What is machine utilization, and how do you calculate it?

You calculate machine utilization by dividing the hours a machine ran by the hours it could have run, and the denominator you choose decides what the number means. Use running plus stopped time inside your shifts to run the plant and compare machines, planned production time when the figure feeds OEE, and all calendar time when you decide whether to add a shift or buy a machine.

This guide is for plant managers and owners who want a utilization figure they can defend. It works one lathe’s week through four denominators, then shows how to roll machines and shifts up without distorting the result.

What machine utilization measures#

The IoTFlows utilization glossary entry uses measured shift time: running time over running plus stopped time, inside your shifts. That is one valid choice of several. The rest of this guide shows where each one belongs.

What counts as running#

The numerator needs a definition too. Running means the machine is in its cycle: a spindle working through a program, a press stroking, a molding machine cycling.

Use in-cycle running time as the default. Powered-on hours overstate utilization, because a machine left on through lunch counts as busy. For example, a lathe left powered on for a 16-hour day that cycled for 9 of those hours reads 100% on a power meter and 56.3% in cycle.

In-cut time answers a narrower machining question. It belongs in a spindle study, not in a plant report.

Four denominators, four different numbers#

The same running hours give four utilization figures, depending on what you divide by. None of them is wrong. Each answers a different question, so the mistake is quoting a number without its denominator.

Planned production time is the time a machine is scheduled to produce: shift time minus the time nobody intends to run it, such as breaks and maintenance windows with the machine scheduled off. Running time over planned production time is availability, the first factor of OEE, and planned vs unplanned downtime sets out which stops stay in.

Measured shift time is the running and stopped time a monitoring system recorded inside your shifts. It leaves out any stretch with no data, so a dead network link doesn’t count as a stopped machine.

Calendar time needs one more step. Vorne defines utilization as planned production time divided by all time, the factor TEEP multiplies OEE by: two 8-hour shifts, five days a week, give 80 of 168 hours, or 47.62%.^[1] That measures how much of the week you schedule.

Multiply that schedule figure by availability and you get running time over calendar time. For the same two shifts, a machine that runs 48 of its 80 planned hours runs 28.6% of the week.

Equipment standards split the term too. SEMI E10, the semiconductor industry’s specification for equipment time, defines two utilization metrics: total utilization and operational utilization.^[4]

Work one week by hand#

Take one machine and one week, then divide the same running hours four ways.

The spread runs from 28.6% to 64.9% for one machine in one week. A manager who reads 60% on one report and 29% on another is looking at the same machine through two denominators, not at two performances.

The 3.4 points between the measured and the planned figures come from two opposite moves. The planned figure removes the 6 hours of lunches and maintenance, and it keeps the 2 offline hours, because a calculation from the schedule can’t tell them from a stop.

What to count, and what to leave out#

Every hour of the week falls in one bucket. The table shows which buckets each denominator includes. Running hours are always the numerator.

Three buckets need a written rule.

• Offline time. Keep it out of a day-to-day figure. A sensor unplugged over a weekend produces 48 hours with no data, not 48 hours stopped. See how a monitoring system reports unknown time.
• Breaks. Decide once, for the whole plant. Leave breaks in when you ask where the shift went, and remove a legally required break when you compare machines or hold a team to a goal.
• Idle hours. A machine with no job inside a staffed shift is stopped, and measured shift time counts it. Whether idle hours belong in planned production time is a plant decision, and the cost of idle machines shows what those hours cost you.

Roll up shifts and machines by hours#

Add the running hours and the available hours across shifts or machines, then divide once. Averaging the percentages gives a 6-hour shift the same weight as a 10-hour one.

The 5.6-point gap is the shorter shift getting a vote it didn’t earn in hours. The same rule holds across a fleet: a cell figure built from pooled hours lets the machine with the most hours carry the most weight.

A pooled figure still hides which machine is losing the hours. Place each machine against the range for its type before you decide what to fix.

Utilization, capacity utilization and OEE#

Five metrics share the word or the inputs, and they measure different things at different scales.

The Federal Reserve computes capacity utilization for US industry as a seasonally adjusted output index divided by a capacity index.^[3] US manufacturing ran at 75.7% in August 2026, against a 1972–2025 average of 78.2%.^[2] That is an output measure across an industry, so don’t hold one machine’s running hours against it.

For example, a line that can make 10,000 units a week on its normal schedule and makes 7,800 runs at 78.0% capacity utilization. If it ran 100 of its 120 scheduled hours, its time-based utilization is 83.3%. The rest of the loss is in the rate the line ran at.

Utilization inside your shifts, with breaks removed, is the availability factor of OEE. OEE also multiplies in performance and quality, so a machine can post 90% utilization while running at half its ideal speed.

TEEP goes the other way and adds the calendar. In Vorne’s example, a 65% OEE on two shifts, five days, gives a TEEP of 30.95%.^[1] The guide to utilization, uptime, OEE and TEEP works one week through all of them, OOE included.

What is a good machine utilization rate?#

No single rate fits every machine. Mike Lynch, writing in Modern Machine Shop, describes shops that can justify almost any effort to pass 95% spindle run time and others satisfied below 20%, and advises improving the machines that cause bottlenecks.^[5]

A machine that isn’t the constraint can sit idle for long stretches and still be used correctly.^[5] For example, a deburring station that keeps up with three mills at 35% utilization needs no improvement project. A low figure there is information about the schedule.

How much of the cycle an operator carries sets the ceiling. For example, the IoTFlows CNC machine guide expects 40–60% uptime inside shifts on a manual, operator-intensive CNC and 75–85% on a fully automatic one. The utilization ranges by machine type cover presses, molding machines and lights-out cells.

Use those ranges for planning only. Set the first goal from your own baseline:

1. Measure a full quarter

   Collect running and stopped time on every machine for one complete quarter, with the same denominator throughout.

2. Read each machine’s figure

   Use the per-machine result as that machine’s baseline, not the plant average.

3. Set the goal a few points above

   A machine at 48% gets a goal of 55%, not 85%. A goal the machine has never met teaches operators to ignore the number.

4. Hold it for a quarter

   Leave the goal alone for a quarter, then raise it when the machine gets there. The goal-setting guide walks through it.

Measure utilization from the machine#

IoTFlows puts a sensor on each machine that decides running or stopped every second from vibration and sound, with no PLC connection. Utilization is measured inside your shifts: running time over running plus stopped, with offline time reported separately as unknown and kept out of both.

Set your shifts and time zone first, because they bucket every number as it arrives. The Advanced Report then shows any period by machine, and its Exclude None switch removes stops of severity None, such as a mandated lunch, from both terms. See what the number includes.

Storm Power Components doubled machine utilization with SenseAi on its CNC machines, lasers and presses, and now schedules on real utilization data. Read the Storm Power story. See how the sensor, shifts and reports fit together on machine utilization tracking.

Before you report a utilization figure#

Run this list against any utilization number before it goes on a wall, into a meeting or into a capacity plan.

• Name the denominator beside the figure: “61.5% of measured shift time”, not “61.5%”.
• Match it to the decision: measured shift time to run the plant, planned production time for OEE, calendar time for a shift or machine purchase.
• Count in-cycle time as running, not powered-on time.
• Keep offline hours out, and fix the connection that caused them.
• Fix the rule for breaks and idle hours once, plant-wide, and note it on the report.
• Pool hours across shifts and machines, never average percentages.
• Set goals from each machine’s last full quarter, then read the machines one by one.