diff --git a/sentry-ruby/lib/sentry-ruby.rb b/sentry-ruby/lib/sentry-ruby.rb
index 7c846fb11..5e02e51ae 100644
--- a/sentry-ruby/lib/sentry-ruby.rb
+++ b/sentry-ruby/lib/sentry-ruby.rb
@@ -12,6 +12,7 @@
 require "sentry/utils/logging_helper"
 require "sentry/utils/callback_helper"
 require "sentry/utils/sample_rand"
+require "sentry/utils/latency"
 require "sentry/configuration"
 require "sentry/structured_logger"
 require "sentry/debug_structured_logger"
diff --git a/sentry-ruby/lib/sentry/job_extensions/extension.rb b/sentry-ruby/lib/sentry/job_extensions/extension.rb
index 0b8e5ebf4..9fc7a3cae 100644
--- a/sentry-ruby/lib/sentry/job_extensions/extension.rb
+++ b/sentry-ruby/lib/sentry/job_extensions/extension.rb
@@ -132,8 +132,9 @@ def extract_trace_headers(job:, payload:)
       # @return [Hash] a Hash with any of the keys +:system+ (a String naming
       #   the backend), +:message_id+ (a String), +:destination+ (a String,
       #   such as the queue name), +:receive_latency+ (a Numeric, the
-      #   milliseconds between enqueueing and the start of the job). Empty by
-      #   default.
+      #   milliseconds between enqueueing and the start of the job) and
+      #   +:body_size+ (a non-negative Integer, the size of the message body
+      #   in bytes). Empty by default.
       def messaging_data(job:)
         {}
       end
diff --git a/sentry-ruby/lib/sentry/job_extensions/instrumentation.rb b/sentry-ruby/lib/sentry/job_extensions/instrumentation.rb
index 71a23eee8..95f724658 100644
--- a/sentry-ruby/lib/sentry/job_extensions/instrumentation.rb
+++ b/sentry-ruby/lib/sentry/job_extensions/instrumentation.rb
@@ -10,7 +10,8 @@ class Instrumentation
         system: Span::DataConventions::MESSAGING_SYSTEM,
         message_id: Span::DataConventions::MESSAGING_MESSAGE_ID,
         destination: Span::DataConventions::MESSAGING_DESTINATION_NAME,
-        receive_latency: Span::DataConventions::MESSAGING_MESSAGE_RECEIVE_LATENCY
+        receive_latency: Span::DataConventions::MESSAGING_MESSAGE_RECEIVE_LATENCY,
+        body_size: Span::DataConventions::MESSAGING_MESSAGE_BODY_SIZE
       }.freeze
 
       attr_reader :extension
diff --git a/sentry-ruby/lib/sentry/span.rb b/sentry-ruby/lib/sentry/span.rb
index b53554dc4..407288366 100644
--- a/sentry-ruby/lib/sentry/span.rb
+++ b/sentry-ruby/lib/sentry/span.rb
@@ -50,6 +50,7 @@ module DataConventions
       MESSAGING_DESTINATION_NAME = "messaging.destination.name"
       MESSAGING_MESSAGE_RECEIVE_LATENCY = "messaging.message.receive.latency"
       MESSAGING_MESSAGE_RETRY_COUNT = "messaging.message.retry.count"
+      MESSAGING_MESSAGE_BODY_SIZE = "messaging.message.body.size"
 
       # Time in ms the request spent in the server queue before processing began.
       HTTP_QUEUE_TIME_MS = "http.server.request.time_in_queue"
diff --git a/sentry-ruby/lib/sentry/utils/latency.rb b/sentry-ruby/lib/sentry/utils/latency.rb
new file mode 100644
index 000000000..702735a2f
--- /dev/null
+++ b/sentry-ruby/lib/sentry/utils/latency.rb
@@ -0,0 +1,18 @@
+# frozen_string_literal: true
+
+require "time"
+
+module Sentry
+  module Utils
+    module Latency
+      module_function
+
+      def milliseconds_since(time)
+        return unless time
+
+        time = Time.parse(time) if time.is_a?(String)
+        (Time.now.to_f - time.to_f) * 1000.0
+      end
+    end
+  end
+end
diff --git a/sentry-ruby/spec/sentry/job_extensions/consumer_spec.rb b/sentry-ruby/spec/sentry/job_extensions/consumer_spec.rb
index e4ac37e6b..90b86380c 100644
--- a/sentry-ruby/spec/sentry/job_extensions/consumer_spec.rb
+++ b/sentry-ruby/spec/sentry/job_extensions/consumer_spec.rb
@@ -45,7 +45,7 @@ def capture(consumer, exception = RuntimeError.new("boom"), **options)
 
   def enriching_consumer
     consumer(
-      messaging_data: ->(job:) { { system: "backend", message_id: job.id, destination: job.queue, receive_latency: 42.5 } },
+      messaging_data: ->(job:) { { system: "backend", message_id: job.id, destination: job.queue, receive_latency: 42.5, body_size: 128 } },
       retry_info: ->(job:) { { count: 3, will_retry: true } },
       scope_data: ->(job:) { { contexts: { backend: { "jid" => "backend-jid" } }, tags: { "backend.queue" => "low" }, extra: { size: 12 } } }
     )
@@ -85,6 +85,7 @@ def enriching_consumer
         "messaging.message.id" => "job-1",
         "messaging.destination.name" => "critical",
         "messaging.message.receive.latency" => 42.5,
+        "messaging.message.body.size" => 128,
         "messaging.message.retry.count" => 3
       )
     end
diff --git a/sentry-ruby/spec/sentry/job_extensions/producer_spec.rb b/sentry-ruby/spec/sentry/job_extensions/producer_spec.rb
index cf9f238f2..1f1a28d19 100644
--- a/sentry-ruby/spec/sentry/job_extensions/producer_spec.rb
+++ b/sentry-ruby/spec/sentry/job_extensions/producer_spec.rb
@@ -15,7 +15,7 @@ def producer(**hooks)
 
   def enriching_producer
     producer(
-      messaging_data: ->(job:) { { system: "backend", message_id: job.id, destination: job.queue, receive_latency: 42.5 } },
+      messaging_data: ->(job:) { { system: "backend", message_id: job.id, destination: job.queue, receive_latency: 42.5, body_size: 128 } },
       retry_info: ->(job:) { { count: 3, will_retry: true } }
     )
   end
@@ -59,6 +59,7 @@ def record_span(producer, &enqueue)
         "messaging.message.id" => "job-1",
         "messaging.destination.name" => "critical",
         "messaging.message.receive.latency" => 42.5,
+        "messaging.message.body.size" => 128,
         "messaging.message.retry.count" => 3
       )
     end
diff --git a/sentry-ruby/spec/sentry/utils/latency_spec.rb b/sentry-ruby/spec/sentry/utils/latency_spec.rb
new file mode 100644
index 000000000..9cd24aad8
--- /dev/null
+++ b/sentry-ruby/spec/sentry/utils/latency_spec.rb
@@ -0,0 +1,21 @@
+# frozen_string_literal: true
+
+RSpec.describe Sentry::Utils::Latency do
+  let(:started_at) { Time.utc(2026, 1, 1, 12, 0, 0) }
+
+  around do |example|
+    Timecop.freeze(started_at + 2.5) { example.run }
+  end
+
+  it "measures the milliseconds since a Time" do
+    expect(described_class.milliseconds_since(started_at)).to eq(2_500.0)
+  end
+
+  it "measures the milliseconds since an ISO 8601 String" do
+    expect(described_class.milliseconds_since(started_at.iso8601(3))).to eq(2_500.0)
+  end
+
+  it "measures nothing without a time" do
+    expect(described_class.milliseconds_since(nil)).to be_nil
+  end
+end