What the directive fixes
Directive 2000/14/EC governs the noise emission of equipment intended for use outdoors. Lawnmowers, scarifiers, blowers, shredders, tillers and the small engines that drive them are all within its scope, which is why a garden shed contains more oval noise labels than the rest of a house put together.
It fixes three things.
The quantity: a sound power level, A-weighted, in decibels. Sound power is a property of the source — the total acoustic energy it radiates — and it does not depend on where you stand. That is precisely why it was chosen: a figure that depended on the listener would not be comparable between machines.
The guarantee: the marked figure is not a measured value. It is a level the manufacturer undertakes will not be exceeded, arrived at by measuring, accounting for the spread of its own production and the uncertainty of the method, and rounding. This is why the numbers on a shelf are almost all even integers.
The marking and the declaration: the level must be affixed to the machine, legibly and indelibly, and it must accompany the machine into the literature. A conformity assessment stands behind it, and for some machine types a limit applies as well as a declaration.
What it does not promise
It does not tell you how loud the machine is at your ear, on your terrace, or over your neighbour’s fence. That is a sound pressure level, it depends on distance, ground and surroundings, and it is not what is marked.
It does not tell you what your neighbours are entitled to. Local rules about the hours at which a garden machine may be run exist in most countries and are not this directive; this site does not answer questions about them.
It does not describe the character of the noise. A robot mower running at a low level for six hours and a petrol mower running at a high one for twenty minutes can be experienced in opposite ways, and nothing in a single A-weighted figure distinguishes a whine from a rumble.
And it does not measure at the operator’s position. The figure a manufacturer prints in the manual for the person holding the machine is a different quantity, obtained under a different document, and it is usually a good deal lower. Seeing the two side by side in a listing and treating them as the same number is the error this page exists to prevent.
The documents it sits next to
The method by which sound power is determined in the first place is an ISO document, and it has its own page here. The operator-position figure comes from the machine’s own product standard — the pedestrian mower standard, or the hand-held machinery family.
A petrol machine also carries an emission stage for its engine, which is about exhaust rather than sound, from an entirely separate regulation.
Which shelves it reaches here
Every powered machine family cites it: the four mower shelves, the scarifiers, the blowers, the shredders, the tillers and the robots.
Where a review here prints a noise figure, it says which of the two quantities it is. Where a listing prints a bare “dB” with no indication, the page treats it as unidentified and says so rather than assuming. On the imported end of these shelves that happens often, and assuming would put a sound pressure figure in a sound power column.
The questions that keep coming in
Is a 96 dB mower twice as loud as a 93 dB one?
Neither figure is a loudness at any listening position, so the question cannot be answered from them. Both are guaranteed sound power levels — the acoustic power the machine radiates in total — and a difference of three in that quantity is roughly a doubling of radiated power, which is not the same as a doubling of perceived loudness.
Why is the marked figure always a round number?
Because it is a guarantee, not a measurement. The manufacturer measures, adds the uncertainty of its own production and its own method, rounds up, and undertakes that no machine it sells will exceed the result. A machine measured at 94.3 is commonly marked 96.
Must the figure appear in an advertisement?
The directive requires the guaranteed level to accompany the machine, marking included, and it is why the figure turns up in catalogue listings at all. Where a listing on this shelf omits it entirely, that is worth noticing, and the review page says so.
Last reviewed 26 September 2026