Free tool for UK builders
Daily noise exposure calculator
Work out one person’s daily noise exposure (LEP,d) from the noisy activities in their working day. You get the result in dB(A) and in HSE’s exposure points, checked against the lower and upper exposure action values. It uses the formula in the Control of Noise at Work Regulations 2005.
Work out a day’s noise exposure
Add each noisy activity in one person’s working day, with the noise level they are exposed to (LAeq, in dB(A)) and how long it lasts. Everything is worked out in your browser. Nothing you enter is sent to us.
Enter a noise level and a time for at least one activity.
Lower exposure action value: 80 dB(A). Upper exposure action value: 85 dB(A). Both are compared with the exposure without hearing protection. Exposure limit value: 87 dB(A), at the ear, taking hearing protection into account.
This is a guide. Your risk assessment decides the controls.
The calculator only does the arithmetic. The result is only as good as the figures you enter, so use it alongside your risk assessment, not instead of it.
How the calculation works
The calculator uses the formula in Schedule 1 to the Control of Noise at Work Regulations 2005, and the exposure points system in Appendix 3 of HSE’s guidance L108. In each formula, L is an activity’s noise level in dB(A) and T is how long it lasts, in hours.
Daily exposure
LEP,d = 10 × log10[(1 ÷ 8) × Σ(T × 10^(L ÷ 10))]
Exposure points for an activity
points = 100 × (T ÷ 8) × 10^((L − 85) ÷ 10)
Daily exposure from total points
LEP,d = 85 + 10 × log10(points ÷ 100)
85 dB(A) is 100 points and 80 dB(A) is 32 points. Points add up across activities.
HSE’s worked example: 5 hours at 80 dB(A), 2 hours at 86 dB(A) and 45 minutes at 95 dB(A). HSE’s calculator gives 145 points and a daily exposure of 87 dB(A), which is above the upper exposure action value. This calculator gives the same 145 points and 86.6 dB(A), which HSE’s calculator shows rounded to 87. HSE says the priority for noise control is the 45 minutes at 95 dB(A), because it gives the most exposure points (L108, Box 4). Press Use HSE’s worked example to load it.
What the action and limit values mean
The Control of Noise at Work Regulations 2005 set a lower exposure action value of 80 dB(A), an upper exposure action value of 85 dB(A) and an exposure limit value of 87 dB(A), as a daily or weekly personal noise exposure (regulation 4).
At or above the lower exposure action value, the employer must assess the risk (regulation 5) and make hearing protectors available on request (regulation 7(1)).
At or above the upper exposure action value, the employer must reduce exposure to as low a level as is reasonably practicable with a programme of organisational and technical measures, not counting hearing protectors (regulation 6(2)). If they cannot get exposure below the upper exposure action value by other means, they must provide hearing protectors (regulation 7(2)).
The action values are compared with the exposure without hearing protection. The exposure limit value takes account of the protection given by the hearing protectors provided (regulation 4(5)). HSE’s guidance says an employee must not be exposed above the limit values at the ear (L108, paragraph 73).
What this calculator does and does not account for
- It works out the daily exposure without hearing protection. That is the figure to compare with the action values.
- It does not account for hearing protection, so it cannot tell you whether the exposure limit value is met. HSE has a separate calculator that estimates the performance of hearing protection.
- It does not assess peak sound pressure. The Regulations also set peak sound pressure values of 135, 137 and 140 dB (C-weighted).
- It works out daily exposure only. Where exposure varies markedly from day to day, the Regulations let an employer use weekly exposure instead (regulation 4(4)). HSE’s weekly ready-reckoner and calculator cover that.
- It does not measure noise. Enter the level that represents what the person is exposed to during each activity.
Put the controls in your paperwork
Write the noise controls into your RAMS
Describe the job in plain English and The Site Book prepares a site-specific RAMS draft for your competent review. Your first project is free.
Start free →Brief the crew with a free toolbox talk
The free Noise at Work toolbox talk has key points, do’s and don’ts, and questions to check understanding. In The Site Book, delivering toolbox talks and collecting signatures is on Pro and above.
Read the toolbox talk →Related
More free tools: all free tools and templates.
Sources
- The Control of Noise at Work Regulations 2005, regulation 4 (exposure limit values and action values) — legislation.gov.uk · Accessed 27 October 2026
- The Control of Noise at Work Regulations 2005, regulation 5 (assessment of the risk) — legislation.gov.uk · Accessed 27 October 2026
- The Control of Noise at Work Regulations 2005, regulation 6 (elimination or control of exposure) — legislation.gov.uk · Accessed 27 October 2026
- The Control of Noise at Work Regulations 2005, regulation 7 (hearing protection) — legislation.gov.uk · Accessed 27 October 2026
- The Control of Noise at Work Regulations 2005, Schedule 1 (daily personal noise exposure) — legislation.gov.uk · Accessed 27 October 2026
- Controlling noise at work: Guidance on Regulations (L108, third edition, 2021), Appendix 3 — Health and Safety Executive · Accessed 27 October 2026
- Noise exposure calculators and ready-reckoners — Health and Safety Executive · Accessed 27 October 2026