How do you calculate wrench time hours for a job list?

Divide the number of hands-on jobs by jobs completed per technician hour to get base time, then multiply by one plus the allowance. With 96 jobs at 1.8 per hour, base time is 53.33 hours; a 35% allowance brings the required time to 72 hours.

What is a good wrench time percentage?

Reactive shops run 25-35% true wrench time, well-planned proactive organizations reach 50-55%, and best-in-class can approach 60%. The 35% allowance in the example reflects a realistically high overhead burden, consistent with a plant that has not yet optimized planning and scheduling.

Why does the allowance add so much time?

Travel between the shop and equipment, waiting on parts, securing permits, hunting for tools, and coordinating with operations all consume paid hours without touching the asset. The 35% allowance turns 53.33 base hours into 72 required hours, capturing roughly a third of the schedule lost to overhead.

How is wrench time different from utilization?

Utilization measures whether a technician is on the clock and assigned to work; wrench time measures whether they are physically performing maintenance on the asset. A technician can be 100% utilized yet at low wrench time because they spend the shift traveling and waiting on parts.

How do I improve wrench time?

Kitting parts ahead of the job, pre-staging tools, batching permits, and scheduling work geographically all cut the allowance. Lowering the allowance from 35% to 20% would drop the 53.33 base hours to about 64 required hours instead of 72, freeing real crew capacity.

Can wrench time be too high?

Near-100% wrench time usually means measurement error or that planning and safety steps are being skipped. Healthy programs accept that some travel, permitting, and coordination is necessary; the goal is to minimize avoidable overhead, not eliminate all of it.

CMMS, EAM & Spare Parts Management calculator

Wrench Time Calculator

Wrench time is the share of a technician's shift spent actually turning wrenches on equipment, as opposed to traveling, waiting on parts, obtaining permits, or chasing coordination. This calculator works the practical inverse: given a set of hands-on jobs and a realistic completion rate, it estimates the total technician hours required once you pad for all the non-productive time that surrounds the work. Maintenance planners, reliability engineers, and supervisors use it to schedule crews honestly and to expose how much capacity is lost to poor planning. It matters because typical reactive maintenance organizations see only 25-35% true wrench time, meaning most paid hours never reach the equipment.

What this calculator does

Estimate productive technician wrench time after accounting for job count, work execution pace, and non-wrench delays.
a maintenance or asset-management team needs to understand technician capacity, improve planning quality, or compare productive time against paid hours for a technician work week
It divides the number of hands-on jobs by the jobs-completed-per-technician-hour rate to get base hands-on time, then multiplies by an allowance factor for travel, parts waits, permits, tooling, and coordination to estimate total required technician hours.

Formula used

Base wrench time time = planned maintenance jobs requiring hands-on work ÷ jobs completed per technician hour
Required wrench time time = base time × allowance factor

Inputs explained

Maintenance jobs requiring hands-on work:
Jobs completed per technician hour:
Travel, parts wait, permits, tools, and coordination allowance:

How to use the result

Use it when planning a maintenance day or shutdown, when sizing crews for a job list, or when quantifying how much capacity is being lost to support and coordination overhead.
It treats all jobs as the same average size and bundles every productivity loss into one allowance; a job list mixing five-minute adjustments with multi-hour rebuilds, or a site with severe parts-availability problems, will need the allowance and rate tuned per job type.

Common questions

How do you calculate wrench time hours for a job list? Divide the number of hands-on jobs by jobs completed per technician hour to get base time, then multiply by one plus the allowance. With 96 jobs at 1.8 per hour, base time is 53.33 hours; a 35% allowance brings the required time to 72 hours.
What is a good wrench time percentage? Reactive shops run 25-35% true wrench time, well-planned proactive organizations reach 50-55%, and best-in-class can approach 60%. The 35% allowance in the example reflects a realistically high overhead burden, consistent with a plant that has not yet optimized planning and scheduling.
Why does the allowance add so much time? Travel between the shop and equipment, waiting on parts, securing permits, hunting for tools, and coordinating with operations all consume paid hours without touching the asset. The 35% allowance turns 53.33 base hours into 72 required hours, capturing roughly a third of the schedule lost to overhead.
How is wrench time different from utilization? Utilization measures whether a technician is on the clock and assigned to work; wrench time measures whether they are physically performing maintenance on the asset. A technician can be 100% utilized yet at low wrench time because they spend the shift traveling and waiting on parts.
How do I improve wrench time? Kitting parts ahead of the job, pre-staging tools, batching permits, and scheduling work geographically all cut the allowance. Lowering the allowance from 35% to 20% would drop the 53.33 base hours to about 64 required hours instead of 72, freeing real crew capacity.

Last reviewed 2026-05-12.