Server Uptime Percentage Calculator
Observed uptime and SLA downtime allowance from a user-defined period and explicit maintenance rules.
A QUICK WALKTHROUGH
How to use this tool
- Name scenarios and enter the period or backup schedule.
- Choose the calculation and eligibility or dependency model, then enter quantities with units.
- Calculate and inspect every trace before copying or downloading the fixed report.
Model
Uptime = (effective period − eligible downtime) / effective period × 100. SLA allowance = effective period × (1 − target / 100); remaining budget = allowance − actual downtime. Intervals are half-open [start,end). Overlaps and touching intervals form one union. Strict UTC dates use elapsed seconds, never a presumed calendar month. Zero effective duration leaves the percentages undefined. In SLA mode, an empty actual downtime field produces allowance only. Observed mode accepts an empty SLA target; SLA mode requires a target from 0 to 100%. Direct downtime must be the user-provided eligible amount after any excluded maintenance. Its intersection with maintenance cannot be inferred from an aggregate duration.
Mode
No service query, contract credit or implicit month length. Direct downtime already excludes maintenance; interval mode subtracts the maintenance union once. Observed mode accepts an empty SLA target; SLA mode requires a target from 0 to 100%. Direct downtime must be the user-provided eligible amount after any excluded maintenance. Its intersection with maintenance cannot be inferred from an aggregate duration.
Results
Exact fractions; display decimals are rounded. All processing stays in this browser. Maximum 10 scenarios and 200 events/interval rows per scenario; larger input is rejected. Decimal input: up to 300 characters; signs and a decimal point only, no scientific notation.Scenario names: 1–200 characters.
GOOD TO KNOW
Common questions
Model?
No service query, contract credit or implicit month length. Direct downtime already excludes maintenance; interval mode subtracts the maintenance union once. Observed mode accepts an empty SLA target; SLA mode requires a target from 0 to 100%. Direct downtime must be the user-provided eligible amount after any excluded maintenance. Its intersection with maintenance cannot be inferred from an aggregate duration.
Invalid or missing value; check units, ranges and row format.?
Maximum 10 scenarios and 200 events/interval rows per scenario; larger input is rejected. Decimal input: up to 300 characters; signs and a decimal point only, no scientific notation.Scenario names: 1–200 characters.