How do I calculate Safety Guard Distance (ISO 13857)?

To calculate Safety Guard Distance (ISO 13857): Enter Guard opening size, Body part reaching through, Reach direction and other values. Click Calculate. INDUGRID computes the result instantly using the formula: Ds = K × (T_s + T_r + T_c) for presence-sensing devices (ISO 13855). No registration required.

What units does the Safety Guard Distance (ISO 13857) calculator use?

The Safety Guard Distance (ISO 13857) calculator uses the following units: mm. SI units are used by default.

Is the Safety Guard Distance (ISO 13857) calculator free?

Yes. The INDUGRID Safety Guard Distance (ISO 13857) calculator is completely free, requires no account or login, and works on desktop and mobile browsers.

Machine Safety

Safety Guard Distance (ISO 13857)

Calculate the minimum safe distance between a danger zone and a protective structure (fixed guard, fence, barrier) to prevent reaching the hazard.

Units:

in LinkedIn

💡Safe distances per ISO 13857 are minimum values — always round UP to the next 50mm or 100mm. The calculated distance assumes no tools or objects can be inserted to bypass the guard. Consider upper and lower limb reach separately for complex guard designs.

Ds = K × (T_s + T_r + T_c) for presence-sensing devices (ISO 13855)

Input

Guard opening size iSize of the largest opening in the guard structure in mm. Smaller openings require greater distance.

Body part reaching through iWhich body part can reach through or over the guard, depending on opening size.

Reach direction iReaching through an opening or over the top of a guard.

Guard height (if over guard) iHeight of the top of the guard above the floor/platform in mm. Only relevant when reaching over.

Result

Minimum safe distance [mm] —

Recommended design distance [mm] —

Standard reference —

Design notes —