How do you calculate required vacuum pump capacity?

Multiply the per-cup leak rate (SCFM) by the number of cups, then by an evacuation factor for cycle speed and a porosity safety factor. With 0.6 SCFM per cup across 6 cups and 1.5x factors for both speed and porosity, the calculator returns 8.1 CFM required.

What size vacuum pump do I need for my gripper?

Pick a pump whose flow at your working vacuum level meets or exceeds the required CFM this calculator gives. For the default case that means a source delivering at least 8.1 CFM at the target inHg; size up if the part is porous or the cycle is very short.

Why does cycle speed affect vacuum flow requirements?

A faster cycle gives the pump less time to evacuate the cup volume before the lift, so you need extra flow to reach grip vacuum in time. The evacuation factor (1.5x by default) inflates the leak-based flow to cover that transient, on top of steady-state leakage.

How do I account for porous parts like cardboard?

Porous material leaks continuously through its surface, so add a porosity safety factor above 1.0. The default 1.5x roughly covers moderately porous stock; heavily perforated or corrugated material can need 2x or more and is often better handled with a high-flow blower than a venturi.

CFM vs inHg — which matters for sizing a vacuum source?

Both. inHg sets how hard you clamp; CFM sets whether you can reach and hold that vacuum against leakage and short cycles. This calculator sizes CFM; use the vacuum cup holding force tool to set the inHg you need, then confirm the source delivers your CFM at that inHg.

What is per-cup leak rate and where do I get it?

It is the airflow a single cup passes at working vacuum, driven by seal and surface leakage, published in cup or generator data sheets as SCFM. The default 0.6 SCFM is a typical mid-size cup on a real surface; smooth glass leaks less, textured plastic more.

Robotics & Automation calculator

Vacuum Pump Capacity Calculator

Vacuum pump capacity is the airflow, in CFM, your vacuum source must move to establish and hold grip across all cups on an end-of-arm tool. Automation engineers and pneumatics specifiers use it to pick a pump, venturi generator, or blower that will not starve the gripper mid-cycle. It matters because an undersized source cannot pull vacuum fast enough to grab on a short cycle, or cannot keep up with leakage on porous parts, so the robot fumbles picks. Sizing on flow (CFM) rather than only vacuum level (inHg) is what separates a workcell that runs reliably at rate from one that drops parts when the line speeds up.

What this calculator does

Estimate required vacuum pump capacity in CFM from per-cup leak rate, cup count, evacuation time factor, and a safety factor for porous materials.
Use it when sizing a vacuum pump or generator for an EOAT so the pump pulls the cells fast enough through transfer, peel, and porous loads.
It multiplies per-cup leak rate by cup count and by evacuation and porosity factors to estimate the CFM a vacuum source must deliver at the target vacuum level.

Formula used

Required vacuum CFM = per-cup leak rate x number of cups x evacuation factor x porosity safety factor
Confirm against pump or generator data sheet at the target vacuum level.

Inputs explained

Per-cup leak rate:
Number of cups:
Evacuation factor for cycle speed:
Porosity safety factor:

How to use the result

Use it when selecting a vacuum pump or generator for a new gripper, or when an existing cell loses grip on fast cycles or on leaky, porous material.
Pump and generator data sheets rate flow at a specific vacuum level; a source that hits your CFM at low vacuum may fall short at your working inHg, so always confirm against the curve, not the headline number.

Current U.S. benchmarks

Global copper trades at $13,484 per tonne (IMF via FRED, May 2026), up 41.5% in a year, and U.S. industrial electricity averages 8.66 cents per kWh. Both feed electrified-hardware unit economics.

Common questions

How do you calculate required vacuum pump capacity? Multiply the per-cup leak rate (SCFM) by the number of cups, then by an evacuation factor for cycle speed and a porosity safety factor. With 0.6 SCFM per cup across 6 cups and 1.5x factors for both speed and porosity, the calculator returns 8.1 CFM required.
What size vacuum pump do I need for my gripper? Pick a pump whose flow at your working vacuum level meets or exceeds the required CFM this calculator gives. For the default case that means a source delivering at least 8.1 CFM at the target inHg; size up if the part is porous or the cycle is very short.
Why does cycle speed affect vacuum flow requirements? A faster cycle gives the pump less time to evacuate the cup volume before the lift, so you need extra flow to reach grip vacuum in time. The evacuation factor (1.5x by default) inflates the leak-based flow to cover that transient, on top of steady-state leakage.
How do I account for porous parts like cardboard? Porous material leaks continuously through its surface, so add a porosity safety factor above 1.0. The default 1.5x roughly covers moderately porous stock; heavily perforated or corrugated material can need 2x or more and is often better handled with a high-flow blower than a venturi.
CFM vs inHg — which matters for sizing a vacuum source? Both. inHg sets how hard you clamp; CFM sets whether you can reach and hold that vacuum against leakage and short cycles. This calculator sizes CFM; use the vacuum cup holding force tool to set the inHg you need, then confirm the source delivers your CFM at that inHg.

Last reviewed 2026-05-12.