Two ways of declaring the same noise
Sound power in bels is common ground.
Apple and Dell print the mean, LWA,m, while HP and Lenovo print a statistical upper limit, LWA,c or LWAd. On Apple and Dell sheets the mean sits in one column and KV, the statistical adder, in the next; HP and Lenovo print a single upper limit with the adder inside it. A Lenovo 2.5 is therefore not 0.3 bels louder than a Dell 2.2. They are different kinds of number.
Apple's footnote spells out the relationship: KV is the adder for computing the upper limit from the mean. Apple and Dell are ranked against each other here, HP and Lenovo against each other, and every laptop figure carries its convention.
New to bels and KV? Our sound power and sound pressure primer starts from the basics.
MacBooks declare the same with or without a fan
Every current MacBook comes in at 1.2 or 1.3 bels at idle and on Apple's wireless web test, with 3 or 4 dB at the operator position.
The MacBook Neo and MacBook Air are fanless, by Apple's statements, so their figures are the measurement floor. The MacBook Pro 14 with M5 has a fan and declares the same 1.3 bels, which means the fan adds nothing measurable at light loads. How loud a MacBook Pro gets under a long render is a separate question, and Apple leaves it unanswered, because its declaration has no full load mode. Apple declares its desktops the same way. In our desktop PC guide the Mac Studio has the lowest idle figure.
What is the quietest Windows laptop?
It depends on the convention. On the mean, Dell's 14 Plus leads at 2.2 bels and 14.1 dB; on the upper limit, HP's EliteBook X G2i 14 leads at 2.2 bels and 14 dB.
The Dell declares the same figures under disk access as at idle. Dell's premium machines do not beat it: the Pro 14 Premium declares the same 2.2 bels with 22.0 dB of sound pressure, and the XPS 13 comes in at 2.5 bels.
HP's EliteBook is the lowest Windows figure on its scale, though its configured price on HP's store runs past $6,000.
Lenovo's ThinkPads declare 2.5 to 2.8 bels at idle. Lenovo alone publishes a processor load figure, and the T14s Gen 7 holds 26.7 dB with the CPU working.
On a budget the paperwork still exists: our guide to the quietest laptops under $1,000 found five models under that price with declared noise, including the fanless MacBook Neo and a $629.99 Dell 15 that declares the same idle sound power as the 14 Plus.
A laptop that runs hot on the desk tempts people toward a cooling pad, which puts more fans on the desk. Of the fifteen pads our guide to the quietest laptop cooling pads read, not one states a test standard or the distance measured from, so that guide compares each maker's figure only with figures of the same kind.
Declarations can contain errors
Dell publishes two datasheets for the XPS 13, one for each of two regulatory types. Both declare 2.5 bels of mean sound power at idle, yet one gives 16.9 dB of sound pressure and the other 24.9, a gap of 8 dB that Dell does not explain, so both are quoted here.
The XPS 14 and XPS 16 declare identical numbers.
None of this changes the ranking. It is a reminder that a declaration is a document, and documents have errors.
Microsoft, for one: the Surface Laptop 7 eco profile has no acoustic row. We found no declaration from Framework, none from ASUS outside some gaming models covered in our gaming laptops guide, and nothing in the QuickSpecs for HP's OmniBook and Spectre consumer models, though its business EliteBooks carry a noise row. Current Acer models were not confirmed either way.
If you work at a desk with an external keyboard, our explainer on quiet keyboards covers what silent switches and scissor keys change, and why a published noise figure is so rare among keyboard makers.
