Twenty-three free calculators and a guide written by someone who spent a fortune on audiophile gear, sold nearly all of it, and ended up with studio equipment that told him more.
316 models with impedance and sensitivity already converted to one consistent unit — the thing most calculators get wrong before they even start.
Power, voltage swing and difficulty at a listening level you actually use, not at the ear-splitting peak the forums quote.
Usually the answer is no. When it is yes, you get told which of 53 sources will do it — and which will hiss.
Most of the time you do not, and almost nobody will tell you that. The calculator judges your headphones on power and voltage against what a decent dongle really delivers — then says so plainly.
A 600Ω Beyerdynamic runs happily from a phone dongle at sane volume. That is not an opinion, it is arithmetic.
Open the calculatorPower needed at a 100 dB peak. Only the last one genuinely wants a desktop amp.
“You can hear more for a tenth of the price with studio gear.”
A recording engineer, on an audiophile forum — he was right