A/B Testing Database Storage (Monthly) Calculator
Estimate the monthly database storage generated by A/B testing data based on traffic, events, record size, replication, indexing overhead, and retention.
Overview
This A/B testing database storage calculator estimates the data your experiment program adds each month. Enter your monthly traffic, the share enrolled in experiments, records captured per participant, average record size, replication, and database overhead to plan storage capacity.
How it works
The calculator first estimates how many visitors enter experiments, then multiplies that number by the average records written per participant. It multiplies the resulting record count by average record size, then adds the impact of replicated copies and index or metadata overhead. The final value is converted from KB to GB. Retained storage is estimated by multiplying the monthly storage generation by the selected retention period.
How to use this calculator
- 1Enter the number of visitors you track each month.
- 2Set the percentage of visitors included in active experiments.
- 3Estimate the average number of database records captured for each experiment participant.
- 4Enter the average size of one record in KB.
- 5Add your replication factor and estimated index or metadata overhead.
- 6Choose a retention period and review the monthly and retained storage estimates.
Example Calculation
Monthly visitors
100000
Traffic included in experiments
50%
Tracked records per experiment visitor
10
Average record size
0.5
Database replication factor
3
Index and metadata overhead
30%
Data retention period
12
Estimated monthly storage
0.93 GB
This setup creates about 500,000 tracked records per month and requires approximately 0.93 GB of database storage monthly. Keeping 12 months of data requires about 11.16 GB, before allowing for backups or extra capacity headroom.
Frequently asked questions
What A/B testing data should I include in the record count?
Include experiment assignments, exposure events, outcome or conversion events, feature-flag evaluations, and any participant-level metrics stored in the database.
Does adding more A/B test variants always increase storage?
Not necessarily. If the same total audience is split among more variants and each participant produces the same records, total storage can stay similar. Storage rises when more variants create additional events, attributes, or analysis records.
Why is database storage higher than raw event data?
Databases commonly need extra space for indexes, metadata, internal storage structures, and replicated copies. The overhead input helps account for these costs.
Should I include backups in this estimate?
This calculator estimates primary database storage and replicas. Add separate capacity for snapshots, backups, exports, analytics warehouses, and disaster-recovery copies if applicable.
How much storage headroom should I plan?
The appropriate buffer depends on your platform and growth rate. Consider additional capacity for traffic peaks, new tracking fields, temporary migrations, and operational requirements.
Can compression reduce the estimate?
Yes. Compression can reduce stored size, but the result depends on the data format, database engine, index design, and how repetitive the data is. Use a smaller average record size if you have measured compressed storage.
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Assumptions and warnings
Assumptions
- Each visitor included in experiments generates the same average number of stored records.
- Average record size is measured before index, metadata, and replication costs are added.
- Traffic, event volume, and record size are assumed to remain consistent from month to month.
- The retention estimate assumes retained data is not compressed, archived, or deleted early.
- Storage is shown using binary units, where 1 GB equals 1,048,576 KB.
Warnings
- This calculator provides a capacity-planning estimate only; actual database use can vary with schema design, compression, indexing, sharding, and provider storage methods.
- Allow additional headroom for traffic spikes, new experiments, operational logs, backups, and migration activity.