Does a robot mounted on a shelf or ceiling need less reach?

Ceiling mounting moves the robot base above the work surface, so the arm reaches down rather than across. This changes the geometry: a ceiling-mounted arm can cover a larger floor area but may need a longer reach to get to the table surface directly below. Always calculate the 3D distance from the mounting point to the farthest task point.

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Robot Reach Calculator

Q: How do I calculate the robot reach I need?

Measure the horizontal distance from the robot base center to the farthest pick or place point. If the work surface is at a different height than the robot base, measure that vertical difference too. Required reach = sqrt(horizontal² + vertical²). Apply a 1.2× safety margin minimum so you are not operating the arm at its extreme extension.

Q: What is the reach of a typical cobot?

Most cobots have a reach of 700 to 1,300 mm. The UR3e covers 500 mm, the UR5e 850 mm, and the UR10e 1,300 mm. FANUC CRX-10iA reaches 1,249 mm. If your task geometry requires more than 1,500 mm reach, a standard articulated arm is usually needed.

Q: What is the longest-reach robot in the database?

The ABB IRB 8700 has the longest rated reach in the Industrial Robotics Hub database at 4,200 mm — suited for automotive body panels and large press stations. The FANUC M-2000iA/1700L reaches 3,734 mm at 1,700 kg payload.

Measure the horizontal distance from the robot base to the farthest pick or place point. Add the height difference if the work surface is above or below the mounting plane. The calculator gives you the minimum arm reach and links to robots in that class.

Your cell geometry

Horizontal distance (mm)

From robot base centre to the farthest pick or place point, measured horizontally

Height difference (mm) — positive = above mounting plane, negative = below

Work surface 200 mm above base → enter 200. Conveyor 300 mm below base → enter −300. Same height → enter 0.

Safety margin

Never run the arm at 100% reach — speed, payload, and repeatability all drop at full extension. 1.2× is the standard minimum.

1.2× Standard minimum 1.3× Path variation 1.5× New installation

Geometric reach

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√(h² + v²)

Minimum rated reach

—

with safety margin

Robot class

—

Geometry

Reach class scale

≤ 500 mm

Micro arm

500–900 mm

Compact cobot / SCARA

900–1350 mm

Standard cobot

1350–1800 mm

Long-reach cobot / small articulated

1800–2500 mm

Standard articulated

2500–3500 mm

Large articulated

3500 mm+

Super-long / ultra-heavy

Work at 70–80% of rated reach

At full arm extension, speed, payload, and repeatability all degrade. Manufacturers recommend keeping your task envelope within 70 to 80% of rated reach. The 1.2× margin in the calculator gives you a 17% buffer above your geometric need — which maps to roughly 80% of arm usage. If your cell layout is still being designed, add 1.3× to allow for future fixture adjustments.

Next steps

Payload sizing tool Size payload before reach Cycle time tool Check format vs throughput All robots 263 models, all specs

Frequently asked questions

How do I calculate the robot reach I need? +

Measure the horizontal distance from the robot base centre to the farthest pick or place point. If the work surface is at a different height, measure that vertical difference too. Required reach = √(horizontal² + vertical²). Apply a 1.2× safety margin so you are not running the arm at its extreme extension.

Why should I not spec a robot to its maximum reach? +

At full extension, robot arms lose speed, payload capacity, and repeatability. Most manufacturers recommend operating at 70 to 80% of rated reach for best performance. A longer arm running at 75% extension outperforms a shorter arm running at 100%.

Does ceiling mounting change the reach I need? +

Yes. Ceiling mounting shifts the robot base above the work surface, so the arm reaches down. You still need to calculate the 3D distance from the mounting point to the farthest task point. The height difference becomes positive and larger, increasing the geometric reach needed compared to a floor-mounted robot at work-surface height.

What is the reach of a typical cobot? +

Most cobots reach 700 to 1,300 mm. UR3e: 500 mm, UR5e: 850 mm, UR10e: 1,300 mm, FANUC CRX-10iA: 1,249 mm. If your task geometry exceeds 1,500 mm reach, a standard articulated arm is usually the right class.

What is the longest-reach robot in the database? +

The ABB IRB 8700 reaches 4,200 mm — suited for large automotive press stations. The FANUC M-2000iA/1700L reaches 3,734 mm at 1,700 kg payload. Both are floor-mounted arms for super-heavy applications.