Rex says
Everyday utility math — the kind you'd otherwise pull up four browser tabs for. I keep it to one clean answer.
Try a scenario
Click to load — tweak from there.Inputs
Result
Pages per on-call shift
14.0
Sustainability assessment
Overloaded — needs attention
On-call shifts per person per month
0.72
Night pages per person per month
3.0
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How to use this
- 1Enter people in rotation.
- 2Enter days per on-call shift.
- 3Enter total pages per week (whole rotation).
- 4Enter % of pages during 10pm-7am (%).
- 5Read your pages per on-call shift on the right — it updates as you type.
- 6Hit Share to keep the scenario or send it to someone.
About this calculator
On-call burnout usually creeps up gradually and is hard to see from inside a single rotation, but it shows up clearly once you compute pages per person per week and compare it against known sustainability thresholds. This calculator takes your team size, rotation length, and total pages per week, and computes pages per person per on-call shift, plus an estimated sleep-disrupting page count based on the share of pages that land during typical off-hours (10pm-7am). Industry guidance from PagerDuty and Google's SRE book generally treats more than 2 pages per on-call shift per week as a sign the rotation needs attention — either through better alert tuning, a larger rotation pool, or follow-the-sun coverage — and more than 1 disruptive night-time page per week per person as a leading indicator of attrition risk within the team.
Worked example
Using the values the calculator loads with:
Inputs
- People in rotation: 6
- Days per on-call shift: 7
- Total pages per week (whole rotation): 14
- % of pages during 10pm-7am: 30 %
Results
- Pages per on-call shift: 14
- Sustainability assessment: Overloaded — needs attention
- On-call shifts per person per month: 0.72
- Night pages per person per month: 3
What each field means
Inputs
- People in rotation
- The people in rotation used in the calculation. Starts at 6 so you have a working example on load.
- Days per on-call shift
- The days per on-call shift used in the calculation. Starts at 7 so you have a working example on load.
- Total pages per week (whole rotation)
- The total pages per week (whole rotation) used in the calculation. Starts at 14 so you have a working example on load.
- % of pages during 10pm-7am (%)
- The % of pages during 10pm-7am used in the calculation, measured in %. Starts at 30 % so you have a working example on load. Accepted range: 0–100 %.
Results
- Pages per on-call shift
- Returned as a decimal number and shown as the headline result. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Sustainability assessment
- Returned as a plain value. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- On-call shifts per person per month
- Returned as a decimal number. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Night pages per person per month
- Returned as a decimal number. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
FAQ
What's a healthy number of pages per on-call week?
Most SRE teams target under 2 actionable pages per person per on-call week as a sustainability ceiling, with anything above that treated as a signal to invest in alert tuning or auto-remediation rather than just adding people to the rotation. If pages are frequent but mostly non-actionable, the fix is alert quality, not headcount.
How many people do I need in a rotation to keep it sustainable?
A common floor is 6-8 engineers per rotation so no one is on-call more than roughly one week in six to eight, giving enough recovery time between shifts. Smaller teams should consider secondary/backup on-call, shared cross-team rotations, or reducing alert volume before adding a punishing 1-in-3 or 1-in-4 rotation cadence.
Does this account for compensation for on-call time?
No, this only measures load, not pay. Many companies pay a flat on-call stipend plus overtime-equivalent pay for actual incident response time; if yours doesn't, high page volume paired with no on-call compensation is one of the strongest predictors of engineer attrition and should be flagged to leadership alongside the load numbers.
Accuracy and limitations
- Estimates assume standard, average conditions — local rules, pricing, and materials vary.
- Results are rounded for readability; add a buffer before ordering, booking, or committing.
- Double-check anything with a real cost attached against a local quote.
Related tools
Cite this calculator
Writing about this topic? Grab a citation — every link helps keep these tools free.
RevenueLab. (2026). On-Call Load Calculator. Retrieved from https://www.revenuelab.fyi/toolbox/oncall-load-calculator
<p>Source: <a href="https://www.revenuelab.fyi/toolbox/oncall-load-calculator" target="_blank" rel="noopener">On-Call Load Calculator — RevenueLab</a> (2026).</p>
Source: [On-Call Load Calculator — RevenueLab](https://www.revenuelab.fyi/toolbox/oncall-load-calculator) (2026).