Solar Cycle 25 Prediction Using Length-to-Amplitude Relations

We propose a simple method for prediction of the 11-year solar cycle maximum that is based on two relations. One them well known Waldmeier's rule binds amplitude and length its ascending phase. The second relates given from minimum to next one. Using corresponding linear regressions we obtain amplitide 25 in scale 13-month smoothed monthly total revised sunspot number ${\rm SN}_{\rm max}(25) = 181\pm46$ moment $T_{\rm 2024.2\pm1.0$. Therefore, according prediction, will be higher than previous one (${\rm max}(24) 116$) with probability 0.92.