Rex says
Money math without the spreadsheet headache. Plug in your numbers and I'll show you exactly where the dollars land.
Try a scenario
Click to load — tweak from there.Inputs
Result
Net annual benefit of PM program
$23,960
Expected annual cost without PM
$58,400
Total annual cost with PM program
$34,440
Residual breakdown cost even with PM
$20,440
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How to use this
- 1Enter unplanned failures per year (no pm).
- 2Enter average repair cost per failure ($).
- 3Enter average downtime per failure (hrs).
- 4Enter cost of downtime per hour (lost production+repair) ($/hr).
- 5Enter annual pm program cost ($).
- 6Enter failure reduction from pm program (%).
- 7Read your net annual benefit of pm program on the right — it updates as you type.
- 8Hit Share to keep the scenario or send it to someone.
About this calculator
Preventive maintenance has a real, predictable cost — parts, labor, and planned production time lost to scheduled service. Skipping it doesn't eliminate that cost, it just converts it into unplanned downtime risk, which is usually more expensive per hour because it happens at random times, often causes secondary damage, and stops production without warning instead of during a scheduled window. This calculator compares annual PM program cost against the expected annual cost of breakdowns without it, using your estimated failure rate reduction from the PM program and the cost per hour of unplanned downtime (which should include lost production value, not just repair cost, since lost throughput is usually the bigger number). The output shows the net financial case for maintaining or increasing your PM investment, which is often the easiest capital argument to win in a plant because the payback is direct and immediate.
Worked example
Using the values the calculator loads with:
Inputs
- Unplanned failures per year (no PM): 8
- Average repair cost per failure: 2200 $
- Average downtime per failure: 6 hrs
- Cost of downtime per hour (lost production+repair): 850 $/hr
- Annual PM program cost: 14000 $
- Failure reduction from PM program: 65 %
Results
- Net annual benefit of PM program: $23,960
- Expected annual cost without PM: $58,400
- Total annual cost with PM program: $34,440
- Residual breakdown cost even with PM: $20,440
What each field means
Inputs
- Unplanned failures per year (no PM)
- The unplanned failures per year (no pm) used in the calculation. Starts at 8 so you have a working example on load.
- Average repair cost per failure ($)
- The average repair cost per failure used in the calculation, measured in $. Starts at 2200 $ so you have a working example on load.
- Average downtime per failure (hrs)
- The average downtime per failure used in the calculation, measured in hrs. Starts at 6 hrs so you have a working example on load.
- Cost of downtime per hour (lost production+repair) ($/hr)
- The cost of downtime per hour (lost production+repair) used in the calculation, measured in $/hr. Starts at 850 $/hr so you have a working example on load.
- Annual PM program cost ($)
- The annual pm program cost used in the calculation, measured in $. Starts at 14000 $ so you have a working example on load.
- Failure reduction from PM program (%)
- The failure reduction from pm program used in the calculation, measured in %. Starts at 65 % so you have a working example on load. Accepted range: 0–100 %.
Results
- Net annual benefit of PM program
- Returned as a money amount in US dollars and shown as the headline result. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Expected annual cost without PM
- Returned as a money amount in US dollars. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Total annual cost with PM program
- Returned as a money amount in US dollars. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Residual breakdown cost even with PM
- Returned as a money amount in US dollars. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
FAQ
How do I estimate downtime cost per hour?
Use lost production value (units per hour that would have been made, times contribution margin per unit) plus any expedited repair, overtime, or rush shipping costs incurred. Most plants find this number is far higher than they initially assume once lost throughput on a bottleneck machine is properly counted, not just the mechanic's labor bill.
What failure reduction percentage is realistic for a new PM program?
Well-implemented PM programs on equipment that previously had little to no scheduled maintenance commonly cut unplanned failures 40-70%. Equipment that's already well maintained will see smaller incremental gains from adding more PM, and past a certain point additional PM spend has diminishing returns.
Does this account for the value of avoiding secondary damage?
Only indirectly, through your repair cost input. Breakdown failures often cascade into secondary damage (a bearing failure that scores a shaft, for example) that a caught-early PM inspection would have avoided at a fraction of the cost — if that's a known risk for your equipment, weight your repair cost input higher to reflect it.
What if the net benefit comes out negative?
That suggests either your PM program cost is too high for the risk profile of that particular asset, or the failure reduction assumption is optimistic. Low-criticality equipment with cheap, fast repairs sometimes genuinely doesn't justify an intensive PM program — run-to-failure can be the economically correct choice for non-critical assets.
Accuracy and limitations
- Results are estimates before tax, fees, and inflation unless an input explicitly covers them.
- Rates are treated as fixed for the whole period — variable-rate products will drift from this projection.
- This is educational maths, not financial advice. Check anything contractual with the lender or your accountant.
Related tools
Cite this calculator
Writing about this topic? Grab a citation — every link helps keep these tools free.
RevenueLab. (2026). Preventive Maintenance vs. Downtime Cost Calculator. Retrieved from https://www.revenuelab.fyi/toolbox/preventive-maintenance-vs-downtime
<p>Source: <a href="https://www.revenuelab.fyi/toolbox/preventive-maintenance-vs-downtime" target="_blank" rel="noopener">Preventive Maintenance vs. Downtime Cost Calculator — RevenueLab</a> (2026).</p>
Source: [Preventive Maintenance vs. Downtime Cost Calculator — RevenueLab](https://www.revenuelab.fyi/toolbox/preventive-maintenance-vs-downtime) (2026).