Uptime SLA downtime minutes calculator

Convert an availability percentage into its theoretical downtime allowance over a period you choose. This is arithmetic from your inputs, not a measurement of a hosting provider or a reading of its contract.

Enter the stated percentage and the period length in days.

Method

Theoretical downtime allowance = period days × 24 × 60 × (100 − availability percentage) ÷ 100. For example, 99.9% over 30 days leaves 0.1% of 43,200 minutes, or 43.2 minutes, under this simple arithmetic model. A 365-day period contains 525,600 minutes.

Choose the period and measurement rules used by the provider's SLA. A contract may define a billing month, scheduled maintenance, measurement locations, qualifying outages, exclusions, reporting steps, and service credits in specific ways. This calculator does not interpret those terms or calculate a credit.

Limits

A stated uptime target is not a report of measured availability, a promise that all visitors can reach the site, or a guarantee of compensation. Actual availability depends on the exact service, how it is measured, and the events included or excluded by its contract. Check the provider's current SLA and preserve the incident evidence and notice deadlines it requires.

Cloudflare's Learning Center describes availability as a percentage over a measurement period and gives annual downtime examples, including 99.9% corresponding to 8 hours, 45 minutes, and 36 seconds over 365 days. That example matches the arithmetic used here; it is not a hosting recommendation or a statement about another provider's SLA. Cloudflare: Application availability (checked November 3, 2026).

For related hosting planning, see the hosting needs estimator, the dated hosting plan cost method, and the host move checklist.