Free Noise Exposure Calculator
How to use the noise exposure calculator
To calculate daily noise exposure, enter the activities that make up one employee’s working day:
Enter the task or process, such as cutting, grinding, assembly or general workshop duties.
Add the measured noise level, expressed as LAeq in dB(A).
Enter the actual exposure duration in hours and minutes.
Add further tasks, including relevant quieter periods, without counting the same time twice.
Review the results, including daily personal noise exposure, exposure points and each task’s contribution.
If you have measured LCpeak values, enter these to check peak noise separately. You can export your results as a CSV file or create a printable summary.
Use representative noise measurements and realistic exposure durations. The calculator processes the information you enter; it does not measure sound.
What is daily personal noise exposure?
Daily personal noise exposure, written as LEP,d, combines the noise levels and durations experienced throughout a working day into a value referenced to eight hours.
This allows exposure from different tasks and shift lengths to be compared consistently. An eight-hour reference does not mean the employee must work an eight-hour shift.
Decibels use a logarithmic scale, so noise levels cannot be combined using an ordinary arithmetic average. A relatively short, noisy task can contribute more exposure than several hours of quieter work.
Example: calculating exposure across a working day
| Task | Measured LAeq | Exposure duration |
|---|---|---|
| Grinding | 94 dB(A) | 1 hour |
| Assembly | 82 dB(A) | 5 hours |
| Quieter work | 75 dB(A) | 2 hours |
These example activities produce a combined LEP,d of approximately 86.2 dB(A) and 133.1 exposure points. The one-hour grinding task contributes the largest share of the daily exposure.
Understanding noise exposure action values
The Control of Noise at Work Regulations 2005 set the following values for workplaces in Great Britain:
| Exposure value | Daily or weekly exposure | Peak sound pressure |
|---|---|---|
| Lower exposure action value | 80 dB(A) | 135 dB(C) |
| Upper exposure action value | 85 dB(A) | 137 dB(C) |
| Exposure limit value | 87 dB(A) | 140 dB(C) |
Action values are assessed without deducting hearing protection. The exposure limit values take account of the protection provided.
This calculator shows unprotected exposure. A result above 87 dB(A) therefore requires further assessment of controls and hearing protection; it does not, by itself, establish whether the legal limit has been exceeded. See HSE’s guidance on noise exposure values.
Noise exposure calculator FAQs
What do noise exposure points mean?
Exposure points show how individual tasks contribute to the total. 100 daily points corresponds to 85 dB(A) LEP,d, while approximately 32 points corresponds to 80 dB(A). Points from separate exposure periods can be added together. See HSE’s daily noise exposure ready-reckoner.
Can I calculate weekly noise exposure?
Yes. Select weekly exposure and enter the LEP,d for each exposed day. The calculation uses a five-day reference, even where the working week contains a different number of days.
Weekly averaging is only appropriate where daily exposure varies markedly and the relevant regulatory conditions are met. Peak noise must still be considered separately. Further information is available through HSE’s exposure calculators.
Is this the HSE noise calculator?
This is SNR Noise Consultants’ independently developed calculator. It uses logarithmic exposure calculations and the exposure-points approach described in HSE guidance. It is not an HSE product or an HSE-endorsed tool.
Does the calculator replace a Noise at Work assessment?
No. A calculation is one part of an assessment. Employers also need to consider the reliability of measurements, peak noise, exposure variability, noise controls, hearing protection and other relevant risks.
Need help assessing workplace noise?
SNR Noise Consultants provides Noise at Work assessments across the UK, helping businesses understand employee exposure and identify practical ways to reduce noise risks.
Based in Scarborough, we support employers with workplace noise measurements, personal dosimetry, hearing protection assessments and clear recommendations.
If you need reliable measurements for the calculator or help interpreting your results, request a Noise at Work assessment.