
                 let encoded_events = proto_vector::PushEventsRequest {