Streaming Bandwidth Calculator
Every viewer costs egress. A 1080p HLS stream at 5 Mbps to 10,000 concurrent viewers is 50 Gbps of peak throughput — roughly $13,000/month in CDN egress before you pay for encoding or storage. This calculator models the multi-bitrate ladder (each viewer gets the tier their connection can handle), protocol overhead tax, peak concurrency factor, and monthly CDN egress cost across five providers.
🎬 Bitrate Ladder Configuration
Each quality tier serves viewers whose connection can sustain that bitrate. Viewers auto-select the best tier their bandwidth allows. The weighted average bitrate determines total egress. Add or remove tiers to match your encoding ladder.
📡 Deployment Parameters
Stream type and protocol choice determine overhead and egress pattern. Live streaming sustains continuous bandwidth; VOD bursts on play.
How Streaming Bandwidth Actually Works
Streaming bandwidth is not a simple bitrate × viewers multiplication. Three structural factors make the real number different from the napkin math.
1. The Multi-Bitrate Ladder: Not All Viewers Get the Same Stream
Modern streaming uses adaptive bitrate (ABR): the encoder produces 4–6 quality tiers (e.g., 4K at 18 Mbps, 1080p at 6 Mbps, 720p at 3 Mbps, 480p at 1.5 Mbps, 360p at 0.8 Mbps), and each viewer's player selects the highest tier their connection can sustain. Mobile viewers on cellular typically get 480p or 720p. Desktop viewers on fiber get 1080p or 4K. The weighted average bitrate across your viewer distribution is often 40–60% of the top-tier bitrate. If you budget for every viewer at 4K, you'll over-provision by 2–3×.
2. Protocol Overhead: The Bits You Don't See
Every streaming protocol wraps video frames in containers, manifests, and network headers. HLS adds roughly 12–18% overhead from segment indexing (m3u8 playlists, fMP4 headers, TCP retransmission buffers). DASH adds 8–12% (more efficient manifest format). WebRTC adds 3–8% overhead (SRTP encryption with header compression) but is designed for real-time — different tradeoffs. RTMP adds 5–8% but is deprecated for delivery (still used for ingest). A 6 Mbps video stream is actually consuming 6.7–7.0 Mbps of egress after overhead. At scale — 10,000 concurrent viewers — that 12% overhead means paying for an extra 7 Mbps × 10,000 = 70 Gbps of phantom bandwidth.
3. Peak vs Average: The Concurrency Multiplier
Your average concurrent viewership is not your peak. A typical live event has a peak-to-average ratio of 2×–4× (a 100K average audience peaks at 250K–400K during key moments). CDNs bill on the 95th percentile of peak throughput, not the average. If you provision for average, you'll be congested for 30–60% of the event. If you provision for peak, you're paying for capacity that's idle most of the time. The peak concurrency factor in this calculator lets you model both — set it to 1× for steady-state VOD delivery, or 2.5× for a live sports event.
Live vs VOD: Different Math
| Dimension | Live Streaming | VOD |
|---|---|---|
| Egress formula | peak_viewers × weighted_bitrate × hours × 3600 | plays × avg_watch_sec × weighted_bitrate |
| Bandwidth pattern | Continuous, spikey (event-driven) | Burst on play, idle between |
| Cost driver | Peak throughput (95th percentile) | Total bytes transferred |
| Protocol choice | HLS or DASH (5–30s latency OK) | HLS, DASH, or progressive download |
| CDN recommendation | Cloudflare or Fastly (high peak capacity) | BunnyCDN or CloudFront (low $/GB) |
For mixed deployments (live events + VOD library), model each separately and sum the costs. A platform that streams 4 live events per month at 50K peak viewers plus a VOD library with 2M monthly plays has fundamentally different economics from a pure-VOD Netflix clone or a pure-live Twitch competitor. Use the stream type selector above to switch modes and compare.
CDN Egress Pricing Reality
CDN egress is the dominant cost in streaming — often 80–90% of the total bill. Storage is cheap (pennies per GB per month). Encoding is a fixed per-minute cost. Egress scales linearly with every viewer and every second of watch time. Here's the effective per-GB cost at two volume tiers:
| Provider | ~50 TB/mo | ~500 TB/mo | ~2 PB/mo | Notes |
|---|---|---|---|---|
| CloudFront | $0.085/GB | $0.06/GB | $0.02/GB | Tiers by region. NA/EU listed. Free tier: 1 TB/mo × 12 months. |
| Cloudflare | $0.00–0.01 | ~$0.005 | ~$0.003 | Free plan: unlimited egress (within ToS). Enterprise: negotiated. |
| Fastly | $0.12/GB | $0.08/GB | $0.04/GB | Premium. Low latency. WASM@Edge. Worth it at scale for live. |
| BunnyCDN | $0.01/GB | $0.005/GB | $0.002/GB | Volume tiers: Standard ($0.01) → Volume ($0.005) → High Volume. |
| KeyCDN | $0.04/GB | $0.02/GB | $0.01/GB | Pay-as-you-go. No commit. 33 PoPs (fewer than competitors). |
Sources: Vendor public pricing pages accessed July 2026. Volume tiers are approximate — actual pricing depends on region mix, commit level, and negotiation. Cloudflare's free-tier unlimited egress has a fair-use clause; at non-streaming volumes it's rarely enforced, but streaming workloads should clarify directly with Cloudflare.
Pricing Basis, Sources & Assumptions
Every rate on this page is a published vendor list price — no negotiated discounts, private pricing, or credit offsets. Totals are in USD and exclude tax. Rates were last checked against the sources below on .
| Pricing input | Basis used on this page |
|---|---|
| Region | North America / Europe for the CDN rate table, which is what CloudFront, Fastly and KeyCDN publish as their entry-tier region. Cloudflare and Bunny quote a single global rate rather than a region-specific one. |
| Currency | USD — on-demand list price, tax excluded |
| Last checked | — The rate ranges in the CDN comparison table — CloudFront $0.02–0.085/GB, Cloudflare $0.005–0.02/GB, Fastly $0.08–0.12/GB, BunnyCDN $0.005–0.03/GB, KeyCDN $0.01–0.04/GB — were re-checked against the linked vendors' price pages on this date. |
Modelling assumptions
- Egress volume = bitrate × concurrent viewers × watch time. The table formats are per viewer-hour, so the bitrate input is the only lever on volume.
- The ranges shown are entry-tier to volume-tier list prices. The low end of each range is reached only at committed volume, so a first-year bill should be modelled at the high end.
- Peak concurrency, not average, sizes the provisioned capacity; the concurrency factor input converts the average to a peak.
- VOD play counts and live concurrency are modelled separately because they have different concurrency shapes.
- Volumes are decimal, and CDN billing is per GB delivered — the same bytes a viewer receives, not the encoding source file.
What this model excludes
- Transcoding and packaging, which often costs more than delivery for a large library.
- Origin storage and origin egress behind the CDN.
- DRM licensing, per-request token issuance, and player licensing.
- Live contribution feeds (the uplink into the encoder), which are billed at a different rate from viewer delivery.
- Committed-use agreements and private pricing, which can move the effective rate well below the published range.
Sources
- AWS (2026). "Amazon CloudFront Pricing." Tiered edge delivery rates used for the CloudFront row. aws.amazon.com
- Cloudflare (2026). "Cloudflare Plans." Flat-rate CDN pricing underlying the Cloudflare row. cloudflare.com
- Fastly (2026). "Fastly Pricing." Published delivery rates for the Fastly row. fastly.com
- Bunny (2026). "Bunny CDN Pricing." Per-region delivery rates for the BunnyCDN row. bunny.net
- KeyCDN (2026). "KeyCDN Pricing." Published delivery rates for the KeyCDN row. keycdn.com
- AWS (2026). "CloudFront Live Streaming." How live video is packaged and delivered through the CDN. docs.aws.amazon.com
Vendor list prices change without notice — re-check the linked pages before committing spend. jslet takes no vendor sponsorship and carries no affiliate links; see about.