CDN Cost Per GB and Per Gigabyte Guide

Start with a calculator if you need a first-pass estimate, then use this guide to validate the assumptions and catch the billing traps.

This page is the CDN bandwidth-rate page, not the full delivery-bill page: the job is to turn region mix, tiering, and discounts into a defendable blended $/GB assumption.

If you searched for CDN costs per GB, CDN cost per gigabyte, or CDN cost per GB, this is the right starting page. The fastest way to estimate CDN bandwidth spend is a clean $/GB model, but you must normalize region mix and tiered pricing first to avoid under-estimating.

If request fees, origin egress, or provider comparison are starting to matter more than bandwidth alone, go back to the broader pricing pages next.

Guide first or calculator first?

• Use this guide first when you need to turn raw bandwidth data into a defensible blended $/GB.
• Use the calculator first when you already know your monthly GB and effective bandwidth rate.
• Return to comparison mode when provider decisions depend on requests, origin egress, or contract terms too.

Step 1: Get monthly GB delivered

• Use CDN analytics if available.
• If you only have throughput, convert Mbps to GB/month before pricing.
• Model baseline and peak months separately.

Step 2: Apply region mix

• Split traffic by pricing regions (North America, Europe, APAC, etc.).
• Apply the correct $/GB per region and sum the totals.
• If you only have a blended rate, validate it against a real bill.

Step 3: Account for tiered pricing

• Some providers lower $/GB after specific volume tiers.
• Either compute each tier explicitly or use a blended rate for your expected volume.
• Do not use the lowest tier price for the entire month.

Step 4: Check free allowances and discounts

• Subtract free bandwidth before applying $/GB rates.
• Apply committed-use or enterprise discounts if you have them.

Effective $/GB formula (fast sanity check)

• Effective $/GB = total bandwidth charges / total GB delivered.
• Use this to back-calc a blended rate from a real bill, then reuse it for planning.

Example calculation

If you delivered 8,000 GB with $420 of bandwidth charges, your effective rate is $420 / 8,000 = $0.0525 per GB. Use that blended rate for the next month unless your region mix or tier changes.

Validate with a peak scenario

• Peak months often shift region mix and cache hit rate.
• Use a higher GB/month and re-run the tiered pricing math.
• Compare effective $/GB for baseline vs peak so you do not under-budget.

Cache behavior still matters

• Edge GB is billed regardless of hit rate, but cache misses can add origin egress costs.
• If your hit rate drops during deploys or incidents, your total spend can rise even with similar edge GB.

Provider shortcuts for per-GB research

Region mix example

If 60% of your traffic is in North America at $0.05/GB and 40% is in APAC at $0.09/GB, your blended rate is (0.6 x 0.05) + (0.4 x 0.09) = $0.066/GB. That blended rate is what you should use for quick planning.

Validation checklist

• Compare your blended rate to the last invoice to confirm it is realistic.
• Check for traffic shifts to higher priced regions.
• Recalculate after major content changes (video, downloads, or large payloads).

Units and rounding pitfalls

• Some providers bill in decimal GB, others in GiB; confirm before comparing.
• Billing dashboards may round at the line item level, which shifts the blended rate.
• Always compare on the same unit basis when benchmarking.

When $/GB is not enough

• High request volume: request fees can exceed bandwidth spend.
• Low cache hit rate: origin egress can add a second bill.
• Security add-ons: WAF and bot mitigation are request-driven.

What this does not include

• Request fees: often billed per 10k or per 1M requests.
• Origin egress: cache fill billed by your origin provider.
• Log or analytics add-ons: some providers bill these separately.

When to stop using per-GB alone

• When request-heavy traffic starts dominating small object delivery.
• When your regional mix changes enough to move the blended rate materially.
• When provider choice depends on more than bandwidth pricing.

At that point, move to CDN cost comparison or the CDN total-cost calculator.

This page deliberately stays on bandwidth-rate math. It does not replace the full CDN bill page or the request-fee page.

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