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The equivalent continuous A-weighted level at the worker's ear during this task.
Use the LAeq measured for the task — with a sound level meter held near the ear, or from a dosimeter's task log — rather than a peak reading or a machine's declared emission figure, which describes the machine and not the person beside it. Tasks at a similar level can share one row. A row with no time against it is ignored.
Hours spent at this level in the day — minutes divided by 60.
The time actually spent exposed at the task's level, not the length of the shift. Twenty minutes is 0.33 hours and forty-five is 0.75. Set a row to zero to leave it out; time spent in quiet surroundings adds almost nothing and can simply be omitted.
The equivalent continuous A-weighted level at the worker's ear during this task.
Use the LAeq measured for the task — with a sound level meter held near the ear, or from a dosimeter's task log — rather than a peak reading or a machine's declared emission figure, which describes the machine and not the person beside it. Tasks at a similar level can share one row. A row with no time against it is ignored.
Hours spent at this level in the day — minutes divided by 60.
The time actually spent exposed at the task's level, not the length of the shift. Twenty minutes is 0.33 hours and forty-five is 0.75. Set a row to zero to leave it out; time spent in quiet surroundings adds almost nothing and can simply be omitted.
The equivalent continuous A-weighted level at the worker's ear during this task.
Use the LAeq measured for the task — with a sound level meter held near the ear, or from a dosimeter's task log — rather than a peak reading or a machine's declared emission figure, which describes the machine and not the person beside it. Tasks at a similar level can share one row. A row with no time against it is ignored.
Hours spent at this level in the day — minutes divided by 60.
The time actually spent exposed at the task's level, not the length of the shift. Twenty minutes is 0.33 hours and forty-five is 0.75. Set a row to zero to leave it out; time spent in quiet surroundings adds almost nothing and can simply be omitted.
The equivalent continuous A-weighted level at the worker's ear during this task.
Use the LAeq measured for the task — with a sound level meter held near the ear, or from a dosimeter's task log — rather than a peak reading or a machine's declared emission figure, which describes the machine and not the person beside it. Tasks at a similar level can share one row. A row with no time against it is ignored.
Hours spent at this level in the day — minutes divided by 60.
The time actually spent exposed at the task's level, not the length of the shift. Twenty minutes is 0.33 hours and forty-five is 0.75. Set a row to zero to leave it out; time spent in quiet surroundings adds almost nothing and can simply be omitted.
The regulation whose values the result is set beside.
The arithmetic is the same everywhere that uses a 3 dB exchange rate; only the values differ. The UK and EU name two action values and a limit value; Australia's work health and safety regulations name one exposure standard. For a US workplace the OSHA noise dose page is the right one, because OSHA uses a different exchange rate and so a different number for the same day.
Daily personal noise exposure, LEP,d
87.1 dB(A)
87.1 dB(A) is at or above the upper exposure action value of 85 dB(A), and at or above 87 dB(A), the exposure limit value — the one value judged at the ear, after any hearing protection worn. Each of these regulations requires the risk from noise to be reduced at every level, so no figure here is a finding that the noise is acceptable.
- Exposure points (HSE scale: 100 is 85 dB(A), 32 is 80 dB(A))
- 162.38 points
- Time the tasks add up to
- 7.5 hours
- Task 1's share of the day's noise energy
- 46.08 %
- Task 2's share of the day's noise energy
- 15.43 %
- Task 3's share of the day's noise energy
- 38.49 %
- Time at the loudest level, 95.0 dB(A), that reaches 85 dB(A) on its own
- 0.8 hours
They open the calculator with your figures already in it
Daily Noise Exposure (LEP,d) Calculator: 87.11 dB(A) — shown in imperial, US market. The link sets both, so the result they see is the one on your screen.
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How this was calculated
Formula source(s)
- ISO 9612:2009 and HSE L108 (Controlling noise at work): the daily personal noise exposure LEP,d = 10 log10[(1/T0) × Σ Tm × 10^(0.1 × LAeq,m)], where each task m lasts Tm hours at an equivalent continuous A-weighted level LAeq,m and T0 is the 8-hour reference day
- Control of Noise at Work Regulations 2005, regulation 4, and Directive 2003/10/EC, Article 3: lower exposure action values 80 dB(A) LEP,d and 135 dB(C) peak; upper exposure action values 85 dB(A) and 137 dB(C); exposure limit values 87 dB(A) and 140 dB(C), the limit values alone taking account of the hearing protection worn
- Work Health and Safety Regulations 2011 (Australia), regulation 56: the exposure standard for noise is an LAeq,8h of 85 dB(A) or a peak of 140 dB(C)
- HSE noise exposure points, as used in the ready-reckoner in L108: a task scores (Tm ÷ 8 hours) × 10^((LAeq,m − 85) ÷ 10) × 100 points, so 100 points is an LEP,d of 85 dB(A) and 32 points is 80 dB(A)
Inputs used
- Task 1 Noise Level, LAeq (dB(A))
- 88
- Task 1 Duration (hours)
- 3
- Task 2 Noise Level, LAeq (dB(A))
- 82
- Task 2 Duration (hours)
- 4
- Task 3 Noise Level, LAeq (dB(A))
- 95
- Task 3 Duration (hours)
- 0.5
- Task 4 Noise Level, LAeq (dB(A))
- 75
- Task 4 Duration (hours)
- 0
- Values to Compare Against
- UK and EU — 80, 85 and 87 dB(A)
- Value to Compare Against (dB(A))
- 85
Intermediate steps
- Exposure points (HSE scale: 100 is 85 dB(A), 32 is 80 dB(A))
- 162.38 points
- Time the tasks add up to
- 7.5 hours
- Task 1's share of the day's noise energy
- 46.08 %
- Task 2's share of the day's noise energy
- 15.43 %
- Task 3's share of the day's noise energy
- 38.49 %
- Time at the loudest level, 95.0 dB(A), that reaches 85 dB(A) on its own
- 0.8 hours
Confidence note: 87.1 dB(A) is at or above the upper exposure action value of 85 dB(A), and at or above 87 dB(A), the exposure limit value — the one value judged at the ear, after any hearing protection worn. Each of these regulations requires the risk from noise to be reduced at every level, so no figure here is a finding that the noise is acceptable.
What this calculation does not cover
- It combines the levels you enter and does not measure them. Each must be the task's equivalent continuous A-weighted level at the ear, not a peak or maximum reading and not a machine's declared emission, which describes the machine rather than the person beside it.
- Peak sound pressure is a separate test with its own values — 135, 137 and 140 dB(C) in the UK and EU, 140 dB(C) in Australia — and is not assessed here: a nail gun or a hammer blow can reach a peak value on a day whose LEP,d is modest.
- Hearing protection is not deducted. The action values are compared with the exposure without protection; the level under a protector is the hearing-protection page's question.
- The 8-hour reference day is how LEP,d is defined, whatever the shift length: a 12-hour shift at a steady 85 dB(A) is 86.8 dB(A), not 85.
- Where exposure varies markedly from day to day, the UK regulations allow a weekly average in place of the daily one; that is the weekly page.
Computed in your browser — nothing you enter is uploaded. Presented in US customary units and US trade terminology. Where a formula follows a published standard, that standard and its edition are cited beside it on this page; where none governs, the page says so. Local amendments override model codes — verify against the code in force where you build.
Sources checked 2026-09-21 · v1.0.0
Regulatory standards & verification citations4
- ISO 9612:2009 and HSE L108 (Controlling noise at work): the daily personal noise exposure LEP,d = 10 log10[(1/T0) × Σ Tm × 10^(0.1 × LAeq,m)], where each task m lasts Tm hours at an equivalent continuous A-weighted level LAeq,m and T0 is the 8-hour reference day
- Control of Noise at Work Regulations 2005, regulation 4, and Directive 2003/10/EC, Article 3: lower exposure action values 80 dB(A) LEP,d and 135 dB(C) peak; upper exposure action values 85 dB(A) and 137 dB(C); exposure limit values 87 dB(A) and 140 dB(C), the limit values alone taking account of the hearing protection worn
- Work Health and Safety Regulations 2011 (Australia), regulation 56: the exposure standard for noise is an LAeq,8h of 85 dB(A) or a peak of 140 dB(C)
- HSE noise exposure points, as used in the ready-reckoner in L108: a task scores (Tm ÷ 8 hours) × 10^((LAeq,m − 85) ÷ 10) × 100 points, so 100 points is an LEP,d of 85 dB(A) and 32 points is 80 dB(A)
Which documents these citations point at
Standards referenced: ISO 9612 (International Organization for Standardization, International).
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