Gbps → TB / Day Egress
Sustained 1 Gbps equates to approximately 10.8 TB transferred per 24-hour period. This tool converts between network throughput (Gbps) and daily transfer volume (TB) for cloud egress cost modeling and CDN capacity planning.
Bidirectional Egress Calculator
Convert between sustained Gbps throughput and 24-hour transfer volume in both directions.
Cloud Egress Cost Reference
Estimated monthly cloud egress costs at various throughput levels (pricing approximated).
| Throughput (Gbps) | TB/Month | Est. AWS Cost |
|---|---|---|
| 0.1 | 32.4 | $2,754 |
| 1 | 324 | $26,798 |
| 5 | 1,620 | $133,488 |
| 10 | 3,240 | $263,088 |
| 40 | 12,960 | $1,049,088 |
| 100 | 32,400 | $2,620,488 |
Gbps → TB/Day: The Egress Equation
The conversion is straightforward: 1 Gbps sustained for 24 hours = (1 × 10⁹ bits/s × 86,400 s) ÷ (8 bits/byte × 10¹² bytes/TB) ≈ 10.8 TB/day. This assumes 100% link utilization — in practice, bursty traffic patterns, TCP slow-start, and inter-packet gaps reduce effective throughput by 10–30%.
For cloud egress planning, this is the single most important conversion to internalize. A 10 Gbps Direct Connect link can push up to 3,240 TB/month — at AWS standard egress pricing (~$0.09/GB after the first 10 TB), that's over $263,000/month in data transfer charges alone. Enterprises often discover this only after their first cloud bill shock. Budget egress capacity and costs with this tool before architecting cross-region or hybrid-cloud data pipelines.
Decimal and binary again: 10.8 TB is not 9.83 TiB
1 Gbps sustained for 24 hours is (109 bits/s × 86,400 s) ÷ (8 bits/byte × 1012 bytes/TB) = 10.8 TB/day. In binary units the same traffic is 9.83 TiB/day, because a tebibyte is 1.0995 × 1012 bytes. Cloud billing uses decimal units, storage dashboards usually use binary ones, and a 9% discrepancy between a transfer log and an invoice is almost always this rather than a rounding error.
Worked example: the 50 Mbps line that costs $1,458 a month
Small sustained rates are where this conversion earns its keep, because a continuous trickle becomes a large monthly total. Take a 50 Mbps link running flat out:
50 × 106 bits/s × 2,592,000 s/month ÷ 8 ÷ 1012 = 16.2 TB/month
At AWS standard egress of roughly $0.09/GB that is 16,200 GB × $0.09 ≈ $1,458/month.
Fifty megabits per second is a video stream, a log shipper, a cross-region replication feed — nothing that registers as a capacity problem. The billing unit is the thing to watch, and it accumulates at 10.8 TB per Gbps per day regardless of how unremarkable the instantaneous rate looks.
Asymmetry is the architectural fact
Ingress is free on essentially every major cloud. Egress is metered. That single asymmetry should drive more architecture than it usually does: put data where it will be consumed, replicate toward readers rather than pulling toward a central store, and treat any regularly scheduled cross-boundary pull as a design smell. A nightly job fetching 500 GB from a central region costs about $450/month purely in transfer — the same data pushed to the edge once, or read in place, does not.
Peak-based thinking does not transfer either. Enterprise circuits are often billed on 95th-percentile utilisation, which rewards flattening peaks. Cloud egress is billed on total volume, so flattening a peak changes nothing and reducing the total is the only lever. Teams arriving from network engineering habitually optimise the wrong variable for their first several months on cloud.
What CDN offload actually changes
A CDN does not reduce egress, it relocates it. With a 95% cache hit ratio, origin egress falls twentyfold — a service pushing 100 TB/month to viewers drops to 5 TB/month from origin, about $450/month. But the CDN's own delivery charges are a separate line item, usually on the same order of magnitude. The saving comes from hitting cache and from CDN egress rates sitting below direct object-storage egress — not from making bytes disappear. Planning an offload migration around "95% of traffic goes away" overstates the benefit by the difference between the two rate cards.
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 | US East (N. Virginia) — the $0.09/GB and $0.085/GB AWS internet-egress tiers used for the cost column. |
| Currency | USD — on-demand list price, tax excluded |
| Last checked | — The AWS egress tiers used for the cost column ($0.09 to 10 TB, $0.085 to 50 TB, $0.07 to 150 TB, $0.05 above) were re-checked on this date. |
Modelling assumptions
- The conversion is arithmetic, not empirical: a sustained 1 Gbps carries 86,400 Gb in a 86,400-second day, which is 10.8 TB/day and about 324 TB/month at 30 days.
- Bits and bytes are kept apart deliberately: Gbps is gigabits per second and the result is in bytes, so the ratio carries a factor of 8.
- Volumes are decimal throughout (1 TB = 1,000 GB), matching how cloud egress is billed.
- The rate is sustained throughput, not peak. Link capacity is an upper bound — TCP window limits, round-trip latency, packet loss, and protocol overhead all sit between the interface speed and the useful payload.
- The cost column applies AWS internet-egress pricing to the resulting monthly volume; because that price is tiered, the effective $/GB falls as throughput rises.
What this model excludes
- Port, cross-connect, and Direct Connect charges, and any Transit Gateway attachment hours.
- Peering and interconnect costs, which can replace per-GB egress entirely at scale.
- Retransmissions and the payload overhead of TLS, HTTP headers, and encapsulation.
- CDN offload, which reduces origin egress without reducing the throughput needed at the edge.
Sources
- AWS (2026). "Amazon EC2 Data Transfer Pricing." The tiered internet-egress rates applied to each throughput row. aws.amazon.com
- AWS (2026). "Amazon CloudFront Pricing." Edge delivery rates for when a CDN sits in front of the origin. aws.amazon.com
- AWS (2026). "Amazon S3 Pricing." Object-storage egress context where the transfer originates in S3. 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.