About

Built by a maintenance practitioner

Reliability Toolbox is a set of free calculators and analysis tools for maintenance planners, reliability engineers, and the technicians who keep equipment running.

Who builds it

The site is built and maintained by a Facility Engineer and CMMS specialist with hands-on experience in maintenance planning, PM compliance tracking, work order management, and asset data across multi-building industrial sites.

The tools exist because the same calculations come up every week in real maintenance work — and most free versions online either get the formula subtly wrong, hide the useful part behind a signup, or can't take the data the way a CMMS actually exports it.

How the tools are built

Found an error?

If a formula, definition, or result looks wrong, please get in touch. Corrections from people doing the work are the best way these tools get better.

Results are estimates for planning and analysis. Always confirm against your organization's own definitions and procedures before making safety or operational decisions.