HAV Exposure Calculator
Use this calculator to work out a worker's daily exposure to hand-arm vibration from one or more tools, and see how it compares with the legal exposure action value and limit value.
Prepared by Morgan Compliance Group · Published 23 October 2026 · Updated 23 October 2026
Who it's for
Employers, supervisors and anyone managing the use of power tools and other vibrating equipment.
Calculate daily hand-arm vibration exposure
Add up to ten tools and enter the vibration magnitude and daily trigger time for each. Partial exposure is calculated as A(8) = a × √(T / 8), with a in m/s² and T in hours. Points for each tool are 2 × a² × T. Total daily A(8) is calculated from the combined squared partial exposures. No entries are sent to a server.
Tools used during a working day
Enter the representative vibration magnitude for each tool and the time it is actually vibrating. Use the same worker's exposure for one working day. Times to the action and limit values shown for individual tools assume no other vibrating equipment is used.
| Tool name | Vibration (m/s²) | Hours | Minutes | Partial A(8) | Points | Time to EAV | Time to ELV | Remove tool |
|---|---|---|---|---|---|---|---|---|
| Enter values | Enter values | Enter values | Enter values |
Total daily vibration exposure
Daily A(8)
0.00 m/s²
Total exposure points
0
Enter a tool vibration magnitude and trigger time to calculate the daily exposure.
Exposure action value: 2.5 m/s² A(8), 100 points. Exposure limit value: 5.0 m/s² A(8), 400 points. Calculations use unrounded values when comparing thresholds.
Where to find vibration values
Use the manufacturer's declared vibration value with care, as real-use levels can be higher. Better still, use reliable measurements or HSE's published tool data. A realistic value matters more than the calculation itself.
Trigger time, not shift length
Only count the time the tool is actually vibrating in the worker's hands. Workers often overestimate this, so observe the task and check the likely daily trigger time.
What the law requires
The Control of Vibration at Work Regulations 2005 set a daily exposure action value of 2.5 m/s² A(8), or 100 points, and a daily exposure limit value of 5.0 m/s² A(8), or 400 points. At or above the action value, employers must take steps to reduce exposure and provide appropriate health surveillance. Exposure must not exceed the limit value.
Reducing exposure
Choose lower-vibration tools and methods, maintain tools properly, limit trigger time, rotate tasks where this reduces individual exposure and train workers to report symptoms such as tingling, numbness or whitening of the fingers.
This calculator gives an estimate based on the values you enter. It does not replace a vibration risk assessment.
Sources: HSE hand-arm vibration guidance; HSE exposure calculator guidance.
This resource is general guidance. Adapt it to your own business, activities and risks.
Need help managing vibration risk?
We can assess your tools and tasks, set realistic exposure limits and set up health surveillance arrangements.
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