A high peak-to-average power ratio is a major problem that is inherent in all multicarrier communication systems. Clipping the high-peak power samples introduces (extra) clipping noise, which degrades the system performance in terms of bit-error rate (BER). Measuring the BER usually requires a very long simulation time, as clipping occurs very rarely. We propose a method called clipping noise injection, which allows BER estimation (due to clipping) in discrete multitone-based systems in a fast and quite precise way. Savings of as great as 90% or more are observed in some simulations that are reported. Higher savings are expected when lower BER cases have to be studied.