A/B Testing Video Bitrate (Monthly) Calculator
Estimate monthly video data transfer and CDN delivery cost when comparing two video bitrate variants in an A/B test.
Overview
Use this A/B testing video bitrate calculator to estimate how a lower- or higher-bitrate video variant may affect monthly data transfer and CDN delivery costs. Enter expected plays, average watch time, each variant's delivered bitrate, traffic split, and your data-transfer rate.
How it works
The calculator assigns monthly plays between the two variants using the selected traffic split. For each variant, it multiplies plays by average watch time and bitrate, then converts megabits to gigabytes by dividing by eight and by 1,000. It combines both variants' transfer totals and multiplies the result by your CDN cost per GB. The comparison baseline assumes all plays use Variant A.
How to use this calculator
- 1Enter the expected number of video plays in a typical month.
- 2Add the average number of minutes watched per play.
- 3Enter the average delivered bitrate for Variant A and Variant B.
- 4Set the percentage of traffic assigned to Variant B.
- 5Enter your CDN's estimated price per GB.
- 6Review the total transfer, estimated delivery cost, and difference from an all-Variant-A baseline.
Example Calculation
Monthly video plays
100000
Average watch time per play
5
Variant A bitrate
3
Variant B bitrate
5
Traffic assigned to Variant B
50%
CDN cost per GB
$0
Total monthly data transfer
15,000.0 GB
With 100,000 monthly plays split equally between 3 Mbps and 5 Mbps variants and an average watch time of 5 minutes, estimated transfer is 15,000 GB per month. At $0.08 per GB, estimated delivery cost is $1,200, which is about $300 more than serving the 3 Mbps variant to all viewers.
Frequently asked questions
How is video data transfer calculated from bitrate?
The calculator multiplies plays by average watch time in seconds and bitrate in Mbps, then divides by eight to convert bits to bytes and by 1,000 to express the result in decimal GB.
Should I use the encoded bitrate or delivered bitrate?
Use the best estimate of average delivered bitrate. For adaptive bitrate streaming, this may differ from a single encoded rendition because viewers can receive different quality levels.
Why does average watch time matter?
Delivery usage depends on how long viewers actually watch. Using the full video duration can overestimate transfer when viewers often leave early.
What does the traffic split change?
The traffic split determines how many monthly plays receive each bitrate. A larger share assigned to the higher-bitrate variant generally increases total data transfer.
Does this include video storage or transcoding costs?
No. The estimate focuses on viewer data transfer and the entered per-GB delivery rate. Storage, encoding, requests, and platform charges are excluded.
Can I use this calculator for adaptive bitrate streaming?
Yes, if you enter the estimated average bitrate actually delivered to viewers for each test group. Use analytics data when available for a more representative estimate.
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Assumptions and warnings
Assumptions
- Bitrate is treated as the average delivered bitrate for each watched second.
- Average watch time is assumed to be the same for both variants.
- Data transfer is calculated in decimal gigabytes, where 1 GB equals 1,000 MB.
- The CDN cost per GB is assumed to apply equally to all delivered video data.
- Results estimate delivery transfer only and exclude storage, encoding, request, platform, and minimum-commitment charges.
Warnings
- This calculator provides an estimate only; actual delivery usage can vary with adaptive streaming, caching, device type, and viewer behavior.
- Check your CDN pricing terms for regional rates, free allowances, request fees, and other charges before setting a budget.