CloudTrail Storage Calculator
Size CloudTrail data event charges, compressed S3 storage across a retention window, extra trail copies and Lake ingestion.
Inputs
The first copy of management events is free; extra trails are charged.
Estimated Monthly Cost
$54.34
Data Event Cost
$50.00
Extra Trail Copy Cost
$0.00
S3 Storage Cost at Steady State
$4.34
CloudTrail Lake Ingestion Cost
$0.00
Compressed Data Held
188.8GB
Step by step
Values used
Data events per month = 50,000,000 events; Management events per month = 5,000,000 events; Additional trails beyond the first = 0 trails; Average event record size = 1.50 KB; Retention in S3 = 12 months; Compressed size as a share of raw = 20 %; Also ingest into CloudTrail Lake = No; Data event price per 100,000 events = 0.1000 USD; Extra-copy management event price per 100,000 = 2 USD; S3 storage price per GB-month = 0.0230 USD; CloudTrail Lake ingestion price per GB = 2.50 USD
CloudTrail Storage
cost = data events ÷ 100,000 × event price + extra trails × management events ÷ 100,000 × copy price + compressed GB held × S3 price, plus Lake ingestion if enabled.
Retention accumulation
steady-state GB = total events × event KB ÷ 1,048,576 × compressed share × retention months.
Estimated Monthly Cost
= 54.34
Data Event Cost
= 50.00
Extra Trail Copy Cost
= 0.00
S3 Storage Cost at Steady State
= 4.34
CloudTrail Lake Ingestion Cost
= 0.00
Compressed Data Held
= 188.8 GB
How it works
CloudTrail gives you one free copy of management events per account, so the cost almost always comes from data events, which fire once per S3 object or Lambda invocation and can be thousands of times more numerous. Storage grows linearly until the retention window fills, so the steady-state figure is the monthly volume multiplied by the retention months, not just one month. Confirm the current data event and Lake prices for your region. Turning on S3 data events across every bucket is the classic way to add a four-figure monthly line item overnight — scoping them to the buckets and prefixes that actually need an audit trail is what keeps CloudTrail affordable.
Formulas
CloudTrail Storage
cost = data events ÷ 100,000 × event price + extra trails × management events ÷ 100,000 × copy price + compressed GB held × S3 price, plus Lake ingestion if enabled.
- data event
- Object-level or function-level activity such as S3 GetObject or Lambda Invoke
- management event
- Control-plane API call; the first trail copy is free
- steady state GB
- Monthly compressed volume × retention months, once the window is full
Retention accumulation
steady-state GB = total events × event KB ÷ 1,048,576 × compressed share × retention months.
Frequently Asked Questions
How is CloudTrail Storage calculated?
cost = data events ÷ 100,000 × event price + extra trails × management events ÷ 100,000 × copy price + compressed GB held × S3 price, plus Lake ingestion if enabled. CloudTrail gives you one free copy of management events per account, so the cost almost always comes from data events, which fire once per S3 object or Lambda invocation and can be thousands of times more numerous. Storage grows linearly until the retention window fills, so the steady-state figure is the monthly volume multiplied by the retention months, not just one month. Confirm the current data event and Lake prices for your region.
Why does CloudTrail Storage matter?
Turning on S3 data events across every bucket is the classic way to add a four-figure monthly line item overnight — scoping them to the buckets and prefixes that actually need an audit trail is what keeps CloudTrail affordable.
What values do I need to enter?
This calculator takes 11 inputs: Data events per month, Management events per month, Additional trails beyond the first, Average event record size, Retention in S3, Compressed size as a share of raw, Also ingest into CloudTrail Lake, Data event price per 100,000 events, Extra-copy management event price per 100,000, S3 storage price per GB-month, CloudTrail Lake ingestion price per GB. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.
Why are data events so much more expensive than management events?
Volume. Management events are control-plane calls, typically thousands a day. Data events are per object or per invocation, so a single busy bucket or a Lambda handling millions of requests generates orders of magnitude more records — and there is no free copy for them.
Should I use CloudTrail Lake or query the S3 files?
Lake charges a high per-GB ingestion fee but gives SQL over a managed, immutable store with its own retention. Querying the raw S3 JSON with Athena is far cheaper to store and lets you keep the data in your own lifecycle policy, at the cost of building the table and partitions yourself.