A/B Testing Hosting Cost Per-User Formula
Learn how monthly A/B testing hosting cost, annual cost, bandwidth, storage, and cost per active user are calculated.
This formula estimates the recurring cost of hosting an A/B testing or feature-flag setup and allocates that cost across monthly active users. It combines fixed infrastructure and platform charges with estimated bandwidth and storage costs, helping teams create a comparable per-user planning estimate.
- 100% Free
- No Sign-Up Required
- Private & Secure
- Mobile Friendly
Monthly Hosting Cost Per Active User
Where:
Add fixed hosting and A/B testing platform costs to metered bandwidth and storage charges, then divide the monthly total by the number of active users.
Variables Explained
| Variable | What It Means | Unit |
|---|---|---|
| U - Monthly active users | Unique users who participate in or are tracked by experiments during the month. | number |
| B - Base monthly hosting cost | Recurring fixed infrastructure costs, such as application hosting, servers, or managed databases. | currency |
| P - A/B testing platform cost | Recurring monthly experimentation or feature-flag platform charge. | currency |
| BW - Bandwidth per user | Average monthly data transfer attributable to one active user, entered in MB. | MB |
| Rbw - Bandwidth rate per GB | Provider charge for each GB of metered outbound data transfer. | currency |
| S - Storage per user | Average experiment, event, or user data stored for one active user, entered in MB. | MB |
| Rs - Storage rate per GB | Monthly provider charge for each GB of stored data. | currency |
Step-by-Step Calculation
Estimate total monthly bandwidth
Multiply active users by average bandwidth per user, then convert MB to GB.
totalBandwidthGb = monthlyActiveUsers * bandwidthPerUser / 1024
Calculate monthly bandwidth cost
Apply the provider's per-GB bandwidth rate to the estimated transfer volume.
bandwidthCost = totalBandwidthGb * bandwidthRatePerGb
Estimate total stored data
Multiply active users by stored data per user and convert the result from MB to GB.
totalStorageGb = monthlyActiveUsers * storagePerUser / 1024
Calculate monthly storage cost
Apply the monthly storage rate to the estimated storage volume.
storageCost = totalStorageGb * storageRatePerGb
Calculate total monthly hosting cost
Combine fixed hosting, platform, bandwidth, and storage costs.
monthlyHostingCost = baseHostingCost + abTestingPlatformCost + bandwidthCost + storageCost
Calculate cost per active user
Divide the total monthly estimate by monthly active users.
costPerUser = monthlyHostingCost / monthlyActiveUsers
Annualize the monthly estimate
Multiply the monthly estimate by 12 when traffic and prices are assumed to remain unchanged.
annualHostingCost = monthlyHostingCost * 12
Worked example: 10,000 active users per month
Total bandwidth
10,000 × 5 ÷ 1,024
48.83 GB
Bandwidth cost
48.83 × $0.09
$4.39
Total storage
10,000 × 2 ÷ 1,024
19.53 GB
Storage cost
19.53 × $0.02
$0.39
Monthly hosting cost
$50.00 + $100.00 + $4.39 + $0.39
$154.79
Cost per active user
$154.79 ÷ 10,000
$0.0155 per user per month
Annual hosting cost
$154.79 × 12
$1,857.48
Final Result
Estimated A/B testing hosting cost: $154.79 per month, about $0.02 per active user per month, or $1,857.48 per year.
Assumptions
- ✓Each monthly active user generates the same average bandwidth and storage usage.
- ✓Bandwidth and storage inputs are treated as MB per user and are converted using 1,024 MB per GB.
- ✓Base hosting and platform costs are recurring monthly amounts.
- ✓Bandwidth and storage rates represent the effective charges after any included allowances you choose to account for.
- ✓The annual estimate assumes user volume, usage patterns, and prices stay constant for 12 months.
Limitations
- !Actual provider invoices can differ because of regional pricing, request charges, compute usage, taxes, support plans, and other fees not included here.
- !User activity is rarely uniform; a small group of highly active users can create more transfer or storage than the average suggests.
- !The estimate does not model traffic spikes, autoscaling thresholds, data retention schedules, or one-time implementation work.
- !Platform pricing may depend on tracked events, seats, experiment volume, or feature usage rather than only active users.
Common Mistakes to Avoid
Entering GB per user when the calculator expects bandwidth and storage values in MB.
Leaving out the monthly experimentation platform subscription when estimating the full operating cost.
Using total site traffic instead of users who are actually exposed to or tracked by experiments.
Applying a bandwidth rate even though the expected usage is fully covered by an included allowance.
Treating the annual result as a forecast despite expected traffic growth or changing cloud prices.
Related Formulas
Frequently Asked Questions
How is A/B testing cost per user calculated?
The calculator divides total estimated monthly hosting cost by monthly active users. Total cost includes fixed hosting, platform fees, estimated bandwidth charges, and estimated storage charges.
Why does the formula divide by 1,024?
Bandwidth and storage are entered in MB per user. Dividing by 1,024 converts the total from MB to GB before applying a per-GB rate.
What costs should be included in base hosting cost?
Include recurring fixed infrastructure charges that support the testing setup, such as application hosting, servers, managed databases, or fixed cloud plans.
Can bandwidth and storage rates be zero?
Yes. A zero rate is appropriate when the relevant usage is fully included in your plan or you do not want to estimate a separate metered charge.
Does the formula include engineering labor?
No. It estimates recurring hosting and platform-related costs only. Add labor, implementation, analytics, or compliance costs separately if they matter to your budget.
Ready to calculate your result?
Use the calculator to get instant results with your own inputs.