Anchor Point Load Calculator

Example Data Table

Scenario	Weight	Workers	Fall	Decel	Config	Angle	Peak	Safety	Per-anchor (approx)
Planning check	100 kg	1	2.0 m	1.0 m	Single	—	1.30	2.0	~3.83 kN peak, ~7.66 kN design
Two-point bridle	220 lb	1	6 ft	3 ft	Two-point	90°	1.30	2.0	~1,187 lbf per anchor peak, ~2,374 lbf design
Multiple workers	90 kg	3	1.5 m	1.0 m	Two-point	60°	1.35	2.5	Higher per anchor; set simultaneity carefully

Examples are illustrative. Enter your real jobsite assumptions for planning.

Formula Used

This calculator uses a simple energy balance to estimate arrest force. The worker’s weight force is W = m·g. During arrest, the fall energy is dissipated over the deceleration distance.

F_avg = W · (1 + fall_distance / decel_distance)
F_peak = F_avg · peak_factor
F_total = F_peak · (workers · simultaneity_factor)
Single anchor: Load_anchor = F_total
Two-point bridle (symmetric): Load_per_anchor = F_total / (2·cos(angle/2)) where angle is the included angle between legs.
Design load: Design = Load · safety_factor

Reality can differ due to equipment characteristics, harness fit, slack, elasticity, and dynamics. Use this estimator for planning and discussions, not as a stamped design.

How to Use

Select your unit system, then enter worker weight and the number of workers.
Set a simultaneity factor if not all workers can load at once.
Enter free-fall distance and realistic deceleration distance for the system.
Choose single anchor or a two-point bridle configuration.
If using two points, enter the included angle between legs.
Adjust peak factor and safety factor to match your planning approach.
Click Calculate to view per-anchor and design loads above the form.
Use the download buttons to export results for records.

Anchor Loads for Fall Protection Planning

1) What this calculator estimates

This tool estimates the peak load that an anchorage may see during a fall arrest event using a simplified energy approach. It converts worker weight into force and combines fall distance with deceleration distance to approximate arrest forces for planning and documentation.

2) Key inputs and typical ranges

Most jobsite scenarios use worker weights from 70–140 kg (155–310 lb). Free-fall distance is often between 0.6–2.0 m (2–6 ft) depending on slack and connection method. Deceleration distance commonly falls around 0.9–1.2 m (3–4 ft) when energy absorbers are engaged.

3) Free-fall versus deceleration

The ratio of fall distance to deceleration distance drives force growth. If fall distance equals deceleration distance, the average arrest force is roughly 2× body-weight force. If fall distance is twice the deceleration distance, the average is roughly 3×.

4) Peak factor and dynamics

Real systems do not load perfectly smoothly. Harness stretch, line elongation, and absorber behavior can create a peak higher than the average. The peak factor lets you model that effect (for example 1.2–1.5), producing a more conservative peak estimate for comparing to component ratings.

5) Two-point bridle angle effects

When a load is shared by two legs, each anchor can see more than half the total if the included angle opens up. At 60° included angle, the multiplier is close to 1.15 per anchor. At 120°, it rises toward 2.0. Keeping the angle tighter reduces amplification and improves predictability.

6) Multiple workers and simultaneity

Shared anchors are sometimes used for access systems, temporary lifelines, or sequential work zones. The simultaneity factor helps represent realistic overlap: 1.0 assumes every worker loads at once; 0.5 assumes roughly half. Document the basis for the factor.

7) Design loads and safety margin

The design load multiplies the estimated peak by a safety factor so you can plan with margin. A factor of 2.0 is a common planning choice, while higher factors may be used when inputs are uncertain or when anchor condition, geometry, or installation quality vary across the site.

8) Practical field documentation tips

Record the connection type, fall clearance assumptions, included angle for bridles, and the selected peak and safety factors. Export the CSV or PDF for the job file, then confirm final anchorage selections using applicable standards, manufacturer guidance, and a competent engineering review.

Use results to support planning, discussions, and consistent recordkeeping.

FAQs

1) Is this a certified engineering design?

No. It is a simplified estimator for planning and documentation. Always confirm anchorage ratings, installation requirements, and governing standards with qualified safety and engineering professionals.

2) What should I enter for deceleration distance?

Use the best available stopping distance for your system, including absorber deployment and realistic stretch. If uncertain, use a conservative value (smaller distance increases force).

3) Why does the two-point option increase loads?

As the included angle opens, each leg must carry more tension to provide the same vertical support. This increases per-anchor load compared with a tight, vertical configuration.

4) What is a reasonable peak factor?

Peak factor depends on system dynamics. Many planning checks use 1.2–1.5. Use manufacturer data where available and apply a higher factor when uncertainty or shock loading is possible.

5) How do I handle multiple workers?

Enter the connected worker count and apply a simultaneity factor to reflect realistic overlap. If workers could load together, set the factor near 1.0.

6) Does the calculator include swing fall effects?

Not explicitly. Swing falls can increase hazards and change loading direction. Keep geometry conservative, reduce slack, and evaluate lateral forces and clearance using appropriate methods.

7) Can I use this for material hoisting anchors?

This version targets fall arrest planning. Hoisting and rigging have different dynamics and code requirements. Use a purpose-built lifting analysis and follow equipment and regulatory guidance.