How is the redundancy overhead calculated?

It is the share of traffic you send to the more expensive secondary provider multiplied by its price premium over the primary, applied to your monthly spend. Sending 20% of traffic to a provider that costs 15% more adds 3% to your bill.

How is the avoided downtime cost estimated?

Single-provider expected downtime per month equals downtime probability times minutes in a month, times your cost per minute. Redundancy is assumed to cut that exposure sharply because a failover provider absorbs the outage.

What downtime probability should I use?

A provider advertising 99.9% uptime implies ~0.1% downtime. Translate the SLA into a probability — 99.9% is 0.001, 99.99% is 0.0001 — or use your own observed incident history if you have it.

Is my data sent anywhere?

No. The planner runs entirely in your browser. Nothing you enter is uploaded, stored, or logged.

Does redundancy fully eliminate downtime cost?

No. Failover takes time, both providers can share an upstream dependency, and routing logic can fail. The tool models a strong but not perfect reduction, which is why some residual downtime cost remains.

Provider Redundancy Cost Planner

Is multi-provider redundancy worth the cost?

Running on a single LLM provider is cheapest until that provider has an outage — then every minute of downtime costs you revenue, SLA credits, or churn. Routing a slice of traffic to a second provider buys resilience but adds cost. This planner puts the redundancy overhead next to the expected downtime cost it avoids so you can make the call with numbers.

How it works

The overhead is the premium you pay to send part of your traffic to a pricier secondary provider:

overhead = monthly_spend × secondary_traffic_share × price_premium

The avoided loss is your single-provider expected downtime cost, which redundancy largely removes:

single_provider_downtime_cost = downtime_probability
                              × minutes_per_month
                              × cost_per_minute

If avoided loss exceeds overhead, redundancy pays for itself.

Tips for a sound decision

Use a realistic per-minute cost. Include lost revenue, SLA penalties, and support load — not just compute. This number dominates the result.
Don’t assume perfect failover. Shared upstreams and slow detection mean redundancy reduces, not eliminates, downtime cost.
Right-size the secondary share. You rarely need a 50/50 split; a small warm standby plus fast failover often captures most of the benefit at a fraction of the overhead.