Hand-arm vibration calculator: A(8) and exposure points

An online tool for working out daily hand-arm vibration exposure (HAV). Enter each tool's vibration magnitude and trigger time: the calculator adds the partial exposures into A(8) and HSE exposure points, shows how many minutes are left before the action and limit values, and prints a record for the file.

How to use it

Choose the norm

Your country's values are preselected; switch them if the site works to other rules.

Add tools and trigger time

Pick a tool from the HSE list or enter your own value, then the time hands were on the running tool.

Read the time left and save

The verdict and minutes left appear at once; the PDF button gives a record for the file.

Add up a shift of vibrating tools and see how long is left today

Norm

Source: Control of Vibration at Work Regulations 2005; HSE

Control of Vibration at Work Regulations 2005: 100 points is the exposure action value, 400 is the exposure limit value. Above the action value — a program of controls and health surveillance.

Daily exposure A(8)

3.15 m/s²

158 points · trigger time 1 h 15 min

2.5

Above the exposure action value of 2.5 m/s² A(8), below the limit value of 5 m/s²Measures are needed: cut trigger time, choose lower-vibration tools and accessories, rotate tasks, train workers and arrange health checks.

Manufacturer's declared values

Multiply declared values by Use at least 2.5 m/s² when less is declared (Safe Work Australia)

Applies only to rows marked "Value from the manufacturer's manual". Declared values come from laboratory tests and can be well below real use on site; the 2006 edition of CEN/TR 15350 suggested ×1.5–2 for electric tools. A measurement on the same job is better than any multiplier.

For the record (PDF and printout)

Worker Task Site Date Assessed by

These fields appear only in the PDF and on the printout.

Tools in the shift

trigger time — hands on a running tool

Tool name

Vibration a_hv, m/s²

h min

Value from the manufacturer's manual

HSE in use: 7–13 m/s², initial value 11 m/s²

Tool name

Vibration a_hv, m/s²

h min

Value from the manufacturer's manual

HSE in use: 3–10 m/s², initial value 7 m/s²

Add a tool

Points table (like the HSE ready-reckoner)

Exposure points for a vibration magnitude and daily trigger time: green — below 100 (action value), amber — 100 to 400, red — above 400 (limit value).

a_hv, m/s²	15 min	30 min	1 h	2 h	3 h	4 h	6 h	8 h
2.5	3	6	13	25	38	50	75	100
3	5	9	18	36	54	72	108	144
3.5	6	12	25	49	74	98	147	196
4	8	16	32	64	96	128	192	256
5	13	25	50	100	150	200	300	400
6	18	36	72	144	216	288	432	576
7	25	49	98	196	294	392	588	784
8	32	64	128	256	384	512	768	1,024
10	50	100	200	400	600	800	1,200	1,600
12	72	144	288	576	864	1,152	1,728	2,304
15	113	225	450	900	1,350	1,800	2,700	3,600
20	200	400	800	1,600	2,400	3,200	4,800	6,400

Typical vibration of 40 tools (HSE)

In-use ranges measured by HSE and its recommended initial value for a first assessment. Source: HSE

Tool	Range, m/s²	Initial value, m/s²
Drills
Drill, standard bit	2–5	5
Drill with a hole saw	4–12	10
Core drill, 78–107 mm	6–8	8
Hammer drill, 5–8 mm masonry bit	7–13	11
Rock drill	10–28	26
Breakers and hammers
Breaker (jackhammer)	7–18	14
Demolition or rotary hammer	10–21	18
Pneumatic hammer	10–29	25
Chipping hammer, welds	20–32	31
Chipping hammer, stone, concrete, rust	11–22	20
Stone hammer	7–22	18
Needle scaler	12–26	19
Needle scaler, vibration-reduced	3–8	7
Scabbler	4–14	12
Grinders, sanders, polishers
Angle grinder, 100–180 mm	3–10	7
Angle grinder, 100–125 mm flap disc	2–5	4
Angle grinder, 220–300 mm	4–11	9
Die grinder	5–10	8
Straight grinder	4–9	8
Pedestal grinder (holding the workpiece)	2–11	8
Angle polisher, mop or soft pad	1–3	3
Random-orbital sander	6–14	12
Orbital sander	4–12	9
Saws and cutters
Cut-off saw, masonry	5–14	13
Reciprocating saw	7–27	18
Jigsaw	9–17	11
Nibbler	7–12	12
Router	2–3	3
Compactors, wrenches and other site tools
Plate compactor	9–22	18
Plate compactor, vibration-reduced	2–7	4
Impact wrench, 3/8–3/4 in drive	3–6	5
Impact wrench, 1 in drive	7–11	10
Stapler	2–6	4
Water jetting gun	1–5	4
Garden and forestry
Chainsaw	3–7	7
Brushcutter, saw head	3–5	5
String trimmer	2–7	7
Hedge trimmer	3–14	7
Mower, hand-guided	3–8	6
Ride-on mower	3–6	5

An estimate for a competent person to review, not a measurement with a vibration meter and not an expert opinion. The result is only as good as the vibration magnitude and trigger time you enter: real vibration depends on the tool's condition, the accessory, the material and the operator's grip.

Features

Several tools in one shift

Partial exposures add up as the root of summed squares, the way ISO 5349-1 and HSE do it; each tool shows its points per hour and its share of the day.

Time left, not just a verdict

For every tool: how many more minutes it can run today before 2.5 and 5 m/s² A(8), counting everything already used in the shift.

The norms of your country

EU directive, UK regulations with HSE points, Safe Work Australia, ANSI S2.70, Brazil's NR-09, Russia's SanPiN with levels in dB and Indonesia's Permenaker table.

HSE values for 40 tools

Breakers, drills, grinders, compactors, chainsaws: the in-use range HSE measured and its recommended initial value — a starting point when you have no measurement.

Trigger time by count

Drilling 120 holes at 30 seconds each? Enter operations × seconds instead of guessing hours — the approach HSE recommends for repetitive work.

A record for the file

PDF or printout with the worker, task, site, norm, tools and totals and signature lines; a copied link reopens the same calculation.

What you can do

Work out daily vibration exposure A(8) for several tools
Count HSE exposure points against 100 and 400
Find out how many minutes a tool can still be used today
Correct manufacturer's declared values for real use
Check against the norms of the EU, UK, Australia, USA, Brazil, Russia or Indonesia
Download a PDF record with signature lines

Why trigger time decides more than the length of the shift

Exposure grows with the square of the vibration magnitude and only in proportion to time. A tool at 5 m/s² reaches the action value in two hours; one at 10 m/s² — in thirty minutes, because doubling the vibration multiplies the points by four. Only the time the hands are on a running tool counts, and it is usually far shorter than the time on the job: HSE notes that workers are unlikely to report it accurately and suggests timing a sample — half an hour, or a few holes — and scaling it to the shift. That is why the calculator accepts operations × seconds as well as hours and minutes.

Frequently asked questions

How are HAV exposure points calculated?

Points = 2 × a² × hours, where a is the vibration magnitude in m/s² and hours is the trigger time. This is HSE's scale for the same A(8): 100 points equal the exposure action value of 2.5 m/s² A(8) and 400 points the limit value of 5 m/s². A tool at 7 m/s² gives about 100 points per hour, at 10 m/s² — 200. Points from different tools simply add up, which is why they are handy on site.

Can I use the vibration value from the tool's manual?

As a start, yes, but check it. Declared values come from laboratory test codes, and HSE warns that some of them underestimate workplace vibration substantially. Safe Work Australia advises using 2.5 m/s² whenever less is declared, and the 2006 edition of CEN/TR 15350 suggested multiplying electric tool values by 1.5–2. Tick "Value from the manufacturer's manual" in the row, and the correction chosen under "Manufacturer's declared values" is applied to that row only.

What exactly is trigger time and how do I measure it?

It is the time the hands are actually in contact with the tool while it is running — not the time on the job. HSE suggests observing the work for about half an hour and scaling it to the shift, or timing a few repeated operations and multiplying by how many are done in a day. For the second way, switch the row to "Operations × seconds".

Why is the Russian limit 2.0 m/s² and not 5?

SanPiN 1.2.3685-21, table 5.4, sets 2.0 m/s² (126 dB) as the equivalent corrected vibration acceleration over a shift for EACH axis Xl, Yl and Zl, with no separate action value. The a_hv of a tool manual is the vector sum of all three axes, so comparing it with 2.0 gives an estimate with a margin. The level in dB is counted from 10⁻⁶ m/s², as in the SanPiN.

How does the Indonesian table work for several tools?

Permenaker 5/2018 sets the threshold (NAB) by total daily exposure time: 5 m/s² for 6–8 hours, 6 for 4–6, 7 for 2–4, 10 for 1–2, 14 for half an hour to an hour and 20 m/s² for under half an hour. For several tools the calculator takes the energy-equivalent magnitude over their total time and compares it with the NAB for that time.

Is there a legal limit for hand-arm vibration in the USA?

OSHA has no specific standard for it. The values offered here come from the voluntary ANSI S2.70-2006 standard: a daily exposure action value of 2.5 m/s² A(8) and a limit value of 5.0 m/s², taken from the EU directive. The calculator labels them as voluntary.

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Who is this tool for?

🦺 Safety officers and site supervisors

Published 21 Oct 2026 Author: The Supreme